John Deere Tractor 6820, 6920 and 6920S Repair Manual TM4756 - PDF File

Tractors
6820, 6920 and
6920S
Repair
TECHNICAL MANUAL
Tractors 6820, 6920 and 6920S
Repair
TM4756 01SEP01 (ENGLISCH)
For complete service information also see:
Tractors 6020 to 6920S
OperationandTests...................TM4741
Tractors 6020 to 6920S
Diagnostics..........................TM4726
Front Wheel Drive Axles . . . . . . . . . . . . . . . . CTM4687
POWERTECH Diesel Engines . . . . . . . . . . . CTM104
Mechanical Fuel Injection Systems . . . . . . . CTM207
Electronic Fuel Injection Systems . . . . . . . . CTM170
Alternators and starter motors. . . . . . . . . . . CTM77
John Deere Werke Mannheim
European Edition
Printed in Germany

Introduction
TM4643,00004F0 –19–01OCT01–1/1
Foreword
TM4756 (01SEP01)
This repair manual is valid for the following tractor
types:
6820, 6920 and 6920S.
The manual is written for experienced customer
service personnel. Essential tools required in
performing certain service work are identified in this
manual and are recommended for use.
Live with safety: Read the safety messages in the
introduction of this manual and the cautions presented
throughout the text of the manual.
This is the safety-alert symbol. It indicates that
there is danger of injury.
Technical Manuals are concise service guides for
specific machines. They are on-the-job guides
containing only the vital information needed for
diagnosis, analysis, testing, and repair.
Fundamental service information is available from
other sources covering basic theory of operation,
fundamentals of troubleshooting, general maintenance,
and basic type of failures and their causes.
051002
PN=2

Contents
Continued on next page
PN=1
05
10
20
30
40
53
55
56
60
70
TM4756 (01SEP01)
SECTION 05—Safety
Group 05—Safety information
SECTION 10—General information
Group 05—Specifications
Group 10—Tune-up
Group 15—Inspection before delivery
SECTION 20—Engine
Group 00—Installing and removing components
SECTION 30—Fuel, air intake, heating, exhaust
system
Group 05—Speed control
Group 10—Fuel system
Group 15—Air intake system
Group 20—Heating system
Group 25—Cold-weather starting aid
Group 30—Exhaust system
SECTION 40—Electrical equipment
Group 05—Electrical connectors
Group 10—Wiring harnesses
Group 15—Charging current circuit
Group 20—Starting current circuit
Group 25—Fuses, relays and connectors
Group 30—Monitoring systems
Group 40—Electrical components
SECTION 53—AutoPowr/IVT transmission
Group 00—Removing and installing the
AutoPowr/IVT transmission
Group 05—Transmission shifting mechanisms
Group 10—Input housing
Group 15—Output housing
Group 20—Assembling the intermediate shaft
SECTION 55—PowrQuad, PowrQuad Plus and
AutoQuad transmission
Group 05—Transmission shifting mechanisms
Group 10—PowrQuad module
Group 15—Creeper transmission
Group 20—Range transmission
SECTION 56—Transmission (without gear)
Group 05—U.J. Shaft and torsion damper
Group 10—FWD clutch
Group 15—Differential
Group 20—Hydraulic pump drive
Group 25—Final drives
Group 30—Rear PTO
SECTION 60—Steering and brakes
Group 05—Hydrostatic steering
Group 10—Brake valve
Group 15—Rear wheel brakes
Group 20—Handbrake
Group 25—Hydraulic trailer brakes
Group 30—Air brake system
SECTION 70—Hydraulic system
Group 05—Control elements
Group 10—Hydraulic pump and charge oil pump
Group 15—Valves
Group 20—Rockshaft
Group 25—Additional control units and reception
couplings
Group 30—Indepent additional control unit
SECTION 80—Miscellaneous
Group 05—Main frame
Group 10—Front and rear wheels
Group 15—Trailer support and counterweight
pendant
Group 20—Axle suspension of TLS front wheel
drive axle
Group 25—Hydraulic wagon hitch
SECTION 90—Operator’s cab
Group 05—Controls and instruments
Group 10—Air-conditioning system
Group 15—Heating system
Group 20—Seats
051002
All information, illustrations and specifications in this manual are based on
the latest information available at the time of publication. The right is
reserved to make changes at any time without notice.
COPYRIGHT  2001
DEERE & COMPANY
European Office Mannheim
All rights reserved
A John Deere ILLUSTRUCTION Manual
i

Contents
05
10
20
30
40
53
55
56
60
70
PN=2
TM4756 (01SEP01)
Group 25—Operator’s cab
Group 30—Components of the electronic hitch
control
SECTION 99—Special tools (dealer- fabricated)
Group 05—Special tools (dealer- fabricated)
051002
ii

Page
PN=1
05
Section 05
Safety
Contents
TM4756 (01SEP01)
Group 05—Safety information
Recognize Safety Information . . . . . . . . . . . . . .05-05-1
“Important” - Information . . . . . . . . . . . . . . . . . .05-05-1
“Note” - Information. . . . . . . . . . . . . . . . . . . . . .05-05-1
Prevent Machine Runaway . . . . . . . . . . . . . . . .05-05-1
Handle Fluids Safely—Avoid Fires . . . . . . . . . .05-05-2
Prevent Battery Explosions . . . . . . . . . . . . . . . .05-05-2
Prepare for Emergencies. . . . . . . . . . . . . . . . . .05-05-2
PreventAcidBurns......................05-05-3 Avoid High-
Pressure Fluids . . . . . . . . . . . . . . . .05-05-4 Service
Cooling System Safely . . . . . . . . . . . . .05-05-4 Remove
Paint Before Welding or Heating . . . . .05-05-5 Avoid
Heating Near Pressurized Fluid Lines . . .05-05-5 Work
In Ventilated Area . . . . . . . . . . . . . . . . . .05-05-6 Wear
Protective Clothing. . . . . . . . . . . . . . . . . .05-05-6 Practice
Safe Maintenance . . . . . . . . . . . . . . . .05-05-7
ParkMachineSafely.....................05-05-7 Use Proper
Lifting Equipment . . . . . . . . . . . . . .05-05-8 Construct
Dealer-Made Tools Safely . . . . . . . . .05-05-8 Support
Machine Properly. . . . . . . . . . . . . . . . .05-05-8
WorkinCleanArea......................05-05-9 Illuminate Work
Area Safely . . . . . . . . . . . . . . .05-05-9 Service Machines
Safely . . . . . . . . . . . . . . . . . .05-05-9
UseProperTools......................05-05-10 Service Tires
Safely . . . . . . . . . . . . . . . . . . . .05-05-10 Service Front-
Wheel Drive Tractor Safely . . . .05-05-11 Working on the
Air Brake System . . . . . . . . . .05-05-11 Avoid Eye
Contact With Radar . . . . . . . . . . . .05-05-12 Keep ROPS
Installed Properly . . . . . . . . . . . .05-05-12 Replace Safety
Signs . . . . . . . . . . . . . . . . . . .05-05-12 Dispose of Waste
Properly . . . . . . . . . . . . . . .05-05-13
LiveWithSafety.......................05-05-13 Safety Measures
for Electronic Control
Units..............................05-05-14
051002
05-1

Contents
05
PN=2
TM4756 (01SEP01) Tractors 6820, 6920 and 6920S
051002
05-2

05-05-1
Group 05
Safety information
PN=7
0
5
0
5
1
DX,ALERT
LX,CRA05 002885
LX,CRA05 002886
DX,BYPAS1
–19–09APR92–1/1
–19–09APR92–1/1
–19–29SEP98–1/1
–19–29SEP98–1/1
“Note” - Information
“Important” - Information
Prevent Machine Runaway
Recognize Safety Information
T81389
–UN–07DEC88
TS177
–UN–11JAN89
TM4756 (01SEP01)
Information designated as IMPORTANT points out
possible problems that might lead to damage to the
machines. These problems can be avoided by heeding
the appropriate information.
Avoid possible injury or death from machinery runaway.
Do not start engine by shorting across starter terminals.
Machine will start in gear if normal circuitry is bypassed.
NEVER start engine while standing on ground. Start
engine only from operator’s seat, with transmission in
neutral or park.
This is a safety-alert symbol. When you see this symbol
on your machine or in this manual, be alert to the
potential for personal injury.
Follow recommended precautions and safe operating
practices.
Information designated as NOTE contains further details
or restrictions relevant to the preceding instructions.
However, it can also be useful information that pertains to
the instructions, but is not directly relevant to it.
051002

Safety information
0
5
0
5
2
PN=8
DX,SPARKS
DX,FIRE2
DX,FLAME –19–29SEP98–1/1
–19–03MAR93–1/1
–19–03MAR93–1/1
Prepare for Emergencies
Prevent Battery Explosions
Handle Fluids Safely—Avoid Fires
TS227
–UN–23AUG88
TS204
–UN–23AUG88
TS291
–UN–23AUG88
TM4756 (01SEP01)
Keep sparks, lighted matches, and open flame away from
the top of battery. Battery gas can explode.
Never check battery charge by placing a metal object
across the posts. Use a volt-meter or hydrometer.
Do not charge a frozen battery; it may explode. Warm
battery to 16°C (60°F).
When you work around fuel, do not smoke or work near
heaters or other fire hazards.
Store flammable fluids away from fire hazards. Do not
incinerate or puncture pressurized containers.
Make sure machine is clean of trash, grease, and debris.
Do not store oily rags; they can ignite and burn
spontaneously.
Be prepared if a fire starts.
Keep a first aid kit and fire extinguisher handy.
Keep emergency numbers for doctors, ambulance service,
hospital, and fire department near your telephone.
051002
05-05-2

Safety information
PN=9
0
5
0
5
3
DX,POISON –19–21APR93–1/1
Prevent Acid Burns
TS203
–UN–23AUG88
TM4756 (01SEP01)
Sulfuric acid in battery electrolyte is poisonous. It is strong
enough to burn skin, eat holes in clothing, and cause
blindness if splashed into eyes.
Avoid the hazard by:
1. Filling batteries in a well-ventilated area.
2. Wearing eye protection and rubber gloves.
3. Avoiding breathing fumes when electrolyte is added.
4. Avoiding spilling or dripping electrolyte.
5. Use proper jump start procedure.
If you spill acid on yourself:
1. Flush your skin with water.
2. Apply baking soda or lime to help neutralize the acid.
3. Flush your eyes with water for 15—30 minutes. Get
medical attention immediately.
If acid is swallowed:
1. Do not induce vomiting.
2. Drink large amounts of water or milk, but do not
exceed 2 L (2 quarts).
3. Get medical attention immediately.
051002
05-05-3

Safety information
0
5
0
5
4
PN=10
DX,RCAP
DX,FLUID –19–03MAR93–1/1
–19–04JUN90–1/1
Avoid High-Pressure Fluids
Service Cooling System Safely
X9811
–UN–23AUG88
TS281
–UN–23AUG88
TM4756 (01SEP01)
Explosive release of fluids from pressurized cooling
system can cause serious burns.
Shut off engine. Only remove filler cap when cool enough
to touch with bare hands. Slowly loosen cap to first stop
to relieve pressure before removing completely.
Escaping fluid under pressure can penetrate the skin
causing serious injury.
Avoid the hazard by relieving pressure before
disconnecting hydraulic or other lines. Tighten all
connections before applying pressure.
Search for leaks with a piece of cardboard. Protect hands
and body from high pressure fluids.
If an accident occurs, see a doctor immediately. Any fluid
injected into the skin must be surgically removed within a
few hours or gangrene may result. Doctors unfamiliar with
this type of injury should reference a knowledgeable
medical source. Such information is available from Deere &
Company Medical Department in Moline, Illinois, U.S.A.
051002
05-05-4

Safety information
PN=11
0
5
0
5
5
DX,PAINT –19–19JUL01–1/1
DX,TORCH –19–03MAR93–1/1
Remove Paint Before Welding or Heating
Avoid Heating Near Pressurized Fluid Lines
TS220
–UN–23AUG88
TS953
–UN–15MAY90
TM4756 (01SEP01)
Flammable spray can be generated by heating near
pressurized fluid lines, resulting in severe burns to
yourself and bystanders. Do not heat by welding,
soldering, or using a torch near pressurized fluid lines or
other flammable materials. Pressurized lines can be
accidentally cut when heat goes beyond the immediate
flame area.
Avoid potentially toxic fumes and dust.
Hazardous fumes can be generated when paint is heated
by welding, soldering, or using a torch.
Remove paint before heating:
• Remove paint a minimum of 76 mm (3 in.) from area to
be affected by heating.
• If you sand or grind paint, avoid breathing the dust.
Wear an approved respirator.
• If you use solvent or paint stripper, remove stripper with
soap and water before welding. Remove solvent or
paint stripper containers and other flammable material
from area. Allow fumes to disperse at least 15 minutes
before welding or heating.
Do not use a chlorinated solvent in areas where welding
will take place.
Do all work in an area that is well ventilated to carry toxic
fumes and dust away.
Dispose of paint and solvent properly.
051002
05-05-5

Safety information
0
5
0
5
6
PN=12
DX,AIR –19–17FEB99–1/1
DX,WEAR –19–10SEP90–1/1
Work In Ventilated Area
Wear Protective Clothing
TS220
–UN–23AUG88
TS206
–UN–23AUG88
TM4756 (01SEP01)
Wear close fitting clothing and safety equipment
appropriate to the job.
Prolonged exposure to loud noise can cause impairment
or loss of hearing.
Wear a suitable hearing protective device such as
earmuffs or earplugs to protect against objectionable or
uncomfortable loud noises.
Operating equipment safely requires the full attention of
the operator. Do not wear radio or music headphones
while operating machine.
Engine exhaust fumes can cause sickness or death. If it is
necessary to run an engine in an enclosed area, remove
the exhaust fumes from the area with an exhaust pipe
extension.
If you do not have an exhaust pipe extension, open the
doors and get outside air into the area
051002
05-05-6

Safety information
PN=13
0
5
0
5
7
DX,SERV
DX,PARK –19–04JUN90–1/1
–19–17FEB99–1/1
Park Machine Safely
Practice Safe Maintenance
TS218
–UN–23AUG88
TS230
–UN–24MAY89
TM4756 (01SEP01)
Before working on the machine:
Lower all equipment to the ground.
Stop the engine and remove the key.
Disconnect the battery ground strap.
Hang a "DO NOT OPERATE" tag in operator station.
Understand service procedure before doing work. Keep
area clean and dry.
Never lubricate, service, or adjust machine while it is
moving. Keep hands, feet , and clothing from
power-driven parts. Disengage all power and operate
controls to relieve pressure. Lower equipment to the
ground. Stop the engine. Remove the key. Allow machine
to cool.
Securely support any machine elements that must be
raised for service work.
Keep all parts in good condition and properly installed. Fix
damage immediately. Replace worn or broken parts.
Remove any buildup of grease, oil, or debris.
On self-propelled equipment, disconnect battery ground
cable (-) before making adjustments on electrical systems
or welding on machine.
On towed implements, disconnect wiring harnesses from
tractor before servicing electrical system components or
welding on machine.
051002
•
•
•
•
05-05-7

Safety information
0
5
0
5
8
PN=14
DX,SAFE,TOOLS
DX,LIFT
DX,LOWER –19–24FEB00–1/1
–19–04JUN90–1/1
–19–10OCT97–1/1
Support Machine Properly
Use Proper Lifting Equipment
Construct Dealer-Made Tools Safely
LX1016749
–UN–01JUL97
TS226
–UN–23AUG88
TS229
–UN–23AUG88
TM4756 (01SEP01)
Lifting heavy components incorrectly can cause severe
injury or machine damage.
Follow recommended procedure for removal and
installation of components in the manual.
Faulty or broken tools can result in serious injury. When
constructing tools, use proper, quality materials, and good
workmanship.
Do not weld tools unless you have the proper equipment
and experience to perform the job.
Always lower the attachment or implement to the ground
before you work on the machine. If the work requires that
the machine or attachment be lifted, provide secure
support for them. If left in a raised position, hydraulically
supported devices can settle or leak down.
Do not support the machine on cinder blocks, hollow tiles,
or props that may crumble under continuous load. Do not
work under a machine that is supported solely by a jack.
Follow recommended procedures in this manual.
When implements or attachments are used with a
machine, always follow safety precautions listed in the
implement or attachment operator’s manual.
051002
05-05-8

Safety information
PN=15
0
5
0
5
9
DX,LOOSE
DX,LIGHT –19–04JUN90–1/1
–19–04JUN90–1/1
DX,CLEAN –19–04JUN90–1/1
Work in Clean Area
Service Machines Safely
Illuminate Work Area Safely
TS223
–UN–23AUG88
TS228
–UN–23AUG88
T6642EJ
–UN–18OCT88
TM4756 (01SEP01)
Tie long hair behind your head. Do not wear a necktie,
scarf, loose clothing, or necklace when you work near
machine tools or moving parts. If these items were to get
caught, severe injury could result.
Remove rings and other jewelry to prevent electrical
shorts and entanglement in moving parts.
Illuminate your work area adequately but safely. Use a
portable safety light for working inside or under the
machine. Make sure the bulb is enclosed by a wire cage.
The hot filament of an accidentally broken bulb can ignite
spilled fuel or oil.
Before starting a job:
• Clean work area and machine.
• Make sure you have all necessary tools to do your job. •
Have the right parts on hand.
• Read all instructions thoroughly; do not attempt
shortcuts.
051002
05-05-9

Safety information
0
5
0
5
1
0
PN=16
DX,RIM –19–24AUG90–1/1
DX,REPAIR –19–17FEB99–1/1
Use Proper Tools
Service Tires Safely
TS779
–UN–08NOV89
TS211
–UN–23AUG88
TM4756 (01SEP01)
Use tools appropriate to the work. Makeshift tools and
procedures can create safety hazards.
Use power tools only to loosen threaded parts and
fasteners.
For loosening and tightening hardware, use the correct
size tools. DO NOT use U.S. measurement tools on
metric fasteners. Avoid bodily injury caused by slipping
wrenches.
Use only service parts meeting John Deere specifications.
Explosive separation of a tire and rim parts can cause
serious injury or death.
Do not attempt to mount a tire unless you have the proper
equipment and experience to perform the job.
Always maintain the correct tire pressure. Do not inflate
the tires above the recommended pressure. Never weld or
heat a wheel and tire assembly. The heat can cause an
increase in air pressure resulting in a tire explosion.
Welding can structurally weaken or deform the wheel.
When inflating tires, use a clip-on chuck and extension hose
long enough to allow you to stand to one side and NOT in
front of or over the tire assembly. Use a safety cage if
available.
Check wheels for low pressure, cuts, bubbles, damaged
rims or missing lug bolts and nuts.
051002
05-05-10

Safety information
PN=17
0
5
0
5
1
1
LX,AIRBRAKES
LX,MFWD2
–19–03MAR94–1/1
–19–01MAY91–1/1
Working on the Air Brake System
Service Front-Wheel Drive Tractor Safely
LX008009
–UN–24APR96
L124515
–UN–06AUG94
TM4756 (01SEP01)
When servicing front-wheel drive tractor with the rear
wheels supported off the ground and rotating wheels by
engine power, always support front wheels in a similar
manner. Loss of electrical power or transmission/
hydraulic system pressure will engage the front driving
wheels, pulling the rear wheels off the support if front
wheels are not raised. Under these conditions, front drive
wheels can engage even with switch in disengaged
position.
CAUTION: The compressed air tank of the air
brake system is under pressure!
Before work is performed on the air brake system, all
pressure must be released from the system. Never do any
welding on the air brake system.
051002
05-05-11

Safety information
0
5
0
5
1
2
PN=18
DX,ROPS3
RX,SAFTY,RADAR1
DX,SIGNS1 –19–04JUN90–1/1
–19–03MAR93–1/1
–19–21SEP92–1/1
Replace Safety Signs
Keep ROPS Installed Properly
Avoid Eye Contact With Radar
TS266
–UN–23AUG88
TS212
–UN–23AUG88
TS201
–UN–23AUG88
TM4756 (01SEP01)
Replace missing or damaged safety signs. See the
machine operator’s manual for correct safety sign
placement.
Radar ground speed sensor emits a very low intensity
microwave signal. It will not cause any ill effects during
normal use. Although intensity is low, DO NOT look
directly into face of sensor while in operation, to avoid any
possible eye damage.
Make certain all parts are reinstalled correctly if the
roll-over protective structure (ROPS) is loosened or
removed for any reason. Tighten mounting bolts to proper
torque.
The protection offered by ROPS will be impaired if ROPS
is subjected to structural damage, is involved in an
overturn incident, or is in any way altered by welding,
bending, drilling, or cutting. A damaged ROPS should be
replaced, not reused.
051002
05-05-12

Safety information
PN=19
0
5
0
5
1
3
DX,LIVE
DX,DRAIN –19–03MAR93–1/1
–19–25SEP92–1/1
Live With Safety
Dispose of Waste Properly
TS1133
–UN–26NOV90
TS231
–19–07OCT88
TM4756 (01SEP01)
Before returning machine to customer, make sure
machine is functioning properly, especially the safety
systems. Install all guards and shields.
Improperly disposing of waste can threaten the
environment and ecology. Potentially harmful waste used
with John Deere equipment include such items as oil, fuel,
coolant, brake fluid, filters, and batteries.
Use leakproof containers when draining fluids. Do not use
food or beverage containers that may mislead someone
into drinking from them.
Do not pour waste onto the ground, down a drain, or into
any water source.
Air conditioning refrigerants escaping into the air can
damage the Earth’s atmosphere. Government regulations
may require a certified air conditioning service center to
recover and recycle used air conditioning refrigerants.
Inquire on the proper way to recycle or dispose of waste
from your local environmental or recycling center, or from
your John Deere dealer.
051002
05-05-13

Safety information
0
5
0
5
1
4
PN=20
LX25599,0000243 –19–01JAN01–1/1
Safety Measures for Electronic Control Units
TM4756 (01SEP01)
CAUTION: Always shut off the engine and
set the key switch to “OFF” before
connecting test equipment to the tractor.
CAUTION: Always engage the parking lock
when performing tests with the engine
running.
CAUTION: When testing is performed with
the engine running, there is a risk of injury
from rotating parts.
IMPORTANT: Do not use test lamps on any control
unit. Only use a multimeter
(JT05791A).
IMPORTANT: To protect electronic circuits,
disconnect the battery and alternator
before performing any welding on
the tractor.
051002
05-05-14

Section 10
General information 10
Contents
Page
Continued on next page
Page
PN=1
Group 05—Specifications
Technical data (summary of references) . . . . . .10-05-1
Engine specifications. . . . . . . . . . . . . . . . . . . . .10-05-2
Coolingcircuit..........................10-05-3
Injection pump (Bosch VP44) . . . . . . . . . . . . . .10-05-3
AirIntakeSystem.......................10-05-3
Electricalsystem........................10-05-3
Hydrostatic Steering System . . . . . . . . . . . . . . .10-05-4
Clutch................................10-05-4
AutoPowr/IVT transmission . . . . . . . . . . . . . . . .10-05-4
PowrQuad Plus transmission. . . . . . . . . . . . . . .10-05-5
AutoQuad II transmission . . . . . . . . . . . . . . . . .10-05-5
Creeper transmission . . . . . . . . . . . . . . . . . . . .10-05-5
RearPTO.............................10-05-6
FrontPTO.............................10-05-6
Differential assembly . . . . . . . . . . . . . . . . . . . . .10-05-6
Differentiallock.........................10-05-6
Finaldrives............................10-05-7
FrontWheelDrive.......................10-05-7
FWDAxlewithTLS......................10-05-7
HydraulicBrakes........................10-05-7
Handbrake............................10-05-8
ParkingLock...........................10-05-8
Hydraulic System with Axial Piston Pump . . . . .10-05-8
Rockshaft.............................10-05-8
FrontHitch............................10-05-9
GroundSpeeds.........................10-05-9
FrontandRearWheels...................10-05-9
Dimensions and Weights. . . . . . . . . . . . . . . . . .10-05-9
Capacity specifications . . . . . . . . . . . . . . . . . .10-05-10
Handling and Storing Diesel Fuel . . . . . . . . . .10-05-11
DieselFuel...........................10-05-12
Lubricity of Diesel Fuel . . . . . . . . . . . . . . . . . .10-05-13
Diesel Engine Break-In Oil . . . . . . . . . . . . . . .10-05-13
DieselEngineOil......................10-05-14
Transmission and Hydraulic Oil. . . . . . . . . . . .10-05-15
Front Wheel Drive Axle Oil . . . . . . . . . . . . . . .10-05-16
Diesel Engine Coolant. . . . . . . . . . . . . . . . . . .10-05-17
Supplemental Coolant Additives . . . . . . . . . . .10-05-18
Grease..............................10-05-19
OilFilters.............................10-05-19
Mixing of Lubricants . . . . . . . . . . . . . . . . . . . .10-05-20
LubricantStorage......................10-05-20
Operating in Warm Temperature Climates . . .10-05-21
Alternative and Synthetic Lubricants . . . . . . . .10-05-21
TM4756 (01SEP01)
Unified Inch Bolt and Cap Screw Torque
Values.............................10-05-22
Metric Bolt and Cap Screw Torque Values . . .10-05-23
Hydraulic system inch fitting torques . . . . . . . .10-05-24
Hydraulic system metric fitting torques . . . . . .10-05-25
Product identification and component serial
numbers...........................10-05-26
Engine serial number . . . . . . . . . . . . . . . . . . .10-05-27
Transmission serial number . . . . . . . . . . . . . .10-05-27
Front wheel drive axle serial number. . . . . . . .10-05-27
Operator’s cab serial number . . . . . . . . . . . . .10-05-27
Sub-assembly serial numbers . . . . . . . . . . . . .10-05-28
Group 10—Tune-up
Tune-up (summary of references) . . . . . . . . . . .10-10-1
Repair specifications . . . . . . . . . . . . . . . . . . . . .10-10-1
Using High-Pressure Washers . . . . . . . . . . . . .10-10-2
Preliminary engine test . . . . . . . . . . . . . . . . . . .10-10-2
Tractortune-up.........................10-10-3
Removing and Cleaning the Primary Air
CleanerElement......................10-10-4
Checking the Air Cleaner Safety Element . . . . .10-10-4
Installing the Primary Filter Element . . . . . . . . .10-10-4
Checking the Air Intake System Connections
forLeaks............................10-10-5
Checking the Crankcase Vent Hose for
Clogging............................10-10-5
Cleaning the Radiator Grille Screen . . . . . . . . .10-10-5
Keeping the Radiator Screen Clean . . . . . . . . .10-10-5
Checking the Caps on the Expansion Tank . . .10-10-6
Checking the Radiator for Leaks . . . . . . . . . . . .10-10-6
Checking the engine’s thermostat . . . . . . . . . . .10-10-6
Checking the fuel transfer pump operation . . . .10-10-7
Bleeding the Fuel System (Tractors
Equipped with Bosch VP44 Injection
Pump)..............................10-10-8
Checking the fuel filter (with Bosch VP44
injectionpump)......................10-10-11
Cleaning the water trap. . . . . . . . . . . . . . . . . .10-10-11
Run the engine until it is warm, and check
enginespeeds......................10-10-12
Check setting of fuel injection pump . . . . . . . .10-10-12
Cleaning the Battery, Cables and Battery
Box with a Clean Cloth . . . . . . . . . . . . . . . .10-10-13
051002
10-1

Contents
10
Page
PN=2
TM4756 (01SEP01)
Checking the neutral start circuit . . . . . . . . . . .10-10-13
Checking operation of starter motor . . . . . . . .10-10-14
Checking the lighting circuit. . . . . . . . . . . . . . .10-10-14
Final Engine Check. . . . . . . . . . . . . . . . . . . . .10-10-14
Tractor Operation Check . . . . . . . . . . . . . . . . .10-10-15
Group 15—Inspection before delivery
Predelivery Inspection . . . . . . . . . . . . . . . . . . . .10-15-1
051002
10-2

10-05-1
Group 05
Specifications
PN=23
1
0
0
5
1
LX25458,00000F8 –19–18JAN02–1/1
Technical data (summary of references)
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TM4756 (01SEP01)
“Engine specifications”
“Cooling system”
“Injection pump (Bosch VP44)”
“Air intake system”
“Electrical system”
“Hydrostatic steering”
“Clutch operation”
”AutoPowr/IVT transmission”
“PowrQuad Plus transmission”
“AutoQuad II transmission”
“Creeper transmission
“Rear PTO”
”Front PTO”
“Differential assembly”
“Differential lock”
“Final drives”
“Front wheel drive”
“FWD axle with TLS”
“Hydraulic brakes”
“Handbrake”
“Park lock”
“Hydraulic system with axial piston pump”
“Hitch”
”Front hitch”
“Ground speed”
“Front and rear wheels”
“Dimensions and weights”
“Capacity specifications”
“Handling and storing diesel fuel”
“Diesel fuel”
“Lubricity of diesel fuel”
“Diesel engine break-in oil”
“Diesel engine oil”
“Transmission and hydraulic oil”
“FWD axle oil”
“Diesel engine coolant”
“Supplemental coolant additives”
“Grease”
“Oil filter”
“Mixing of lubricants”
“Lubricant storage”
“Operating in warm temperature climates”
“Alternative and synthetic lubricants”
“Unified inch bolt and cap screw torque values”
“Metric bolt and cap screw torque values”
“Hydraulic system inch fitting torques”
“Hydraulic system metric fitting torques”
“Product identification and component serial
numbers”
“Engine serial number”
“Transmission serial number”
“FWD axle serial number”
“Operator’s cab serial number”
“Subassembly serial numbers”
051002

Specifications
1
0
0
5
2
Type
- 6820 ............................................................................................................................................................................ 6068HLA71 (Turbocharger) - 6920
............................................................................................................................................................................ 6068HLA72 (Turbocharger) - 6920S
......................................................................................................................................................................... 6068HLA73 (Turbocharger)
Engine power according to ECE-R24 at rated engine speed
with Visco fan
-6820...............................................................................................................................................................................................99kW(135hp)
-6920.............................................................................................................................................................................................110kW(150hp)
-6920S..........................................................................................................................................................................................118kW(160hp)
Max. torque (at 1500 rpm)
-6820..........................................................................................................................................................................................611N•m(450lb-ft)
-6920..........................................................................................................................................................................................699N•m(515lb-ft)
-6920S.......................................................................................................................................................................................699N•m(515lb-ft)
Max. PTO power at rated PTO speed (factory measured, with 1000 rpm at PTO)
-6820...............................................................................................................................................................................................90kW(122hp)
-6920...............................................................................................................................................................................................99kW(134hp) - 6920S
Whendriving..................................................................................................................................................................................104kW(141hp) When
tractor is stationary .............................................................................................................................................................. 100 kW (136 hp)
Bore...........................................................................................................................................................................................106.5mm(4.19in.)
Stroke........................................................................................................................................................................................127.0mm(5.00in.)
Displacement ......................................................................................................................................................................... 6790 cm3 (414 cu.in.)
Firingorder.............................................................................................................................................................................................1-5-3-6-2-4
Compressionratio.........................................................................................................................................................................................16.8:1
Valve clearance (engine hot or cold)
- Intake valves ........................................................................................................................................................................... 0.35 mm (0.014 in.) -
Exhaust valves ........................................................................................................................................................................ 0.45 mm (0.018 in.)
Slow idle:
- Electronic actuation at an ambient temperature:
Above 20°C (68°F) ................................................................................................................................................................................ 850±10 rpm
Between 0°C (32°F) and 20°C (68°F) .................................................................................................................................................. 875±50 rpm
Below0°C(32°F).................................................................................................................................................................................1050±10rpm
Fast idle
- Electronic actuation ..................................................................................................................................................................... 2250-10/+20 rpm With
AutoQuad activated .................................................................................................................................................................. 2100 rpm max.
Rated engine speed ................................................................................................................................................................................. 2100 rpm
Operating speeds ................................................................................................................................................................. 1300 rpm - 2100 rpm
PN=24
LX25458,00000FF –19–22JAN02–1/1
Engine specifications
051002
10-05-2

Specifications
Engine air cleaner ............................................................ dry-type air cleaner, self-cleaned by pressure from the fan blade; with safety element
Type ................................................. solenoid valve-controlled radial piston distributor pump, regulated electronically and giving direct injection
Numberofpistons..............................................................................................................................................................................................four Injection
pressure ..................................................................................................................................... approx. 700 bar (70000 kPa; 10150 psi)
Automaticswitchingoff...............................................................................................................................................................................electrical
Type .......................................................................................................... pressurized cooling system with centrifugal pump and expansion tank
Temperature control ............................................................................................................................................. thermostat and viscous fan drive
Battery ....................................................................................................................................................................... 12 V, 154 Ah or 12 V, 174 Ah
Alternator with overvoltage protection ............................................................................................................................ 14 V, 90 A or 14 V, 115 A Starter
motor ........................................................................................................................................................................... 12 V, 3.0 kW (4.0 hp)
Batteryterminalgrounded...........................................................................................................................................................................negative
PN=25
1
0
0
5
3
AG,LX25458,151
LX25458,0000094
AG,LX25458,324
LX25458,00000F9
–19–13JUN00–1/1
–19–07DEC99–1/1
–19–22JAN02–1/1
–19–18OCT01–1/1
Cooling circuit
Electrical system
Air Intake System
Injection pump (Bosch VP44)
051002
10-05-3

Specifications
1
0
0
5
4
Type.....................................................................................................................................................................................................fullyhydraulic
Type ............................................................................................................................................................. hydraulically controlled wet disk clutch
Operation .................................................................................................................... mechanical / hydraulic with pre-tensioned Belleville springs
Type ........................................................................................................................................ infinitely variable mechanical/hydraulic transmission
Forward/reverse speed range ................................................................................................................. 0.1 km/h (0.06 mph)—40 km/h (25 mph)
Forward/reverse speed range ................................................................................................................ 0.1 km/h (0.06 mph)—50 km/h (31 mph)a
Shifting the reverse drive lever ...................................................................................................... electrical, under load, without operating clutch
Shiftingthespeedcontrollever..................................................................................................................................................................................
................... increases and decreases in speed are infinitely variable and take place without interrupting the power flow or actuating the clutch
a
If equipped
PN=26
AG,LX25458,155
AG,LX25458,156
AG,LX25458,322 –19–10JUN00–1/1
–19–06DEC99–1/1
–19–06DEC99–1/1
Clutch
AutoPowr/IVT transmission
Hydrostatic Steering System
051002
10-05-4

Specifications
Type ................................................................................................................................................................ synchronized hydraulic transmission Range
shifting ............................................................................................................................................................... mechanically, synchronized -Tractors with
40 km/h (25 mph) transmission ......................................................................................................................................... 5 ranges Shifting of the 4 gears
........................................................................................... mechanical/hydraulic, under load, without actuating the clutch Reverse gear shifting
............................................................................................. mechanical/hydraulic, under load, without actuating the clutch Shifting the F-N-R lever
............................................................ mechanical-hydraulic or electrical-hydraulic, under load, without operating clutch
Type ................................................................................................................................................................ synchronized hydraulic transmission
Range shifting ............................................................................................................................................................... mechanically, synchronized
-Tractors with 40 km/h (25 mph) transmission ......................................................................................................................................... 5 ranges -
Tracors with 50 km/h (31 mph) transmission .......................................................................................................................................... 5 ranges
Shifting of the 4 gears ..................................................................................................... electrical-hydraulic, under load, without operating clutch
Reverse gear shifting ....................................................................................................... electrical-hydraulic, under load, without operating clutch
Shifting the F-N-R lever ............................................................ mechanical-hydraulic or electrical-hydraulic, under load, without operating clutch
Type ...................................................................................................................................................................... non-synchronized reduction gear
Reduction of ground speed in ranges A, B and C as well as in the reverse range .......................................................................... approx. 90 % Shifting
the two creeper speeds ........................................................................................................................... mechanically, non-synchronized
PN=27
1
0
0
5
5
LX25458,00000FA
LX25458,00000FB
–19–22JAN02–1/1
–19–22JAN02–1/1
LX25458,00000FC –19–22JAN02–1/1
Creeper transmission
AutoQuad II transmission
PowrQuad Plus transmission
051002
10-05-5

Specifications
1
0
0
5
6
Type ............................................................................................................................................... independent, engaging/disengaging under load Engine
speed for PTO operation
- 540 rpm rear PTO (reversible or shiftable) ............................................................................................................................................. 1995 rpm - 540E
rpm rear PTO ................................................................................................................................................................................. 1743 rpm - 1000 rpm
rear PTO ................................................................................................................................................................................. 1995 rpm
Type ..................................................................................................................................................................... engaging/disengaging under load Engine
speed for 1000 rpm front PTO (viewed in direction of travel)
- clockwise rotating (6 splines) .................................................................................................................................................................. 1995 rpm -
counterclockwise rotating (21 splines) .................................................................................................................................................... 1995 rpm
Operation ........................................................................................................................................................... electrical/hydraulic, pedal operated
Disengaging ................................................................................................................................... electrical/hydraulic, after traction has equalized
Type.....................................................................................................................................................................................helicalbevelgeardrive
PN=28
AG,LX25458,164
AG,LX25458,165
AG,LX25458,248
AG,LX25458,249
–19–24JAN00–1/1
–19–24JAN00–1/1
–19–08DEC99–1/1
–19–08DEC99–1/1
Rear PTO
Front PTO
Differential lock
Differential assembly
051002
10-05-6

Specifications
Type ........................................................................... self-adjusting, hydraulically operated wet disk brakes, individually acting in field operation
Type...................................................................................................................................................................................planetaryreductiongear
Type ........................................................................................................................................................ active spring system with levelling control
Control................................................................................................................................................................................electro/hydro/pneumatic
Type .......................................................................................................................................... operated under load, hydraulically controlled drive with
wet disk clutch
Control................................................................................................................................................................solenoidvalve,electrical-hydraulic
Engagement ..................................................................................................................................................... with pre-tensioned Belleville springs
Disengagement......................................................................................................................................................................................hydraulically
PN=29
1
0
0
5
7
AG,LX25458,167
AG,LX25458,170
AG,LX25458,250
AG,LX25458,251
–19–24JAN00–1/1
–19–24JAN00–1/1
–19–08DEC99–1/1
–19–07DEC99–1/1
Final drives
Hydraulic Brakes
Front Wheel Drive
FWD Axle with TLS
051002
10-05-7

Specifications
1
0
0
5
8
Type ............................................................................................................ mechanically operated locking pawl, acting on front wheel drive gear
Type ................................................................................................................................. mechanically operated brake band acting on differential
Type ............................................................................................... three-point hitch with two lift cylinders, activated via stepper motor and valve
Control types ............................................................................................................................... load, depth, load-and depth control, float position
Control ................................................................................. electronic/hydraulic draft link control, draft sensor or position sensor (actual value),
..............................................................................................................................................................................operationbox(set-pointvalues),
............................................................................................................................................................................electroniccontrolunit(processor)
Type ............................................................................................................................................. closed-center system with Load-Sensing control
System pressure:
min. (stand-by) ............................................................................................................................................................... 3000 kPa (30 bar; 435 psi) max.
......................................................................................................................................................................... 20000 kPa (200 bar; 2900 psi) Pump type
.............................................................................................................................. axial piston pump, pressure- and flow-compensated
PN=30
AG,LX25458,171
AG,LX25458,172
AG,LX25458,173
AG,LX25458,175
–19–07DEC99–1/1
–19–07DEC99–1/1
–19–07DEC99–1/1
–19–07DEC99–1/1
Rockshaft
Handbrake
Parking Lock
Hydraulic System with Axial Piston Pump
051002
10-05-8

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John Deere Tractor 6820, 6920 and 6920S Repair Manual TM4756 - PDF File

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John Deere Tractor 6820, 6920 and 6920S Repair Manual TM4756 - PDF File