MTT2 Instructor Guide

MANUAL TRANSAXLES,
TRANSFER CASES, AND
DIFFERENTIAL CONTROLS
MitsubishiAcademy.com
INSTRUCTOR GUIDE

Course
Guide
MTT2
Instructor
Course Guide
Manual Transaxles,
Transfer Cases, Differentials
Instructor Course Guide
DIAMONDPRO CERTIFIED
TECHNICAL TRAINING
Course Description
This course will familiarize technicians with the current manual
transaxles, transfer cases, and differential assemblies and their controls
systems used in Mitsubishi vehicles.
A solid understanding of the operating principles along with the hands-
on disassembly and reassembly procedures presented here will
improve Mitsubishi technician Fixed Right the First Time performance
and thus, dealership CSI scores.

2Course Guide Mitsubishi Motors North America, Inc.
Manual Transmission and Transfer Case Course Guide - Instructor
Course
Guide
SAFETY IS YOUR RESPONSIBILITY
This section is for use by professional Mitsubishi Motors dealership service technicians. The
descriptions and procedures in this publication supplement existing service manuals, technical
service bulletins, and other documents provided by Mitsubishi Motors North America, Inc.
(MMNA). As a result, the use of these sources may be required to ensure a proper repair.
Within this section there are Notes, Cautions, and Warnings. These references provide guidance
to help you do your job efficiently and safely. The definitions for these terms are listed below.
NOTE
A Note exists to help you do your job more efficiently. A Note may also provide
additional information to help clarify a particular point or procedure.
CAUTION
A Caution alerts you to the possibility of damage to either tools, equipment, or
to the vehicle itself. A Caution recommends that a procedure must be done in
a certain way to avoid potential problems resulting from improper technique or
method.
WARNING
A Warning alerts you to the highest level of risk. Warnings inform you that a
procedure must be done in a particular way to minimize the chances of an accident
that could result in personal injury or even loss of life.
Note
Caution
!
When you see a Note, Caution, or Warning, be sure you understand the message before you
attempt to perform any part of a service procedure. Also keep in mind it is impossible for MMNA
to anticipate or evaluate every service situation a technician may encounter. For that reason, you
have the final responsibility for personal safety–yours and those working around you. Be sure to
always wear proper protective clothing and safety equipment, use the proper tools, and follow
the repair procedures as outlined in various service publications provided by MMNA.
No part of this publication may be reproduced, stored electronically, or transmitted in any form or
by any means without prior written approval from Mitsubishi Motors North America, Inc. MMNA
reserves the right to make changes in the descriptions, specifications, or procedures without
prior notice or obligation.
Copyright © 2015 Mitsubishi Motors North America, Inc.
Corporate Technical Training Department

3Course GuideMitsubishi Motors North America, Inc.
Course
Guide
Table of Contents
Course Title and Code ……………………………………………………………....… 4
Course Length ………………………………………………………………………….. 4
Intended Audience …………………………………………………………………….. 4
Class Size ……………………………………………………………………………….. 4
Student Materials ……………………………………………………………………….. 4
Instructor Materials ……………………………………………………………………... 4
Activity and Demonstration Parts ……………………………………………………… 5
Shop Equipment ………………………………………………………………………… 5
Vehicles ………………………………………………………………………………….. 5
Activity Preparation ………………………………………………………………………6
Course Description ……………………………………………………………………… 7
Course Goals ……………………………………………………………………………. 7
Prerequisites ……………………………………………………………………………. 7
Symbols …………………………………………………………………………………. 8
Student Guide Contents ……………………………………………………………….. 8
Schedule ………………………………………………………………………………… 8
Suggestions for Successful Completion ……………………………………………... 9
Student Evaluation ……………………………………………………………………… 9
Course Achievement Worksheet ……………………………………………………… 10
Personal Safety …………………………………………………………………………. 11
Student Guide Navigation ……………………………………………………………… 12
Prerequisite Review …………………………………………………………………….. 13

Course
Guide
Manual Transaxles, Transfer Cases, and
Differential Controls (MTT2)
3 Days
All Mitsubishi Service Technicians
4-8 participants
MTT2 Student Guide Contents:
• Prerequisite Review Questions
• Section 21.00A - Clutch Operation
• Section 22.01A - Gears, Bearings, and
Synchronizers
• Section 22.02A - F5M42 Transaxle
• Section 22.03B - F5MBB Transaxle
• Section 22.04B - F5MBD Transaxle
• Section 22.05B - W5M6A Transaxle
• Section 22.06A - Transfer Cases & Differential
Control Systems
• Daily Quizzes
• Course Achievement Worksheet
• Name Tents
• MTT2 Instructor Guide
• PowerPoint Slides
Videos used in this course are linked to movie
projector icons and located on the slides where
the clips are to be shown. To use this feature, follow
these steps before class begins.
Step 1: Before opening the MTT2 PowerPoint file,
open Windows Media Player and maximize to full
screen. Leave it run in the background during the
entire PowerPoint presentation.
(Don’t close the media player.)
Step 2: Open the MTT2 PowerPoint file.

Step 3: To play a video clip, click the projector icon
on the slide. When the clip is finished
playing, press ALT ESC on the keyboard
to return to the current PowerPoint slide.
This feature keeps the media player running in full
screen mode and eliminates opening, closing, and
resizing the player for each video clip.
Course Title and Code
Course Length
Intended Audience
Class Size
Student Guide Materials
Instructor Materials

Course
Guide
• Push Type Clutch (1)
• Pull Type Clutch (1)
• Clutch Release Bearing (instructor choice)
• Clutch Slave Cylinder (instructor choice)
• DOT 3 or DOT 4 Brake Fluid
• F5MBB Transaxles (2)
• F5MBD Transaxles (2)
• W5M6A Transaxles (2)
• ACD Hydraulic Control Unit (1)
• Steering Angle Sensor (if available)
• AYC Rear Differential (1)
• ACD/AYC Hydraulic Control Unit (1)
• Active Rear Differential Electronic Coupling (1)
• Super Select Transfer Case Cover (1)
• Hydraulic Press
• Special Tools (identified in each Skill Section)
• Petroleum Jelly
• MUT-III Scan Tool (2)
• Feeler gauges (2)
• Snap Ring Pliers (2)
• Hand Tools
• Outlander or Outlander Sport (AWD)
• Lancer Ralliart
Activity and Demonstration Parts
Shop Equipment
Vehicles

Course
Guide
Instructor Preparation Section 21.00A - Clutch Operation
• Gather pass around parts.
• Lecture with Section 1 PowerPoint slides.
Section 22.01A - Gears, Bearings, Synchros
Section 22.02A - F5M42 Transaxle
Section 22.03B - F5MBB (ZC) Transaxle
• Verify Special Tools and hand tools are
available.
Section 22.04B - F5MBD (EL) Transaxle
available.
Section 22.05B - W5M6A (EVO) Transaxle
• Play W5M6A video (W5M6A.avi) before
students begin the Skill Section
available.
Section 22.06A - Transfer Cases and
Differential Control Systems
• Gather pass around parts
• Vehicles
• MUT-III Scan Tools

Course
Guide
COURSE DESCRIPTION
The course details the operation of manual
transaxles, transfer cases, and differential
control systems used with Mitsubishi vehicles.
A solid understanding of the topics presented
here will improve the technician’s Fixed-Right
First Time performance and dealership CSI
scores.
COURSE GOALS
• Describe clutch operation and principles of
diagnosis / repair.
• Describe gear ratio characteristics, gear
designs, and diagnosis.
• Identify synchronizer designs and appropriate
diagnosis procedures.
• Identify various bearing designs, their uses,
and diagnosis procedures.
• Familiarize technicians with transaxle
operation and diagnosis.
F5M42, F5MBD, F5MBB, W5M6A
• Familiarize technicians with transfer case
operation and diagnosis.
• Familiarize technicians with differential control
systems.
PREREQUISITES
Successful completion of the following courses
is required for enrollment in this course. Consult
MitsubishiAcademy.com for details.
• Electrical Systems 1 (ES1 or ELFB or ES1W)
• MEDIC 2 (MED2)
• MEDIC 3 (ME3W)
• Scan Tool Viewer (STV or STV 2 or STV3)
• Manual Transmission Fundamentals (MTFW)
Student Course Guide-3a
Student Course Guide-3b
Student Course Guide-3c

Course
Guide
SCHEDULE • Prerequisite Review
• Clutch Operation
• Gears, Bearings, and Synchronizers
• F5M42 Transaxle
• F5MBB Transaxle
• F5MBD Transaxle
• Day 1 Exam
• W5M6A Transaxle
• Transfer Cases & Differentials
• Day 2 Exam
• Transfer Cases & Differentials (cont.)
• Day 3 Exam
DAY 1
DAY 2
SYMBOLS
Symbols are used throughout the course to aid in
navigating the sections.
The Student Guide includes the following elements.
• Prerequisite Review Questions (Front pocket)
• Name Tent (Front pocket)
• Day 1, Day 2, and Day 3 Quizzes (Front pocket)
• Course Achievement Worksheet (Front pocket)
• Course Guide
• Section 21.00A - Clutch Operation
• Section 22.01A - Gears, Bearings and Synchros
• Section 22.02A - F5M42 Transaxle
• Section 22.03A - Transfer Cases
• Section 22.04B - F5MBB and F5MBD Transaxles
• Section 22.05B - W5M6A Transaxle
• Section 22.06A - Transfer Cases & Differential
Control Systems
CSI
Pay special attention to these details as
they help Diagnose Customer Concerns
correctly to Fix It Right The First Time.
Activity Perform the related activity and answer the
related questions.
Feedback
Complete the Knowledge Check to verify
your understanding of the materials.
Slide Course Guide-4a
Slide Course Guide-4b
STUDENT GUIDE CONTENTS
DAY 3

Course
Guide
Take advantage of your time during this course
to get the most from it.
Make notes or drawings any place in the Student
Guide to help recall the details later.
One of the main goals of Mitsubishi Training
is to provide as much individual instruction as
possible. If you do not understand something
in the classroom or shop, ask your instructor to
clarify the point.
Hands-on activities offer the opportunity to work
as part of a team. Rotate your roles in the team
so that everyone has a chance to complete the
exercise. Only by actively participating will you
learn from the experience.
The training course is an opportunity to learn
successfully in a controlled environment under
the guidance of a trained instructor. Learn from
your mistakes, practice good safety habits, and
use equipment and vehicles properly. Have
a good experience here and return to your
dealership with confidence in your abilities as a
trained professional.
Because Mitsubishi technical training is
competency based, hands-on activities
comprise 45% of the student’s evaluation.
The instructor will observe and evaluate each
technician’s performance, offering assistance
when necessary.
Summaries and Knowledge Check questions
wrap up each course section. Technician
participation in these activities comprises an
additional 10% of the evaluation.
Daily exams contribute to the final 45% of the
evaluation.
SUGGESTIONS FOR
SUCCESSFUL COMPLETION
Spend the Time Wisely
Take Notes
Ask Questions
Teamwork
Learn From Your Mistakes
STUDENT EVALUATION
Skill & Diagnosis Activities
Summaries and Knowledge Checks
Written Exams
Student Course Guide-5a
Student Course Guide-5b

Course
Guide
COURSE ACHIEVEMENT
WORKSHEET
Manual Transaxles and Transfer Cases (MTT2)
Technician Course Achievement Worksheet
Student Name: _________________________ Course Dates: _______________________________________
SKILL ACTIVITIES (60%) Possible Instructor’s Actual
Points Verification Points
F5MBB Transaxle Assembly 10 _______ _____
F5MBD Transaxle Assembly 10 _______ _____
W5M6A Transaxle Assembly 10 _______ _____
Transfer Case Electronic Diag 15 _______ _____
Total 45 _______ _____
Instructor Comments:
QUIZZES (30%)
Day 1 Quiz (15 points possible) _______
(45 points possible) _______
FINAL GRADE SUMMARY
(Minimum 80% = Passing Score)
Skill Activities (45 points) _______
Quizzes (45 Points) _______
Participation (10 points) _______
TOTAL _______
Mitsubishi Motors North America, Inc. 03/2015
Dealer Name: __________________________ Dealer Code: __________ Instructor: __________________
Course Guide-6a

Course
Guide
PERSONAL SAFETY
NOTE
ANote exists to help you do your job more efficiently.
A Note may also provide additional information to
help clarify a particular point or procedure.
CAUTION
A Caution alerts you to the possibility of damage
to either tools, equipment, or to the vehicle itself.
A Caution recommends that a procedure must be
done in a certain way to avoid potential problems
resulting from improper technique or method.
WARNING
A Warning alerts you to the highest level of risk.
Warnings inform you that a procedure must be
done in a particular way to minimize the chances
of an accident that could result in personal injury or
even loss of life.
Within the student guide are Notes, Cautions, and
Warnings. These references provide guidance
for job efficiency and safely. Definitions for these
terms are listed below.
Note
Caution
!

Course
Guide
Slide Numbers
Numbers at the lower right corner of each
slide aid in student guide navigation.
• Section number indicates the topic.
• Student Guide page number follows.
• Completing the identification is a lower
case letter indicating the position
on the slide on the page:
a = Top
b = Middle
c = Bottom
22.00A = Clutch Operation
9 = Section page #
a = Top of page
STUDENT GUIDE NAVIGATION
Printed on the edge of each page are
section number tabs (for example,
22.03A as shown at right).
Page numbers are located on the
lower outside corner of each page (for
example, 22.03A 16 as shown at right).
Simply thumb through the pages to find a
specific page number. Slide Course Guide-8a
Slide Course Guide-8b
Pressure Plate Diaphragm
Clutch Pedal Depressed
(Clutch Disengaged)
Release Bearing
Movement (Pull)
Pivot Point
Clutch Disc
Clutch Release Fork
Transaxle Input Shaft
21.00A-9a

Course
Guide
To ensure the information presented in the
prerequisite courses (ES1, MEDIC, STV, and
MTFW) has been mastered, students will complete
the enclosed review questions. It does not count
toward the final score but is useful for reviewing
elements of electrical system basics, the use
of Mitsubishi’s scan tool, and technician ability
to research information using MEDIC. With the
previously completed courseware thoroughly in
mind, all students begin the Climate Control course
fully prepared.
PREREQUISITE REVIEW

21.00A
TECHNICAL TRAINING
Instructor Guide
Clutch Operation
Section Description
This section details clutch operation and the activation mechanisms
used with Mitsubishi vehicles. This includes the flywheel, pressure
plate, and clutch disc. Also explained are pull-type vs. push-type
clutches.
Theory Section
21.00A

1Section 21.00A Mitsubishi Motors North America, Inc.
Manual Transaxle Clutch Operation21.00A
NOTE
CAUTION
method.
WARNING
Note
Caution
!

2Section 21.00AMitsubishi Motors North America, Inc.
Manual Transaxle Clutch Operation
21.00A
Table of Contents
Section Introduction
Section Goal ………………………………………………………………...…… 3
Section Objectives ………………………………………………………………. 3
Needed Materials ……………………………………………………………….. 3
Time to Complete ……………………………………………………………….. 3
Clutch Overview ..……….………………….…………………………………………… 4
Function …………………………………………………………………………………. 5
Push-Type Clutch Components and Operation …………………..…………………. 6
Pull-Type Clutch Components and Operation ……………………………………….. 8
Flywheel …………………………………….…………………………………….……… 11
Clutch Assembly ………………………………………………………………………… 12
Clutch Disc ………………..…………………………………….……………………….. 13
Release Bearing ……………………………………………………………….……...… 14
Pilot Bearing …….…..…………………………………………………………………… 16
Cable Clutch Control System ………………………………………………………….. 16
Starter Interlock Switch …………………………………………………………………. 19
Cruise Control and One-touch Start Interlock Switch ………………………………. 20
Cable Clutch System Adjustments ……………………………………………………. 21
Hydraulic Clutch Control ………………………………………………………………...22
Master Cylinder …………………………………………………………………………. 23
Slave Cylinder …………………………………………………………………………… 24
Concentric Slave Cylinder ……………………………………………………………… 25
Hydraulic Fluid ………………………………………………………………………….. 26
Hydraulic Clutch System Bleeding ……………………………………………………. 27
Hydraulic Clutch System Adjustments ……………………………………………….. 29
Clutch Inspection Areas ………………………………………………………………... 30
Section Summary ………………………………………………………………………. 31
Knowledge Review Questions ………………………………………………………… 35

SECTION GOAL
SECTION OBJECTIVES After completing this section, you will be able to
perform the following tasks.
• identify the components of both push-type and
pull-type clutch designs.
• explain the unique method of disengaging the
clutch release bearing for transaxle
removal.
• explain the reason small amounts of slipping in
a clutch is normal.
• describe the components that operate when
the clutch is released (pedal down) and
engaged (pedal up).
• identify the two friction surfaces against which
the clutch disc operates.
• identify the components that force the clutch
disc against the flywheel.
• explain the purpose of a pilot bearing in RWD
transmission applications.
• identify the clutch component subject to the
highest wear.
• identify the proper hydraulic fluid required.
• identify the components of a hydraulic clutch
control system.
• describe clutch adjustment procedures.
NEEDED MATERIALS
TIME TO COMPLETE
Section 21.00A only.
About 2 hours
Slide 21.00A-3a
Slide 21.00A-3b
This section details clutch operation and the
activation mechanisms used with Mitsubishi
vehicles. This includes the flywheel, pressure
plate, and clutch disc. Also explained are pull-
type vs. push-type clutches.
t

21.00A
Clutch Overview
Slide 21.00A-4a
Thepurposeoftheclutchistoengageanddisengage
power from the engine to the transmission. The
clutch allows the driver to gradually apply engine
torque to the driveline when the vehicle first starts
out. The clutch also allows the driver to momentarily
disconnect engine torque so the transmission and
driveline are not damaged during gear shifts. Finally,
the clutch allows the driver to disconnect the engine
from the driveline when the transmission is in gear
and/or the vehicle is stopped.
Currently Mitsubishi uses a single dry friction disc
operated by a clutch pedal through a hydraulic
control system.

The driver releases the clutch by depressing the
clutch pedal. To prevent the engine from over-
revving with no load on it, the driver should also
release the accelerator pedal.
The driver engages the clutch by gradually releasing
the clutch pedal while slowly depressing the
accelerator pedal as the load on the engine
increases.
When the driver depresses the clutch pedal, engine
power is disconnected from the transmission to
allow engine starting, idling in gear at a stop,
changing gears or reversing vehicle direction.
When the driver releases the clutch pedal, engine
power is applied to the transmission to propel the
vehicle.
Slide 21.00A-5a
Clutch Released
(Pedal Down)
AcceleratorClutch
Clutch Engaged
(Pedal Up)
Function

21.00A
Slide 21.00A-6a
Currently, Mitsubishi uses a push-type clutch
(shown above and below) for most applications.
Push-Type Clutch
Components and Operation
Flywheel
Clutch
Disc
Pressure
Plate
Release
Fork
Release
Bearing
Return
Spring
When the clutch pedal is released (up), the
diaphragm spring forces the clutch disc (splined
to the transaxle input shaft) tightly between the
flywheel and the clutch pressure plate. The clutch
assembly then rotates at crankshaft speed. While
engaging and disengaging the clutch, the disc slips
slightly until the input shaft reaches crankshaft
speed. A small amount of slip is normal and
provides a smooth engagement. Excessive slip
will quickly wear out the disc’s friction material, and
in severe cases, wears the flywheel and pressure
plate as well.
Slide 21.00A-6b

When released, a cable or hydraulic slave cylinder
operates the clutch release fork, forcing the release
bearing against the diaphragm spring fingers.
These fingers pivot and move the pressure plate
away from the clutch disc. With the engine running,
the pressure plate and the release bearing spin, but
the disc is free to stop.
Slide 21.00A-7a
Clutch Released (Pedal Down)
Clutch Pedal Down
(Clutch Released)
Release Bearing
Movement (Push)
Pivot Point
Clutch Disc
Clutch Release Fork
(Clutch Engaged)
Release Bearing
Movement (Push)
Pivot Point
Clutch Disc
Clutch Release Fork
Slide 21.00A-7b
As the pedal is released, the release fork allows
the diaphragm fingers to push the release bearing
back, causing the spring to squeeze the clutch disc
friction surfaces between the pressure plate and
the flywheel. Since the clutch disc is splined to the
input shaft, the shaft now rotates at engine speed.
Clutch Engaged (Pedal Up)

21.00A
Used with 2000-2005 Eclipse Spyder and 2003
and newer Lancer Evolution, a pull-type clutch is
shown in the drawing above and picture below.
Slide 21.00A-8a
Pull-Type Clutch
Components and Operation
The requirement to increase pressure plate
diaphragm spring tension (clamping force) while
maintaining low pedal effort was met by replacing
the push-type clutch with a pull-type design. By
increasing the distance between the force point
and the pivot point, the effort required to compress
the diaphragm springs is reduced because of the
higher mechanical advantage.
Slide 21.00A-8b
Flywheel
Clutch
Disc
Pressure
Plate
Release
Fork
Release
Bearing
Return
Spring
Return
Spring

Slide 21.00A-9a
Clutch Engaged (Pedal Up)
(Clutch Disengaged)
Release Bearing
Movement (Pull)
Pivot Point
Clutch Disc
Clutch Release Fork
When the pedal is depressed, the clutch fork pulls
the release bearing and diaphragm spring away
from the flywheel. As the diaphragm spring pivots,
the pressure plate moves away from the clutch disc.
Clutch Pedal Released
(Clutch Engaged)
Release Bearing
Movement (Pull)
Clutch Disc
Clutch Release Fork
Pivot Point
Slide 21.00A-9b
As the pedal is released, the release fork allows the
clutch release bearing, and pressure plate to move
toward the flywheel. The diaphragm spring pivots
pressing the disc against the flywheel which causes
the clutch assembly and transaxle input shaft to
turn at engine speed.

21.00A
Slide 21.00A-10a
With the pull-type clutch, the release bearing is
mechanically connected to the clutch diaphragm
spring. Before removing the transaxle, the clutch
release bearing must be disengaged from the clutch
diaphragm spring.
As discussed in the Tech Talk article (Volume 80)
follow these procedures to release the lock ring
retaining the throw out bearing to the diaphragm
spring.
1. Remove the rubber plug in the bell housing.
2. Insert a long flat-blade screwdriver into the
access hole between the bearing and the gold-
colored retaining ring.
3. Press the release fork slightly toward the
transaxle while twisting the screwdriver
counterclockwise and depressing the
gold-colored ring. The ring should move
forward and release from the diaphragm.
Reinstall the transaxle. To engage the clutch
release bearing with the diaphragm spring, simply
move the clutch fork toward the transaxle until the
ring pops into the groove of the bearing inner race.

Flywheel
Slide 21.00A-11a
The flywheel is a large steel disc bolted to the end
of the crankshaft. It is used to dampen engine
vibration from cylinder firing pulsations and acts
as one friction surface for the clutch disc to work
against. The flywheel also draws off heat from the
clutch disc.
Contact between the flywheel and disc will naturally
cause hot spots, grooves, thermal cracks and/or
concave warpage. Except with stepped flywheels,
resurfacing to remove minor grooves or scoring can
be performed, as long as no more than 0.020 in.
(0.5 mm) is removed. After machining, make certain
any clutch alignment dowel pins are reinstalled.
Removing too much metal may result in a no-
release condition, since the flywheel and clutch
assembly has been moved away from the release
mechanism. An over-machined flywheel can also
destroy the heat sink capacity. Conversely, if the
flywheel is not returned to like-new flat condition,
power transfer and component life will be minimized
by chatter, slipping, and heat build-up.
Some flywheels utilize a step configuration, where
the flywheel mounting surface is higher or lower
than the actual wear surface. It is imperative to
maintain the proper step or recess dimension.
Some Mitsubishi vehicles have used flexible (dual
mass) flywheels to further reduce vibration.
Flywheel Inspection

21.00A
Clutch Assembly
Slide 21.00A-12a
Pressure
Plate
Diaphragm
Spring Clutch Cover
The clutch cover assembly bolts to the flywheel and
rotates at engine speed. The diaphragm spring is a
large conically shaped spring that forces the
pressure plate against the clutch disc under enough
pressure to prevent the clutch from slipping under
full engine torque. The pressure plate is a machined
disc that bears on the clutch disc friction surface
when the clutch is engaged.
Thepressureplateissusceptibletowear,particularly
when the clutch is operated without sufficient free
play. It can also be damaged by a severely worn
clutch disc and from overheating due to clutch
slippage.
Inspect the pressure plate for cracks, grooves,
burned areas, scoring, and warpage. Also check for
broken or worn diaphragm springs.
Slide 21.00A-12b
Check the diaphragm spring ends for wear and
uneven height. Replace the clutch cover if wear is
evident or height difference exceeds 0.020 inch.
Clutch Cover Inspection

Slide 21.00A-13b
Clutch Disc
Slide 21.00A-13a
The clutch disc is comprised of a metal hub
splined to the input shaft of the transmission, and
a thin metal disc faced with friction material. Small
torsional springs connect the hub to the metal disc,
and help cushion clutch engagement for smoother
operation without chattering.
Rivet Depth
Check for loose rivets, uneven contact, evidence of
seizure, or oil contamination. If defective, replace
the clutch disc. Replace the clutch disc if the rivet
depth reading is less than 0.012 inch. Check the
torsion springs for play and damage. If defective,
replace the clutch disc. Place the clutch disc on
the input shaft and verify it slides easily along the
splines. If poor sliding condition is evident, clean,
reassemble, and recheck. If excessive play is
evident, replace the clutch disc and/or input shaft.
Clutch Disc Inspection

21.00A
Release Bearing
Slide 21.00A-14a
The release bearing, also called a “throw-out”
bearing, is a permanently lubricated and sealed
ball-type thrust bearing. The release fork forces
the release bearing against the release fingers to
disengage the clutch.
Since the release bearing is permanently lubricated,
it should never be cleaned with solvent as this could
destroy the lubricant.
Depress the pedal until the clutch just engages.
This is the point where the release bearing is just
contacting the pressure plate fingers. If a squealing
or chirping sound is heard, suspect a worn release
bearing.
Release Fork and
Cross Shaft
Release Bearing Inspection
(Noise)
Clutch
Disc
Pressure
Plate
Release
Fork
Release
Bearing
Return
Spring
Slide 21.00A-14b
As with this Mirage example, a cable operated
clutch uses a cross shaft spanning the bell housing
either horizontally or vertically. A cable connects
to a large lever at one end of the shaft. A release
fork is pinned to the shaft and fitted with one or
more springs to return the clutch to its disengaged
position.

Instructor Note:
Lead a discussion of components which
should be inspected during clutch service.
Clutch
Disc Pressure
Plate
Release
Fork
Release
Bearing
Return
Spring
Return
Spring
Slave
Cylinder
Cross
Shaft
Some hydraulic systems use a cross shaft. A slave
cylinder operates the release shaft lever instead of
a cable as in this Lancer Evolution example.
Slide 21.00A-15a
Clutch
Disc Pressure
Plate
Release
Fork
Release
Bearing
Release
Fork Pivot
Slave
Cylinder
Slide 21.00A-15b
Some vehicles (2.4L Eclipse shown) use a release
fork that pivots on a fulcrum screwed into the clutch
housing. The forked end fits behind the release
bearing. The other end protrudes through the clutch
housing and connects to a hydraulic slave cylinder.
Wear Inspection Areas
Release
Bearing
Return Springs
Cross
Shaft
Bushings
Shims
Front
Bearing Retainer
Release
Fork Pivot
Inspect the areas shown above for wear. Replace
as necessary.
Slide 21.00A-15c

Instructor Note:
Use this slide to explain clutch operation
as detailed on the following page.
21.00A
Slide 21.00A-16a
Pilot Bearing
Crankshaft
Input Shaft
Pilot Bearing
Used with Raider, a pilot bearing mounts inside the
crankshaft rear flange to support the transmission
input shaft. This added support ensures that the
clutch disc stays in proper alignment with the
pressure plate and flywheel.
Typically a pilot bushing is used with transaxles.
Slide 21.00A-16b
CABLE CLUTCH CONTROL
Cable
Connection
Snap Pin
Clevis Pin
Pedal
Stops
Interlock
Switch
(Stater)
Interlock
Switch
(OSS & Cruise Control)
Clutch Pedal
Freeplay
Adjustment
The cable clutch control system provides a
mechanical link between the clutch pedal and the
clutch release lever. The system is designed to
provide a mechanical advantage to decrease pedal
effort disengaging the clutch.

As the clutch pedal is depressed, the pedal pivots
on the support shaft, and pulls the inner clutch
cable toward the rear of the vehicle. Since the cable
connects to the clutch release lever mounted in
the bell housing, the lever and fork rotate forward,
releasing the clutch. The cable sheath is held
stationary by a cable bracket on the transmission.
As the clutch pedal is released, a return spring
mounted on the clutch release lever pulls the lever
and the release fork to the rear. When the release
lever moves, it pulls the inner cable toward the
transaxle. This pulls the clutch pedal back until it
contacts a stop bolt. The stop bolt is adjustable and
establishes clutch pedal height. Models with One-
touch Start System (OSS) and cruise control have
a switch attached to the stop bolt to indicate when
the clutch is disengaged.
Clutch Released (Pedal Up)
Clutch Cable
Free Play Adjustment
A
Clutch Cable
Adjustment Nut
Bushing Protrusion
Slide 21.00A-17a
AsusedwithcurrentMirage,thefreeplayadjustment
nut sets the clutch pedal free play by moving the
outer cable toward or away from the cable holder.
This adjusts the overall length of the cable sheathing
to compensate for cable stretch and clutch disc
wear. A certain amount of free play is necessary to
ensure that the clutch is fully engaged.
Further adjustment details are located on page 21
of this section.

21.00A
Release Lever Shaft and Fork
Slide 21.00A-18a
Clutch Cable
Attachment
Release Fork
Release
ShaftRoll Pin
The clutch cable connects to the release lever shaft
which pivots the release fork. Two roll pins, or spring
pins, secure the release fork to the release lever
shaft.
.
Return
Spring
Roll Pins
Slide 21.00A-18b
A coil spring returns the clutch to its engaged
position when the driver lets up on the clutch pedal.
The roll pins can break resulting in the release fork
rotating on the shaft. The clutch lever operates, but
the clutch won’t disengage. To minimize breakage,
the roll pins should always be installed so the split
lines up with the direction of force.

Starter Interlock Switch
Slide 21.00A-19a
The Starter Interlock Switch prevents starting the
engine unless the clutch pedal is depressed. This
prevents the vehicle from lurching forward if clutch
is engaged with the transaxle in gear.
Ohmmeter
Connection
Pedal Position Specification
Fully Depressed
Released
2 ohms or less
Open Circuit
1-2
ENGINE
CONTROL
MODULE
OSS-ECU
VEHICLES
WITHOUT KOS
VEHICLES
WITH KOS
IGNITION SWITCH (ST)
JUNCTION
BLOCK
BATTERY
STARTER
FUSIBLE
LINK
RELAY
BOX
SBF3
STARTER
RELAY
CLUTCH
INTERLOCK
SWITCH
(STARTER RELAY)
JOINT
CONNECTOR (2)
Slide 21.00A-19b
The Starter Interlock circuit used with the current
Mirage is shown above.

21.00A
Slide 21.00A-20b
Interlock Switch (Cruise Control and
One-touch Start System)
Slide 21.00A-20a
Ohmmeter
Connection
Pedal Position Specification
Fully Depressed
Released 2 ohms or less
Open Circuit1-2
ENGINE
CONTROL
MODULE
CRUISE CONTROL SWITCH
CLOCK
SPRING
(FUSE )7
TAILLIGHT
RELAY
THROTTLE BODY ASSEMBLY
<M/T>
OSS-ECU
ACCELERATOR
PEDAL POSITION
SENSOR
HALL IC
(MAIN)
HALL IC
(SUB)
CLUTCH
INTERLOCK SWITCH
(FOR CRUISE
CONTROL SYSTEM
AND OSS)
HALL IC
(SUB)
HALL IC
THROTTLE POSITON
SENSOR
(MAIN)
THROTTLE
ACTUATOR
CONTROL
MOTOR
This interlock switch signals the ECM to disengage
cruise control operation when the clutch pedal is
depressed.
The Cruise Control and OSS Interlock circuit used
with the current Mirage is shown above.

Cable Clutch System Adjustments
Slide 21.00A-21a
Slide 21.00A-21b
Same
Height
Brake
PedalClutch
Pedal
Typically two adjustments are possible on vehicles
equipped with cable operated clutch controls.
• Clutch Pedal Free Play
• Clutch Pedal Height
Note
Pedal HeightFree Play Engagement
Some older vehicles use a Stop Bolt for pedal
height adjustment. Additionally, if one of these
older vehicles is equipped with cruise control, the
Cruise Control Switch replaces the Stop Bolt.
The clutch and brake pedal heights should be
the same for safe operation of the vehicle. Verify
the brake pedal and stop light switch are properly
adjusted according to service manual Group 35. If
necessary, adjust the clutch pedal height to make
them even.

Instructor Note:
Use this slide to explain clutch operation
as detailed on the following page.
21.00A
Adjustments (continued)
Slide 21.00A-22a
Consult service manual Group 21 for the applicable
model being repaired for adjustments to Free Play,
Pedal Height, and Engagement.
If the clutch pedal height and the gap between
the pedal and floor board when the clutch begins
to engage exceed specifications, check the clutch
pedal, clutch cable, and clutch assembly, for
damage or wear. Replace as necessary.
HYDRAULIC CLUTCH CONTROL
Master Cylinder
Slave Cylinder
Brake Master
Cylinder Reservoir
Fluid Supply Hose
Hydraulic clutch controls form a link between the
clutch pedal and the clutch release lever to operate
the clutch. Shown above is a 2005 Lancer Evolution.
The hydraulic system automatically compensates
for clutch system wear, making periodic adjustments
unnecessary.
Hydraulic clutch control provides the driver with a
mechanical advantage by converting a light force
at the pedal to a greater force at the clutch release
cylinder with operates the clutch.

Slide 21.00A-23a
When the clutch pedal is depressed, the master
cylinder forces hydraulic fluid through an aluminum
line and rubber hose to the release (slave) cylinder.
The release cylinder moves the clutch release lever
to release the clutch.
As the clutch pedal is released, diaphragm spring
pressure forces the release fork back, which in turn
causes the slave cylinder piston to force fluid back
to the master cylinder. Since the hydraulic lines are
kept full of fluid, this automatically compensates
for worn clutch components. This feature makes
periodic free play adjustments unnecessary.
Clutch Released (Pedal Up)
Master Cylinder Operation
Piston
Cylinder
Piston
Stop
Ring
Boot
Pushrod
Fluid Inlet
Bleeder Screw
The master cylinder consists of the cylinder body,
piston, pushrod, and a fluid reservoir. The pushrod
connects directly to the clutch pedal with a clevis
pin. As the clutch pedal is depressed, the pushrod
forces the piston down the cylinder bore. This forces
hydraulic fluid out of the cylinder bore under great
pressure to operate the slave cylinder.
As the cylinder bore and piston wear, more hydraulic
fluid is required. The reservoir ensures the hydraulic
system remains full to compensate for wear.
The master cylinder is constructed using aluminum
or plastic and cannot be honed. If the bore is in
good condition, some aluminum master cylinders
can be rebuilt using available kits from Mitsubishi.
Some master cylinders (3.0L V6 Eclipse, for
example) include a clutch pedal damper to reduce
pedal vibration.

21.00A
Slide 21.00A-24a
Bleed Screw
Inlet from
Master
Cylinder
Pushrod
The slave cylinder also consists of a cylinder body,
piston and push rod. Hydraulic fluid under pressure
from the master cylinder enters the cylinder behind
the piston. This forces the piston and pushrod out.
The pushrod connects to the clutch release lever,
and disengages the clutch.
The slave cylinder incorporates a bleed screw used
to remove air from the clutch hydraulic system.
Most slave cylinders are cast iron and can be rebuilt
with kits from Mitsubishi.
Slave Cylinder Operation

Slide 21.00A-25a
Concentric Slave Cylinder (CSC)
CSC Adapter
Concentric Slave Cylinder (CSC)
Used on some Mitsubishi vehicles since 2002,
the Concentric Slave Cylinder (CSC) is designed
to operate directly on the clutch diaphragm and
eliminates the release fork, pivot, and externally-
mounted slave cylinder.
Mounted inside the clutch housing and surrounding
the input shaft, the hydraulic cylinder presses the
incorporated release bearing against the diaphragm
to disengage the clutch. An adapter is used to
lengthen the fluid supply tube.
The system automatically compensates for wear,
making periodic adjustments unnecessary.

21.00A
Slide 21.00A-26a
Hydraulic Fluid
Hydraulic fluid must meet DOT 3 or DOT 4
specifications. This fluid does not compress when
the clutch pedal is depressed. However, if the fluid
becomes contaminated with moisture, dirt or other
materials, it may become slightly compressible as
evident by a “spongy” feel to the clutch pedal. Air
in the system will also cause failure. Under these
conditions, it may not be possible to completely
disengage the clutch, leading to eventual clutch
failure.
Since the same hydraulic fluid is used in the clutch
and brake systems, the same precautions apply:
• Clean clutch parts with denatured alcohol or a
brake cleaning solvent. Dry the parts thoroughly.
Never use petroleum based solvents for cleaning.
• Always use DOT3 or 4 fluid. Don’t mix fluids.
• Keep the reservoir cap on tightly except when
topping up the fluid level to prevent moisture and
dirt from contaminating the fluid in the system.
• Keep the hydraulic fluid container tightly capped
when not in use to prevent moisture and dirt
contamination. Hydraulic fluid is hygroscopic
meaning it absorbs moisture from the air when
exposed.
Commercially available testers, like this OTC unit,
can be used to verify the moisture content of brake
fluid.

Bleeder Screw
Bleeder Screw
Conventional Slave Cylinder Concentric Slave Cylinder (w/o Adapter)
Slide 21.00A-27a
Hydraulic Clutch System Bleeding
Whenever a clutch assembly is service, the
hydraulic system should be bled.
Steps for bleeding a stand-alone slave cylinder
and Concentric Slave Cylinder without adapter.
1. Connect a plastic tube from the bleeder port to
a clear container partially filled with brake fluid.
Make certain the end of the tube is submerged
below the fluid level in the container during the
bleeding procedure.
2. Depress the clutch pedal slowly. (No need to
pump the pedal.)
3. Open the bleeder screw to release air and fluid.
4. Close the bleeder screw.
5. Release the clutch pedal.
6. Repeat steps 2 through 5 until no air bubbles
are noted flowing from the tube.
7. Maintain brake reservoir level between “MAX”
and “MIN” throughout the bleeding process.

21.00A
Slide 21.00A-28a
Bleeder Port
Bleeder Valve
Conventional Slave Cylinder
and Adapter
Concentric Slave Cylinder
Adapter Bleed Port and Valve
Steps for bleeding a Concentric Slave Cylinder
with CSC Adapter.
1. Connect a plastic tube from the Bleeder Port to
a clear container partially filled with brake fluid.
Make certain the end of the tube stays
submerged below the fluid level in the
container during the bleeding procedure.
2. Depress the clutch pedal slowly. (No need to
pump the pedal repeatedly.)
3. By hand, turn the Bleeder Valve
counterclockwise (about 1/2 turn) to
release air and fluid.
4. Close the bleeder valve.
5. Release the clutch pedal.
6. Repeat steps 2 through 5 until no air bubbles
are noted flowing from the tube.
7. Maintain brake reservoir level between “MAX”
and “MIN” throughout the bleeding process.
Hydraulic Clutch System Bleeding
(continued)

Same
Height
Brake
PedalClutch
Pedal
Hydraulic Clutch
System Adjustments
As with cable control systems, some adjustments
can be made to hydraulic systems. Typically these
include Clutch Pedal Height, Clutch Pedal Clevis
Pin Play, and Clutch Pedal Free Play. Unlike
cable systems, these adjustments are not made
due to system component wear. Consult Group 21
of the applicable service manual for details.
Slide 21.00A-29a

21.00A
Clutch Inspection Areas When inspecting clutch assemblies, technicians
should look at the following areas.
Clutch Disc
• Disc runout
• Depth of the friction material from the rivets
• Oil or grease saturation
• Worn or loose friction material
• Broken dampening springs
• Worn or rusted clutch hub splines
Release Bearing
• Smooth bearing rotation
• Damage to clutch fork retaining grooves
• Grooves on front bearing retainer
Clutch Fork
• Excessive wear on fingers which contact
release bearing
• Bent release bearing fingers
• Damaged or excessively worn pivot
Pilot Bearing (Montero, Raider)
• Smooth bearing rotation
• Rust
• Damage to input shaft from bearing
seizure
Pressure Plate Assembly
• Warpage (runout)
• Hot spots or heat cracks
• Damaged diaphragm or coil springs
• Damaged diaphragm fingers where
they contact the release bearing
Flywheel
• Excessive runout
• Hot spots or heat cracks
• Grooves
• Flywheel ring gear damage

The clutch engages and disengages power from
the engine to the transmission. It allows the driver to
gradually apply engine torque to the driveline when
the vehicle first starts out. The clutch also allows
the driver to momentarily disconnect engine torque
so the transmission and driveline are not damaged
during gear shifts. Finally, the clutch allows the
driver to disconnect the engine from the driveline
when the transmission is in gear and/or the vehicle
is stopped.
Mitsubishi uses a single dry friction disc operated
by a clutch pedal through a hydraulic control system.
A push-type clutch for most vehicles except high
performance applications.
When released, a cable or hydraulic slave cylinder
operates the clutch release fork, forcing the release
bearing against the diaphragm spring fingers.
These fingers pivot and move the pressure plate
away from the clutch disc. With the engine running,
the pressure plate and the release bearing spin, but
the disc is free to stop.
As the pedal is released, the release fork allows
the diaphragm fingers to push the release bearing
back, causing the spring to squeeze the clutch disc
friction surfaces between the pressure plate and
the flywheel. Since the clutch disc is splined to the
input shaft, the shaft now rotates at engine speed.
A pull-type clutch is used with 2000-2005
Eclipse Spyder as well as 2003 and newer Lancer
Evolution to increase pressure plate clamping force
while maintaining low pedal effort. By increasing
the distance between the force point and the pivot
point, the effort required to compress the diaphragm
springs is reduced because of the higher mechanical
advantage.
When the pedal is depressed, the clutch fork pulls
the release bearing and diaphragm spring away
from the flywheel. As the diaphragm spring pivots,
the pressure plate moves away from the clutch disc.
Section Summary

21.00A
As the pedal is released, the release fork allows the
clutch release bearing, and pressure plate to move
toward the flywheel. The diaphragm spring pivots
pressing the disc against the flywheel which causes
the clutch assembly and transaxle input shaft to
turn at engine speed.
With the pull-type clutch, the release bearing is
mechanically connected to the clutch diaphragm
spring. Before removing the transaxle, the clutch
release bearing must be disengaged from the clutch
diaphragm spring.
The flywheel is a large steel disc bolted to the end
of the crankshaft. It is used to dampen engine
vibration from cylinder firing pulsations and acts
as one friction surface for the clutch disc to work
against. The flywheel also draws off heat from the
clutch disc.
The clutch cover assembly bolts to the flywheel
and rotates at engine speed. The diaphragm spring
is a large conically shaped spring that forces the
pressure plate against the clutch disc under enough
pressure to prevent the clutch from slipping under
full engine torque. The pressure plate is a machined
disc that bears on the clutch disc friction surface
when the clutch is engaged.
The clutch disc is comprised of a metal hub
splined to the input shaft of the transmission, and
a thin metal disc faced with friction material. Small
torsional springs connect the hub to the metal disc,
and help cushion clutch engagement for smoother
operation without chattering.
The release bearing, also called a “throw-out”
bearing, is a permanently lubricated and sealed
ball-type thrust bearing. The release fork forces
the release bearing against the release fingers to
disengage the clutch.
Used with Montero and Raider, a pilot bearing
mounts inside the crankshaft rear flange to support
the transmission input shaft. This added support
ensures that the clutch disc stays in proper
alignment with the pressure plate and flywheel.

The cable clutch control system provides a
mechanical link between the clutch pedal and the
clutch release lever. The system is designed to
provide a mechanical advantage to decrease pedal
effort disengaging the clutch. As the clutch pedal
is depressed, the pedal pivots on the support shaft,
and pulls the inner clutch cable toward the rear of
the vehicle. Since the cable connects to the clutch
release lever mounted in the bell housing, the lever
and fork rotate forward, releasing the clutch. The
cable sheath is held stationary by a cable bracket on
the transmission. As the clutch pedal is released,
a return spring pulls the lever and the release fork
to the rear. When the release lever moves, it pulls
the inner cable toward the transaxle. This pulls the
clutch pedal back until it contacts a stop bolt. The
stop bolt is adjustable and establishes clutch pedal
height. Models with One-touch Start System (OSS)
and cruise control have a switch attached to the
stop bolt to indicate when the clutch is disengaged.
The clutch cable connects to the release lever shaft
which pivots the release fork. Two roll pins, or spring
pins, secure the release fork to the release lever
shaft. Acoil spring returns the clutch to its engaged
position when the driver lets up on the clutch pedal.
The Starter Interlock Switch prevents starting the
engine unless the clutch pedal is depressed. This
prevents the vehicle from lurching forward if clutch
is engaged with the transaxle in gear. A second
interlock switch signals the ECM to disengage
cruise control operation when the clutch pedal is
depressed.
Typically Pedal Height and Free Play are two
adjustments are possible on vehicles equipped with
cable operated clutch controls.
Hydraulic clutch controls form a link between the
clutch pedal and the clutch release lever to operate
the clutch. The hydraulic system automatically
compensates for clutch system wear, making
periodic adjustments unnecessary. When the
clutch pedal is depressed, the master cylinder
forces hydraulic fluid through an aluminum line and
rubber hose to the release (slave) cylinder.

21.00A
The release cylinder moves the clutch release
lever to release the clutch. As the clutch pedal
is released, diaphragm spring pressure forces the
release fork back, which in turn causes the slave
cylinder piston to force fluid back to the master
cylinder. Since the hydraulic lines are kept full of
fluid, this automatically compensates for worn clutch
components. This feature makes periodic free play
adjustments unnecessary.
The master cylinder consists of the cylinder body,
piston, pushrod, and a fluid reservoir. The pushrod
connects directly to the clutch pedal with a clevis
pin. As the clutch pedal is depressed, the pushrod
forces the piston down the cylinder bore. This forces
hydraulic fluid out of the cylinder bore under great
pressure to operate the slave cylinder.
The slave cylinder also consists of a cylinder body,
piston and push rod. Hydraulic fluid under pressure
from the master cylinder enters the cylinder behind
the piston. This forces the piston and pushrod out.
The pushrod connects to the clutch release lever,
and disengages the clutch. The Concentric Slave
Cylinder (CSC) is designed to operate directly on
the clutch diaphragm and eliminates the release
fork, pivot, and externally-mounted slave cylinder.
Mounted inside the bell housing and surrounding
the input shaft, the hydraulic cylinder presses
the incorporated release bearing against the
diaphragm to disengage the clutch. An adapter is
used to lengthen the fluid supply tube. The system
automatically compensates for wear, making
periodic adjustments unnecessary.
Hydraulic fluid must meet DOT 3 or DOT 4
specifications. This fluid does not compress when
the clutch pedal is depressed.

Page 12
Page 12
Page 16
Page 17
Page 8
Answerthefollowingquestionstoreviewthematerial
from this section. If you don’t know the answer, look
it up. If you answer a question incorrectly, read
the material covering the topic again until you fully
understand the information.
1. When the engine is idling and the clutch is
disengaged (pedal down), the
a. clutch disc turns with the flywheel.
b. release bearing is under load and spinning.
c. release bearing is not spinning.
d. flywheel does not spin.
2. The clutch cover assembly bolts to the:
a. crankshaft
b. flywheel
c. clutch disc
d. bellhousing
3. The clutch disc is forced against the flywheel by:
a. release bearing
b. diaphragm springs
c. clutch pedal
d. both a and b are correct
4. The pilot bearing is used in:
a. FWD transaxles to support the clutch end of
the input shaft.
b. FWD transaxles to keep the clutch centered.
c. RWD transmissions to center the flywheel.
d. RWD transmissions to support the front end
of the input shaft.
5. The cable in a cable operated clutch control
system:
a. pulls the pedal up when the driver releases
the clutch.
b. operates the clutch release lever.
c. is not adjustable.
d. None of the above
6. Which of the following is a benefit of the pull-
type clutch?
a. less pedal effort
b. can be used with a higher spring tension
c. less moving parts.
d. both a and b
KNOWLEDGE CHECK
Feedback

Pages 13
Page 26
Page 19
Page 10
21.00A
7. Which of these methods best describes how to
disengage the clutch release bearing from the
clutch diaphragm spring with a pull-type clutch?
a. Remove the clutch fork, then slide the
bearing toward the transaxle.
b. Use a flat-tip screwdriver inserted between
the bearing housing and the wedge collar.
c. Use snap ring pliers to remove the lock ring.
d. Use a release bearing remover/installer.
8. The clutch component subjected to the
highest wear is normally the:
a. pressure plate.
b. flywheel.
c. clutch disc.
d. torsional springs.
9. The hydraulic fluid used in hydraulically
controlled clutches should be:
a. mineral oil.
b. specially formulated for clutches only.
c. DOT 3 hydraulic brake fluid.
d. None of the above
10. The starter interlock switch is used to:
a. establish correct clutch pedal height equal
to the brake pedal height.
b. prevent starting the engine unless the clutch
is engaged (pedal up).
c. prevent starting the engine unless the clutch
is disengaged (pedal down).
d. compensate for differences when a new
master cylinder is installed.

NOTES

22.01A
TECHNICAL TRAINING
Instructor Guide
Gears, Bearings,
and Synchronizers
Section Description
This section explains basic gear and bearing fundamentals and
introduces synchronizer assemblies which allow a transmission/
transaxle to shift smoothly without gear clash.
Theory Section
22.01A

Gears, Bearings, and Synchronizers22.01A
NOTE
CAUTION
method.
WARNING
Note
Caution
!

Gears, Bearings, and Synchronizers
22.01A
Table of Contents
Section Introduction
Section Goal ………………………………………………………………...…… 3
Section Objectives ………………………………………………………………. 3
Needed Materials ……………………………………………………………….. 3
Time to Complete ……………………………………………………………….. 3
Overview ..……….………………….……………………………………………….…… 4
Gear Fundamentals ……………………………………………………………………. 4
Torque Multiplication …………………..……………………………………..… 5
Underdrive ……………………………………………………………………….. 6
Direct Drive …………………………………….……………………………...… 6
Overdrive ………………………………………………………………………… 7
Reverse ……..……………………………….………….……………………….. 8
Gear Types …………………………………………………………….……...… 9
Helical Gears …….…..……………………………….…………………. 9
Straight-Cut Spur Gears …………………………...…………………… 10
Sub Gears ……………………………………………………………….. 10
Bearing Fundamentals …………………………………………………………………. 13
Radial and Axial (Thrust) Loads ………………………………………………. 13
Ball Bearings ……………………………………………………………………. 14
Cylindrical (Parallel) Roller Bearings …………………………………………. 15
Needle Bearings ………………………………………………………………… 16
Roller Thrust Bearings ………………………………………………………….. 16
Tapered Roller Bearings ……………………………………………………….. 17
Total End Play …………………………………………………………………... 18
Bearing Preload …………………………………………………………………. 19
Bearing Service …………………………………………………………………. 20
Bearing Cleaning ……………………………………………………………….. 21
Ball and Cylindrical Roller Bearing Inspection ………….…………………… 22
Tapered Roller Bearing Inspection …………………………………………… 23
Bearing Installation ……………………………………………………………… 24
Bearing Race Installation ………………………………………………………. 24
Synchronizers …………………………………………………………………………… 25
Synchronizer Assembly Components
Hub ……………………………………………………………………….. 26
Single-Cone Synchronizer (Blocker) Ring ………………...…………. 27
Double-Cone Synchronizer ……………………………………………. 28
Free-Spinning Gears with One-Way Clutch Teeth Chamfering …… 29
Synchronizer Sleeve ……………………………………………………. 29
Synchronizer Keys and Springs ………………………………………. 31
Synchronizer Operation ………………………………………………… 32
Transaxle Diagnosis ……………………………………………………………………. 33
Lubricants and Additives ………………………………………………………………. 34
Section Summary ……………………………………………………………………….. 36
Knowledge Review Questions ………………………………………………………… 39

SECTION GOAL
SECTION OBJECTIVES After completing this section, you will be able to
perform the following tasks.
• Identify the gear ratio of any two gears
• Identify gear ratios providing torque
multiplication or speed increase
• Identify the component that reverses shaft
rotation
• Describe gears cut to reduce noise
• Describe gears cut to slide in and out of mesh
• Describe sub gears used to reduce a knocking
noises.
• Identify bearings used to support radial loads
• identify bearings used to support axial and
radial loads
• Describe the purpose of “preload” and “end
play” adjustments
• Identify where to press or pull when removing
or installing a bearing
• Describe how synchronizers ensure smooth
shifting without gear clash
• Describe transaxle diagnosis steps
• Identify the transmission/transaxle lubricants
required
NEEDED MATERIALS
TIME TO COMPLETE
Section 22.01A only.
About 20 minutes
Slide 22.01A-3
Slide 22.01A-3
This section explains basic gear and bearing
fundamentals and introduces synchronizer
assemblies which allow a transmission/
transaxle to shift smoothly without gear clash.

22.01A
OVERVIEW
Slide 22.01A-4a
Slide 22.01A-4b
Mitsubishi uses several manual transaxles to fit
the needs of different vehicles. All share the same
basic fundamentals, components, and terminology.
Technicians must possess a clear understanding of
how gears work, how bearings are used, and how
synchronizers operate to be able to diagnose and
repair manual transaxle and differential concerns.
GEAR FUNDAMENTALS
Torque Defined
Torque is the turning effort or energy used to turn
the gears, shafts and wheels. It is not the same as
power. The engine produces torque, but it is not
alwayssufficienttomovethevehicle,especially from
a complete stop. The purpose of the transmission
is to allow the driver to multiply engine torque when
additional torque is required.

In this rear wheel drive example, the crankshaft
transfers torque from the engine to the transmission
through the clutch. The driver selects a gear to
transfer the appropriate amount of torque to the
driveshaft. Torque is split by the differential and
applied to the wheels to make them rotate. Torque
is finally applied to the road to move the vehicle.
Gear sets can be used to multiply torque and
decrease speed, increase speed and decrease
torque, transfer torque and leave the speed the
same, or change the direction of torque.
Slide 22.01A-5a
Torque Multiplication
Slide 22.01A-5b
Gears of different sizes are used to provide several
gear ratios, or speeds, in the transmission. When
a small gear drives a larger gear, the larger gear
turns slower than the smaller gear, but it turns with
greater torque. Notice that there is always a trade-
off between torque and speed.

22.01A
In the illustration, the gear ratio is 2 to 1. Torque
applied to the larger gear will be twice the torque
applied to the smaller gear, but the larger gear
will turn at one-half the speed of the smaller gear.
Known as underdrive, a smaller gear drives a larger
gear to multiply torque. The drive gear speed is
higher than the driven gear speed in any underdrive
range. Examples of underdrive used with 5-speed
transaxle are 1st, 2nd, 3rd gears.
Slide 22.01A-6a
2 1
Drive Gear - 12 Teeth
Driven Gear - 24 Teeth
24 / 12 = 2 2:1 Ratio
Speed
Torque
Underdrive
Direct Drive
1 1
Driven Gear
12 Teeth
Drive Gear
12 Teeth
Speed
Torque
12 / 12 = 1 1:1 Ratio
Slide 22.01A-6b
When both gears are the same size, the gear ratio
is 1 to 1. Both gears turn at the same speed, and
there is no torque multiplication. The same torque
applied to one gear is available at the other gear.
This is often called direct drive because the speed
and torque applied to the drive gear transfers
directly to the driven gear with no change. 4th gear,
used in a 5-speed transaxle, is an example of 1:1.

A transmission contains several sets of gears that
provide different gear ratios the driver can select at
any time. The driver actually selects a set of gears
with the right gear ratio to get the desired amount of
torque multiplication.
For example, more torque is required for a vehicle
to travel uphill than to travel on a level road. The
driver selects a set of gears in the transmission
with a high gear ratio such as 3 to 1. For every
three engine revolutions, the output gear in the
transmission would rotate just once. This provides
three times the engine torque to travel uphill, but at
one-third the speed.
On a level road, less torque is required to move the
vehicle. The driver might also want the vehicle to
go faster. The driver selects a set of gears in the
transmission with a lower gear ratio. The lower gear
ratio provides less torque, but at a higher speed.
Overdrive
Drive Gear Driven Gear
1
0.5
24 Teeth 12 Teeth
12 / 24 = 0.5 0.5:1 Ratio
Speed
Torque
A gear ratio in 5th gear is usually less than 1. This
means the drive gear is larger than the driven gear.
For example, the drive gear might have 24 teeth
and the driven gear 12 teeth. The gear ratio is
24/12 = 0.5. With this gear set, is reduced instead
of multiplied, but speed is increased. An example of
overdrive used with 5-speed transaxle is 5th gear.
Slide 22.01A-7a

Instructor Note:
Only one idler gear is discussed here to
change direction. The W5M6A includes
six gears to make reverse and is covered
later in the course.
22.01A
Calculating Gear Ratios Gear ratio is calculated by dividing the number of
teeth on the driven gear by the number of teeth
on the drive gear. If the driven gear has 30 teeth
and the drive gear has 10 teeth, then the ratio is
3 to 1. To be completely accurate, this should be
expressed as 3:1.
Quite often the gear ratio is a decimal number. For
example, in 1st gear, the drive gear might have 23
teeth while the driven gear has 72 teeth. The gear
ratio would be 72/23 = 3.13. With this gear set,
torque would be multiplied 3.13 times, but speed
would be reduced 3.13 times.
A gear ratio in 5th gear is usually less than 1. This
means that the drive gear is larger than the driven
gear. For example, the drive gear might have 24
teeth and the driven gear 18 teeth. The gear ratio
is 18/24 = 0.75. With this gear set, torque would be
reduced instead of multiplied, but speed would be
increased.
Reverse
11
2
Drive Gear Idler Gear Driven Gear
Speed
Torque
For reverse, the driven gear needs to turn in the
same direction as the drive gear. To obtain reverse,
an idler gear is used to change the direction of the
driven gear. The drive gear is also smaller than
the driven gear to increase torque. The number of
idler gear teeth do not need to match the drive gear
teeth count.
Slide 22.01A-8a

Slide 22.01A-9a
Helical Gear
Spur Gear
Helical-cut gear teeth are cut on an angle. When
two helical gear teeth mesh, there is a small point of
contact near the ends of the two teeth. As the gears
rotate, the point of contact slides along the teeth to
the other end of the gear teeth. Before the point of
contact reaches the end, two more teeth come in
contact so that there is constant contact between
the two gears. This greatly reduces gear noise
because there is no “slapping” between gear teeth
as they mesh. This wiping action also distributes
lubricants evenly across the gear teeth. Because
they are quieter, helical gears are used for forward
gears in manual transmissions that are in constant
mesh. They are also used in some transmissions
for reverse.
Helical gears tend to slide sideways on their shaft,
so they are usually held firmly in place by a snap
ring or thrust washer.
Helical Gears
The 5-speed transaxle (F5MBB) used in a 2014
Outlander Sport is assembled with the ratios found
in the table below.
• 1st 3.833
• 2nd 1.913
• 3rd 1.333
• 4th 1.028
• 5th 0.820
Gear spacing is the distance between two adjacent
ratios. Notice the difference between 1st
and 2nd
(3.833 - 1.913 = 1.92) is greater than the difference
between 4th
and 5th
(1.028 - 0.820 = 0.208). This
arrangement provides easier starts and greater
acceleration in lower gears where it’s most needed.
Gear Spacing

22.01A
Straight-Cut Spur Gears
Spur gears have teeth cut straight across the
outside diameter of the gear and tend to produce
more noise than helical-cut gears. This is because
the full width of the driven gear tooth tends to “slap”
the tooth it contacts on the drive gear producing a
“growl” during operation.
Spur gears are usually used for reverse and the
noise is considered to be tolerable in most vehicles.
Also, since non-synchronized reverse gears are not
constantly meshed, the straight-cut design makes it
easier to slide the gears in and out of mesh.
Helical Gear
Spur Gear
Slide 22.01A-10a
Spur Bevel Gears
Slide 22.01A-10b
A spur bevel gear rotates on an axis 90 degrees
offset from the gear in which it contacts. These are
most typically used as pinion and side gears in a
differential assembly.

3rd Speed
Gear
Synchro Ring
Synchro
Spring
3-4 Synchro Sleeve
3-4 Synchro Hub
Synchro
Spring
Synchro Ring
Bearing Sleeve
Needle Bearing
4th Gear
Belleville
Sub Gear
Cone Spring
Snap Ring
Spacer
Ball Bearing
Bearing Sleeve
Slide 22.01A-11a
The Belleville sub gear (as shown in the drawing
above from a F5M31 transaxle) takes up all
rotational play between two shafts with a thin sub
gear pressed against the main gear by a cone-type
Belleville spring. The sub gear has one more tooth
than the main gear next to it, and takes up the slack
between the main gear and the gear with which it
normally meshes. As the shaft turns, the sub-gear
slowly “walks around” the main gear.
Cone Spring
Snap Ring
Sub Gear
4th
Gear
Belleville Sub Gear
Sub Gears Some older Mitsubishi transaxles use sub gears to
quiet knocking noises caused by backlash between
two gears.
• Belleville Sub Gear
• Spring Pre-loaded Sub Gear

22.01A
A Spring Preloaded Sub Gear (used in the KM163
transaxle, for example) has the same number of
teeth as the main gear. The sub gear is spring loaded
against the gear which meshes with the main gear.
This maintains constant contact between these two
gears and takes up any rotational play between the
shafts. During assembly, the sub gear and spring
are usually wound up to provide the correct amount
of spring preload.
Spring Preloaded Sub Gear
Spring
Sub Gear
Locating Holes
Tapered Roller
Bearing
Spacer
Intermediate Gear
Slide 22.01A-12a

BEARING FUNDAMENTALS
Slide 22.01A-13a
Radial Load
Radial Load
Axial
(Thrust)
Load
Axial
(Thrust)
Load
Bearings provide either a sliding or a rolling
contact whenever relative motion exists between
rotating parts. Sliding contact bearings (crankshaft
support, for example) are known as plain bearings
while rolling contact bearings (like those used in a
transaxle) are often called anti-friction bearings.
Bearings are designed to support a shaft against
radial loads or axial (thrust) loads while allowing
the shaft to rotate freely.
Radial loads are those applied perpendicular to the
shaft while axial loads are those applied parallel to
the shaft.
Radial and Axial (Thrust) Loads

22.01A
Slide 22.01A-14a
These bearings can handle both radial and thrust
loads and may be an open construction design
(as shown above) or permanently lubricated and
sealed.
Ball Bearings
Two races contain the balls and transmit the loads
through the balls. One race is stationary and the
other is attached to the rotating component. As
one of the bearing races rotates it causes the balls
to rotate as well. The load is transmitted from the
outer race to the ball to the inner race. The ball
only contacts the inner and outer race at a very
small point which helps it spin very smoothly. It also
means there is little contact area holding the load.
In applications where ball bearings are used,
bearing end play must be adjusted, typically with
shims located behind the bearing.
Outer Diameter
Shield (or Seal)
Cage
Face
Inner Race
Ball
Shoulder
Outer Race
Slide 22.01A-14b

Cylindrical (Parallel) Roller Bearings
Slide 22.01A-15a
This bearing type uses rollers which run parallel to
the shaft they support. The rollers have a greater
contact area with the outer race and distribute loads
across a broader surface. Subsequently, they have
relatively high radial load capabilities but limited
thrust load capacity.
Some cylindrical roller bearings are manufactured
with snap ring grooves on their outer rings to retain
the bearing in the transaxle case.
Slide 22.01A-15c
Cylindrical roller bearings are typically used to
support input shafts in light duty applications such
as the F5MBB transaxle.
Slide 22.01A-15b

22.01A
Slide 22.01A-16a
Needle bearings are compact cylindrical roller
bearings.Thesearecommonlyusedintransmissions
to support free-spinning gears where radial loads
occur, but space is limited. In some cases, these
bearings are split into two halves to make installation
easier on a shaft with several different diameters.
Cages can either be constructed of plastic or metal.
Needle Bearings
Roller thrust bearings support large axial loads.
They are often found between gears in gearsets,
and between the housing and the rotating shafts.
Roller Thrust Bearings
Slide 22.01A-16b

Tapered Roller Bearings
Slide 22.01A-17a
Tapered roller bearings are designed to handle both
radial and axial loads and consist of the cone (inner
ring), cup (outer ring), tapered rollers, and cage
(roller retainer). The cone, cup and rollers carry the
load while the cage spaces and retains the rollers
on the cone. The bearing cage assembly and inner
race form a non-separable unit.
These bearings commonly support shafts with
helical gears which generate large thrust loads and
are pre-loaded during assembly to limit sideways
movement and end play. Preload is controlled with
a selective shim placed behind the outer bearing
race. When the transaxle case halves are bolted
together, the amount of preload exerted depends
on the thickness of the shim. The thicker the shim,
the more pressure exerted.
Slide 22.01A-17b
Because of the high thrust loads, tapered roller
bearings are typically used to support an output
shaft (F5MBB transaxle shown above). In high
performance applications such as the W5M6A
(Lancer Evolution) tapered roller bearings are used
to support the input shaft.

22.01A
Total End Play
Slide 22.01A-18a
In operation, an aluminum transaxle case expands at
a different rate than the shafts, gears, and bearings.
Since a bearing’s outer race is held stationary in the
case, it moves away from the inner race as heat
increases. Mounted to the shafts, the position of
the inner race remains stationary. This forward and
rearward travel is called end play.
Total end play measures the amount of free play not
only in the bearing but also in the transaxle gear
train.
Insufficient end play causes pressure (preload) on
the bearings resulting in premature wear. Some end
play is also required for lubrication. If the end play
is excessive, the gear train may suffer from impact
damage, possible harsh shifting, or noise.
Total end play is set by measuring the shaft’s total
travel and is adjusted using selective thickness
shims to ensure the correct clearance exists. This
prevents difficult shifts, abnormal noises, premature
bearing wear, or popping out of gear.
When a shaft is supported with ball or cylindrical
roller bearings, end play is set. These bearings are
not preloaded.
Depending on the transaxle, various methods of
measuring end play are used to select the proper
shim dimension. These will be discussed in the Skill
sections of this course.

Bearing Preload
Selective Shim
Outer Bearing Race
Slide 22.01A-19a
Preloading is a method of controlling internal
bearing clearances which affect noise, vibration,
heat build-up, and overall bearing life. Preloaded
tapered roller bearings provide more accurate shaft
guidance because preload restricts the ability of
the shaft to deflect under load. For example, the
rotational accuracy and the increased stiffness from
preloaded output shaft and differential bearings
allows the gear mesh to remain constant with quiet
operation and long service life.
Excessive preload can cause increased bearing
heat which reduces shaft speed and bearing life. It
also increases the power needed to drive the shaft.
Too little preload causes the shaft to move with
consequent damage to the bearing seat, excessive
wear, noise, vibration, and reduced rotational
accuracy.
With manual transaxle shafts and differential
assemblies, preload is achieved by using a properly
sized shim between the case and an outer bearing
race to obtain the required preload.
As with end play, various methods of measuring
preload are used to select the proper shim
dimension. These will be discussed in the Skill
sections of this course.

22.01A
Bearing Service
If in good condition and removed with care, bearings
are usually reusable. To prevent damage to bearings
or other components during removal or installation,
follow the precautions listed below.
• Ensure a clean work area and tools
• Use correct tools, equipment, and procedures
specified in Mitsubishi service manual Group 22B
• After cleaning and inspection, protect reusable
bearings from dirt and moisture
• Keep new bearings packaged until ready to use
• Never reuse a bearing where force has been
applied through the rollers or balls.
• Always replace a bearing and associated races
as a set. Never use a new bearing with an old
race or vice versa.
Slide 22.01A-20a
MB992039
MB990211
MD998368
MD998917
Bearing Removal Race Removal

Bearing Cleaning
Bearings can be cleaned with kerosene, mineral
spirits, or solvent. Use the cleaning solution to
remove all lubricant and contamination, making
sure that the internal rolling elements are completely
clean.
After the bearing has been cleaned, it can be dried
with compressed air. Never allow a bearing to
spin when drying it with compressed air. The
bearing may disintegrate damaging the bearing
and possibly causing serious injury.
After cleaning, the bearing should be thoroughly
inspected for damage and signs of wear.
The inspection area must be clean and free from
dirt and debris to avoid contaminating the bearing.
Even a small piece of debris that enters a bearing
can create a stress point leading early fatigue.
The bearing should be covered with a coating of
light oil if it is not going to be returned to service
immediately.
!
Slide 22.01A-21a

Instructor Note:
In the photo at right, the ball, inner
race, and outer race all show signs of
wear.
22.01A
To inspect a ball or cylindrical roller bearing, hold
it horizontally by the inner race, and turn the outer
race slowly by hand. There should be no play in any
direction. The bearing should turn smoothly with
no roughness or other signs of wear or damage.
Discoloration of any kind usually means the bearing
has been overheated. Closely inspect the inner
and outer races as well as the balls and rollers for
damage or wear.
Ball and Cylindrical Roller
Bearing Inspection
Slide 22.01A-22a

Tapered Roller Bearing Inspection
Slide 22.01A-23a
Inspect a tapered roller bearing and race in the
same way as a ball or cylindrical roller bearing.
Look closely at the bearing cage. Damage to the
cage usually indicates too little preload. Damage
to the large end of the rollers or heat discoloration
usually indicates excessive preload. Look closely
at the bearing races for signs of wear or damage.
Along with examining bearings, a close inspection
should include the transaxle case and shafts. Check
for burrs or metal chips on the outer bearing race
seats. These can usually be removed by carefully
scraping or filing the damaged surfaces. Inspect
the shaft for proper size, roundness, burrs or other
damage.
Inspection of Related Components
Bearing Installation
Slide 22.01A-23b
MIT304180-A
MD998820
Inner Race
Tool
Shaft
When installing a bearing onto a shaft, use the
specified special tool with an inner diameter slightly
larger than the outer diameter of the shaft.

22.01A
The outer diameter of the tool should be small
enough so it doesn’t contact the rolling elements or
bearing cage.
Position the tool on the inner race and apply steady
pressure with sufficient force to smoothly press the
race into place.
It is good practice to coat the shaft with light oil to
reduce the force needed to press the bearing on
the shaft.
Bearing Race Installation
Slide 22.01A-24a
The same principal applies to installing the outer
race as those for the bearing itself. Use a tool large
enough to fully contact the outer edge of the race
but small enough to clear the case bore.
MB991966
Tool
Bearing Race Transaxle Case
Snap Rings
Snap rings are used to retain gears, bearings, or
other components on shafts. Often snap rings are
select fit to control end play or preload.
To enable snap ring pliers to be used, always install
with beveled edge down toward the component.
Slide 22.01A-24b

SYNCHRONIZERS
Slide 22.01A-25a
Free-Spinning
Gear
Free-Spinning
Gear
Synchronizer
Sleeve
Shift Rail
Shift Fork
Input or
Output Shaft
The synchronizers allow smooth shifting without
gear clash. Most synchronizers control two speeds.
For example, one synchronizer would control shifts
between 1st and 2nd, another would handle 3rd
and 4th, and another would handle 5th/Reverse in
5-speed transmissions.
On each side of a typical Synchronizer assembly,
there are two Free-Spinning gears each associated
with one of the two gears the synchronizer controls.
The purpose of the synchronizer is to select one
gear or the other by locking one of the free-spinning
gears to its shaft smoothly without grinding or
mechanical shock.
The shaft (either the input or output) and drive gear
spins at one speed while the Free-Spinning gear
turns at a different speed (if not stationary). The
synchronizer must match the speed of free-spinning
gear and its shaft before locking them together or a
rough shift will result. When neither gear as been
selected, the synchronizer is set in a neutral position
so that neither free-spinning gear is locked to the
shaft.

22.01A
Synchronizer Assembly Components
Synchronizer Hub
Slide 22.01A-26a
Synchronizer
Hub
The Synchronizer Hub is splined to the shaft on
which it is installed. Most hubs are held in place
on the shaft by the adjacent free-spinning gears
that they control. There may be a dimple in the oil
groove or a beveled edge to indicate the correct
installation direction.
When installing a hub and sleeve, verify the correct
installation direction found in service manual Group
22B. Improper orientation can cause a hard shift or
pop out of gear.
Hub Oil Groove
Sleeve
Notch
Slide 22.01A-26b
Beveled
Edge
Hub Oil Groove

Instructor Note:
Alloys: silicon bronze, aluminum bronze,
or manganese bronze
Two types of synchronizer cones are used in
Mitsubishi transaxles. Some are single cone designs
where the steel cone on the free-spinning gear
contacts the surface of the blocker ring. (F5MBB
4th gear shown above)
Slide 22.01A-27b
Single-Cone Synchronizer
Synchronizer (Blocker) Rings
Synchronizer Rings (Blocker Rings) have a cone-
shaped friction surface on one side and gear teeth
on the other. The ring mates with the Free-Spinning
gear’s machined surface called the cone. The ring
“blocks” the synchronizer sleeve from moving until
the speeds of the drive gear, synchro hub, and free-
spinning gear are matched. Rings can be made of
brass, bronze, or a sintered material.
An indication of synchronizer ring wear or damage
can be seen by inspecting the transaxle’s gear lube
for yellow-colored particles.
Slide 22.01A-27a

22.01A
In some transaxles, the surface of the blocker ring
is lined with a sintered bronze or paper material to
provide better synchronization.
Slide 22.01A-28a
Slide 22.01A-28b
To reduce shift effort when controlling large gears
like 1st and 2nd, a Double-Cone Synchronizer is
used. Two synchronizer rings are combined with a
separate steel cone (lugged to the gear). Used in
place of one blocker ring, this design increases the
effective frictional surface area.
Double-Cone Synchronizer
3rd Gear, F5MBB Reverse Gear, W5M6A
The cone surfaces are machined with thread or
groove patterns and axial slots which are spaced
around the inner circumference. This machining
allows for quicker oil displacement from between
the cone surfaces and causes the free-spinning
gear speed to increase faster.

Slide 22.01A-29b
Synchronizer Sleeve
Synchronizer
Sleeve
Shift Rail
and Fork
Moved in one direction or the other by a shift rail
and fork, the Synchronizer Sleeve slides over the
hub, blocker ring teeth, and the free-spinning gear’s
engagement teeth.
Free-Spinning Gears with
One-Way Clutch Teeth Chamfering
Shown above is 1st gear (conventional) and 2nd
gear (one-way) used in the F5MBB transaxle.
Clutch teeth leading edges (mesh points) are often
chamfered to improve shift feel with 2nd, 3rd, and
4th free-spinning gears. This “one-way flow” design
allows making shifts without interfering with the
gear’s rotation. With a conventional shape, as the
clutch gear and sleeve start to mesh, the sleeve
attempts to push the clutch gear in the opposite
direction. The clutch gear pushes back against the
synchronizer and resistance to the shift is felt. To
reduce resistance, the chamfered portions of 2nd,
3rd, and 4th clutch gears can be a one-way design.
Slide 22.01A-29a
Conventional
Chamfer Shape
One-Way
Chamfer Shape

22.01A
Slide 22.01A-30a
As used with both F5MBB and F5MBD transaxles,
reverse gear teeth are cut into the outer
circumference of the 1-2 Synchronizer Sleeve.
1-2 Synchronizer Sleeve
and Reverse Free-Spinning Gear
When shifted to Reverse, the Reverse Shift Arm
moves the Reverse Idler into mesh with Reverse
Drive gear and Reverse Free-Spinning gear.
Slide 22.01A-30b

Some transaxles employ a keyless synchronizer
design which uses springs instead of a keys.
Sleeve
Hub
Synchro Spring (A)
Synchro Spring (B)
5th Free-Spinning Gear
Blocker Assembly
Keyless Synchronizer
Slide 22.01A-31b
Slide 22.01A-31a
Synchronizer Keys and Springs
Three synchronizer keys lock the sleeve to the
blocker ring when the sleeve moves toward the
free-spinning gear. A pair of circular wire springs
positioned around the inner circumference of
the sleeve (or coil springs under the key) press
outward against the keys, holding them in place
in the sleeve. During a shift, this spring tension is
overcome, which adds to the driver’s shift effort.
Not all keys used in Mitsubishi transaxles are
identical. Some are symmetrical at both ends,
and may be installed in any direction. Others have
different ends, and must be installed only one way.
Group 22B notes these differences and provides
correct installation information.
Key

Instructor Note:
Play Synchronizer Operation.avi video.
22.01A
Slide 22.01A-32a
Synchronizer Operation
Free
Spinning
Gear
Free
Spinning
Gear
Synchronizer
Sleeve
Shift Rail
and Fork
To shift the transaxle into 1st gear, the clutch pedal
is depressed and the gearshift lever is placed in
1st gear position, forcing the shift fork and sleeve
toward 1st free-spinning gear. As the sleeve moves,
the keys also move because the insert ridges lock
the inserts to the internal groove of the sleeve.
The movement of the inserts forces the blocker
ring’s coned friction surface against 1st gear’s
coned friction surface. The grooves on the blocker
ring cone cut through the lubricant film on the 1st
gear’s cone and a metal-to-metal contact is made.
As the components reach the same speed, the
sleeve slides over the external blocking ring teeth
and then over 1st gear’s engagement (clutch) teeth
completing the engagement. Power flow is now
from 1st free-spinning gear, to the sleeve, to the
hub, to the output shaft, and out to final drive.
Although the process is the same for upshift and
downshift, time needed to complete a shift is
different. During an upshift, the gear’s revolution
speed decreases and less shift time is required.
However during a downshift, the gear is forced to
accelerate thus increasing shift time.

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