Isuzu KB P190. Manual — part 1178

7B1-106 MANUAL TRANSMISSION

2) NOISY OPERATION

Checkpoint

Trouble

Cause

Countermeasure

Replenish or replace the gear

oil

Insufficient or improper engine

oil

NG

Replace the gear(s)

Replace the gear(s)

Replace the bearing(s)

Gears (Gear whining)

Lack of backlash between

meshing gears

Free running gears seizing on

the thrust face or the inner

face

Bearings (Hissing, thumping

or bumping)

Worn or broken bearing(s)

Gears (Squealing at high

speeds)

Replace the gear(s)

Gears (Growling, humming, or

grinding)

Worn, chipped, or cracked

gear(s)

NG

NG

NG

NG

OK

OK

OK

OK

Gear oil (Metallic rattling)

MANUAL TRANSMISSION 7B1-107

2. HARD SHIFTING

Checkpoint

Trouble

Cause

Countermeasure

Change lever play

Clutch pedal free play

Repair or replace the

applicable parts and regrease

Readjust the clutch pedal free

play

Worn change lever sliding

portions

Improper clutch pedal free

play

Change lever operation

Repair or regrease the change

lever assembly

Replenish or replace the

engine oil

Hard operating change lever

caused insufficient grease

Insufficient or improper gear

oil

OK

OK

NG

NG

NG

NG

OK

OK

Gear oil

Continued on the next page

Shift rod and quadrant box

sliding faces, and other parts

Replace the shidt rod and/or

the quadrant box

Worn shift rod and/or sliding

faces

Repair or replace the sleeve

Sleeve movement failure

NG

NG

OK

Shift block sleeve movement

7B1-108 MANUAL TRANSMISSION

Checkpoint

Trouble

Cause

Countermeasure

Synchronizer assembly

Shift arm and synchronizer

sleeve

Replace the worn parts

Replace the worn parts

Worn synchronizer parts

Worn shift arm and/or

synchronizer sleeve groove

Mainshaft and countershaft

thrust play

Replace the worn parts

Worn thrust washer, collar,

and/or gear thrust faces

OK

NG

NG

NG

OK

OK

Continued from the previous

MANUAL TRANSMISSION 7B1-109

3. WALKING OR JUMPING OUT OF GEAR

Checkpoint

Trouble

Cause

Countermeasure

Shift rod and quadrant box

sliding faces

Detent ball

Replace the shift rod and/or

the quadrant box

Replace the detent ball

Worn shift rod and/or sliding

faces

Worn detent ball

Detent spring

Repair or replace the detent

spring

Replace the worn parts

Detent spring weak or broken

Insufficient stroke caused by

sliding position wear and

excessive play

OK

OK

NG

NG

NG

NG

OK

OK

Change lever play

Continued on the next page

Mainshaft and countershaft

thrust play

Replace the worn parts

Worn thrust washer, collar,

and/or gear thrust faces

Replace the worn parts

Worn shift arm and/or

synchronizer sleeve groove

NG

NG

OK

Shift arm and synchronizer

sleeve