LEARNING LESSON

1. AUTOMOTIVE SERVICING
QUARTER 1 -WEEK 8
DIAGNOSING MANUAL
TRANSMISSION FAILURES
JUMAR A. BALDREZ
SUBJECT TEACHER

2. OBJECTIVES: After going through this lesson, you are
expected to……..
• LO 1. Diagnose manual transmission failure.
(TLE_IAAUS9-12OMT-Ia-b-43)
Sub-task:
1. Describe what is transmission.
2. Identfy the types of transmission.
3. Familiarize with the components of manual transmission.
4. Diagnose manual transmission failures.

3. 5 Min.
READING ACTIVITY

4. READING ACTIVITY
GEAR

5. READING ACTIVITY
CLUTCH

6. READING ACTIVITY
SPEED

7. READING ACTIVITY
SHAFTS

8. READING ACTIVITY
IDLER

9. READING ACTIVITY
SHIFT

10. READING ACTIVITY
REVERSE

11. READING ACTIVITY
ASSEMBLY

12. READING ACTIVITY
AUTOMATIC

13. READING ACTIVITY
TRANSMISSION

14. Direction:
Read each statement and select the best answer.
Pre- Test

15. 1. What component part of a power train unit that
transmits power coming from the engine to rear
wheels?
A. Differential C. Clutch
B. Transmission D. Drive line
B. Transmission

16. 2. What do we call the protruding part in the driver’s
compartment on top of the transmission used in
shifting the gears in the transmission?
A. Synchronizer C. Output shaft
B. Gear shift lever D. All of these
B. Gear shift lever

17. 3. Which of the following is a group of gears cast in a
piece with others assembled in the lower part of
the transmission housing?
A. Reverse gear C. Counter gear assembly
B. Idler gear D. None of these
C. Counter gear assembly

18. 4. Which of the following is meshed with the reverse
counter gear. It is kept into alignment by an idler
shaft?
A. Counter gear C. Reverse gear
B. Output shaft D. Idler gear
D. Idler gear

19. 5. What are different type of shafts found in the
transmission?
A. Input drive shaft with gear shaft
B. Counter shaft
C. main shaft or output
D. All of these
D. All of these

20. Groupings
Divide the class into two groups.
SCORING SYSTEM
A.Easy Round (10 points)
B. Average Round (30 points)
C. Difficult Round (50 points)
D.Extra Round (20 points)
Note: The group with a higher points earned will win a
prize

21. TEXT TWIST
DECIPHER THE JUMBLED WORDS
10 Points

22. TEXT TWIST
ERAG
GEAR

23. TEXT TWIST
EEPSD
SPEED

24. TEXT TWIST
SFHAT
SHAFT

25. TEXT TWIST
ERVSEER
REVERSE

26. TEXT TWIST
IRMNSASSTION
TRANSMISSION

27. TEXT TWIST
OYEZIRRNCNSH
SYNCHRONIZER

28. SOLVE ME
•Solve a mathematical equation (Find the value of X)
• Once the value of X is identified, get the equivalent
letter according to its order in the alphabet.
• The learners should present the correct word
created from the given mathematical equations.
30 Points

29. X X X X
1.) X+7=14 2.) 8-X=3
3.) X+6=7 4.) X-7=11
1.) 7= G
2.) 5= E
3.) 1= A
4.) 18= R

30. X X X X X X X
1.) X+15=33 2.) 6+X=11
3.) X+6=28 4.) X+11=16
5.) 9+X=27 6.) X+5=24
7.) 21+X=26
1.) 18= R
2.) 5= E
3.) 22= V
4.) 5= E
5.) 18= R
6.) 19= S
7.) 5= E

31. X X X X X X X
1.) 21-X=19 2.) 6-X=1
3.) 23-X=22 4.) X-11=7
5.) 17-X=8 6.) X-5=9
7.) X-2=5
1.) 2= B
2.) 5= E
3.) 1= A
4.) 18= R
5.) 9= I
6.) 14= N
7.) 7= G

32. X X X X X X
1.) X-7=6 2.) 8+X=9
3.) X+6=20 4.) X-7=14
5.) 14+X=15 6.) X-4=8
1.) 13= M
2.) 1= A
3.) 14= N
4.) 21= U
5.) 1= A
6.) 12= L

33. What is TRANSMISSION?
The transmission, also known as the
gearbox, transfers power from the engine.

34. What is TRANSMISSION?
The energy from the engine’s rotation
passes through the combination gears of
the transmission to the driveshaft.

35. What is TRANSMISSION?
The combination of gears inside the
transmission changes the rotary speed
and torque to become faster or slower.

36. What is TRANSMISSION?
The higher gears of the transmission
produce high speed while the lower gears
generate more power.

37. HOW
TRANSMISSION
WORKS?

39. Function of Transmission
1.Provide the torque needed to move the
vehicle under varying road and load conditions.
2.Be shifted into reverse so the vehicle can
move backward.
3.Be shifted into neutral for starting the engine
and running it without turning the drive
wheels.

40. WHAT ARE THE
TYPES OF
TRANSMISSION?

41. WHAT ARE THE TYPES OF
TRANSMISSION?
MANUAL TRANSMISSION
&
AUTOMOATIC TRANSMISSION

42. MANUAL TRANSMISSION

43. MANUAL TRANSMISSION
Allows the engine to transmit power from
the engine to the wheels via a series of gears.
Different gears determine the ratios between
the engine revolutions and the wheel
revolutions.

44. AUTOMATIC TRANSMISSION

45. AUTOMATIC TRANSMISSION
A transmission in which gear ratios are
changed or adopts to speed automatically
when the accelerator pedal is pressed.

46. MAIN COMPONENTS
OF
MANUAL
TRANSMISSION

48. TRANSMISSION FAILURES/
PROBLEMS AND DIAGNOSIS
Transmission and clutch troubles are
interrelated. When the driver complains of
hard shifting, the problem is not always in the
transmission. A clutch not properly adjusted
can cause this trouble.

49. TRANSMISSION FAILURES/ PROBLEMS AND DIAGNOSIS
TROUBLES POSSIBLE CAUSES REMEDIES
Hard
shifting
1. Burned out or distorted
transmission main shaft
2. Shifting mechanism out of
adjustment
3. Worn sliding gears
4. Worn out or bent shifting
5. Worn out or damaged
synchronizer assembly
6. Excessive tension of poppet
ball spring
1. Inspect and if found
defective, replace
2. Shift mechanism, check
and adjust Replace
3. Replace
4. Replace
5. Check springs tension
replace if not proper
6. Check springs tension
replace if not proper

50. TRANSMISSION FAILURES/ PROBLEMS AND DIAGNOSIS
TROUBLES POSSIBLE CAUSES REMEDIES
Slipping
out of
gears
1. Loose sliding gears main
shaft
2. Worn out sliding gears or
counter gear
3. Excessive end play of
counter gear assembly
4. Worn out bearings
5. Bent shifting fork used in
first and reverse
6. Weak or broken poppet ball
spring used in first and reverse
1. Inspect and if found
defective, replace
2. Shift mechanism, check
and adjust Replace
3. Replace
4. Replace
5. Check springs tension
replace if not proper
6. Check springs tension
replace if not proper

51. TRANSMISSION FAILURES/ PROBLEMS AND DIAGNOSIS
TROUBLES POSSIBLE CAUSES REMEDIES
Gears
return to
neutral
when
shifting
to 2nd or
1st
1. Worn out dog gear
2. Worn out synchronizing
blocks ring
3. Worn out or damaged
synchronizing hub or
sleeve
4. Worn out synchronizing
locks
5. Worn out shifting rails
6. Worn out or damaged
poppet balls
1. Replace
2. Replace
3. Replace
4. Replace
5. Replace
6. Replace

52. TRANSMISSION FAILURES/ PROBLEMS AND DIAGNOSIS
TROUBLES POSSIBLE CAUSES REMEDIES
Gears
return to
neutral
when
shifting
to 2nd or
1st
7. Excessive end play of
counter
8. Worn out bearings
9. Misalignment of engine
and transmission
10. Shifting linkages out of
adjustment
11. Excessive end play of
transmission main shaft.
7. Replace
8. Replace
9. Aligned engine
transmission
10. Check and adjust
11. Check and replace

53. TRANSMISSION FAILURES/ PROBLEMS AND DIAGNOSIS
TROUBLES POSSIBLE CAUSES REMEDIES
Transmis
sion
noisy
when
shifted
1. Defective clutch system
2. Worn out defective
transmission main shaft
bearing
3. Loose gears on
transmission main shaft
4. Worn out gears
5. Worn out speedometer
gear
6. Excessive end play of
transmission main shaft
1. Check and replace
2. Check and replace
3. Check and replace
4. Check and replace
5. Check and replace
6. Check and replace

54. TRANSMISSION FAILURES/ PROBLEMS AND DIAGNOSIS
TROUBLES POSSIBLE CAUSES REMEDIES
Gear oil
leaks on
transmis
sion
1. Damaged oil seal
2. Worn out gasket
3. Loose or missing cover
bolts
4. Oil level is to high
5. Oil slinger damaged or
improperly installed
6. Loose drain plugs
7. Loose transmission bearing
retainer bolts
1. Check and replace
2. Check and replace
3. Check and tighten
4. Check level
5. Check and replace
6. Check and tighten
7. Check and replace

55. TRANSMISSION FAILURES/ PROBLEMS AND DIAGNOSIS
TROUBLES POSSIBLE CAUSES REMEDIES
Trans
mission
sticks on
gears
1. Clutch is not operating
properly
2. Burred or buttered teeth on
synchronizing hub or sleeve
3. Lack of lubrication
4. Improper lubrication
5. Corroded shaft levers or shaft
6. Binding input shaft pilot
bearing
7. Frozen synchronizing block
ring on input shaft gear cover.
1. Check and replace
2. Check and replace
3. Check and lubricate
4. Check grade oil
5. Check and clean
6. Check and replace
7. Check and replace

56. Skills Relay (50 Pts)
•Identify the strength of its member/s.
A.Solving B. Vocabulary
C. Familiarization of transmission parts
• Solve the given math problem/s.
• Look for the box where their answer is written.
• Get one rolled paper with jumbled word
• Decipher the jumbled words.
• correctly pick-up and show the actual part/
component deciphered from the jumbled word.

57. 1.) 22+8x10

58. Answer
1.) 102
(INPUT SHAFT)

59. 2.) 25+4x3-22

60. Answer
2.) 15
(THIRD GEAR)

61. 3.) 28÷7+8x5

62. Answer
3.) 44
(SHIFT FORK)

63. 4.) 16x2+30÷6

64. Answer
4.) 37
(BELL HOUSING)

65. 5.) 82+6x3-20

66. Answer
5.) 80
(COUNTER SHAFT)

67. Trouble Shooting
(20 Pts)
•identify the possible causes/ remedies
of the following transmission troubles

68. TROUBLES POSSIBLE CAUSES REMEDIES
Trans
mission
sticks on
gears
Lack of lubrication
TROUBLES POSSIBLE CAUSES REMEDIES
Hard
shifting
Excessive tension of
poppet ball spring

69. TROUBLES POSSIBLE CAUSES REMEDIES
Gears
return to
neutral
when
shifting to
2nd or 1st
Misalignment of
engine and
transmission
TROUBLES POSSIBLE CAUSES REMEDIES
Transmissio
n noisy
when
shifted
Loose gears on
transmission main
shaft