1997 ISUZU TFS SERIES Workshop Manual

4C1-82 FRONT WHEEL DRIVE
2. FRONT WHEEL SHIMMY
Checkpoint Trouble Cause Countermeasure
Ball joint or bush
Shimmy damper
Replace the ball joint or bush
Replace the shimmy damper
Worn
Worn
Front alignmentAdjust the front alignment
Adjust or replace
Incorrect
W orn or improperly adjusted
OK
OKNG NG NG NG
OK OKW heel bearing
Shock absorber
Steering gear out of
adjustment
Replace the shock absorber
Tighten or replace
Worn
Incorrect or broken
TireReplace or adjust the inflation
Tighten or replace
W orn or improperly inflated
Loose or worn
OK
NG NG NG NO
OK OKSteering linkage

FRONT WHEEL DRIVE 4C1-83
44 MODEL
1. OIL LEAK AT FRONT AXLE
Checkpoint Trouble Cause Countermeasure
Front axle housingRepair or replaceCracked
Replace the oil sealW orn or defective oil seal
NG NG
OKOil seal
2. OIL LEAK AT PINION SHAFT
Oil sealReplace the oil sealW orn or defective
Correct the oil levelToo much gear oil
NG NG
OKGear oil level
Pinion flangeTighten or replaceLoose or damaged NG OK
3. NOISES IN FRONT AXLE DRIVE SHAFT JOINT
Replace the drive shaft joints
and bellowsBroken or worn NGDrive shaft joints and bellows
(B.J and DOJ)

4C1-84 FRONT WHEEL DRIVE
4. NOISES IN FRONT AXLE
Checkpoint Trouble Cause Countermeasure
Replenish the gear oilInsufficient gear oil NG
Replace the wheel bearing
Replace the pinion shaft
bearing
Replace the ring gear pinion
gear or side gear
Replace the gear oil
W heel bearingWorn
Pinion shaft bearingWorn
W orn or chipped
W rong or poor grade gear oil
Ring gear, pinion gear or side
gear
Adjust the backlashDrive pinion to ring gear
backlashToo much or too little backlash
NG NG NG NG NG
OK OK
OK
OK
Oil level
Tighten or replaceDifferential bearingLoose or worn NG OK

FRONT WHEEL DRIVE 4C1-85
5. WANDERS AND PULLS
Checkpoint Trouble Cause Countermeasure
Adjust the wheel bearing
preloadToo tight NG
Tighten or replace
Replace or adjust the inflation
Adjust the steering gear out of
adjustment or replace
Adjust the front alignment
SuspensionFront or rear suspension parts
loose or broken
TabW orn or improperly inflated
Incorrect or broken
Front alignmentIncorrect
Steering gear out of
adjustment
Tighten or replaceSteering linkageLoose or worn
NG NG NG NG NG
OK OK OK
OK
OK
W heel bearing preload

4C1-86 FRONT WHEEL DRIVE
6. FRONT WHEEL SHIMMY
Checkpoint Trouble Cause Countermeasure
Ball joint or bush
Shimmy damper
Replace the ball joint or bush
Replace the shimmy damper
Worn
Worn
Front alignmentAdjust the front alignment
Adjust or replace
Incorrect
W orn or improperly adjusted
OK
OKNG NG NG NG
OK OKW heel bearing
Shock absorber
Steering gear out of
adjustment
Replace the shock absorber
Tighten or replace
Worn
Incorrect or broken
TireReplace or adjust the inflation
Tighten or replace
W orn or improperly inflated
Loose or worn
OK
NG NG NG NO
OK OKSteering linkage

FRONT WHEEL DRIVE 4C1-87
7. AUTOMATIC LOCKING FREE WHEEL HUB
(1) DOES NOT LOCK OR LOCKS ONLY ON ONE SIDE
Note :
1. Stop the vehicle
2. Shift the transfer lever to 4H or 4L
3. Now start driving the vehicle and the
hubs will lock automatically.
4. Once the hubs are locked, they will
remain locked, even if the transfer lever
is shifted from 4L or 4H into 2H, as long
as the vehicle travels in a same
direction.
Checkpoint Trouble Cause Countermeasure
ReplaceStill will not lock NGTry locking procedure once
more
(2) DOES NOT FREEWHEEL OR FREEWHEELS ONLY TO ONE SIDE
Note :
Freewheel operation
1. Stop the vehicle
2. Shift the transfer lever to 2H
3. Back up the vehicle for three or four feet;
this will disengage the front differential.
Checkpoint Trouble Cause Countermeasure
ReplaceStill will not freewheel
Driver the vehicle for five
minutes and then try the
freewheel procedure again
Still will not freewheel NGTry freewheel procedure once
more

4C1-88 FRONT WHEEL DRIVE
(3) NOISES IN AUTOMATIC LOCKING FREE WHEEL HUB
Note :
Some noise at the time of shifting from
“LOCK” to “FREE” or vice versa is normal.
It is not a sign of trouble.
Checkpoint Trouble Cause Countermeasure
Operating of automatic locking
free wheel hubReplace the driven clutchOne side operating
Connect the axial play or
replace the driven clutchExcessive axial play
NG NG
OKHoldout ring axial play
Front axle or jointReplace or tightenDamaged or loose NG OK

FRONT WHEEL DRIVE 4C1-89
PROPELLER SHAFT
1. NOISE
Checkpoint Trouble Cause Countermeasure
Spider bearingReplaceWorn or jammed
ReplaceDamaged or worn
NG NG
OKYoke spline
2. VIBRATION
Shaft balanceAdjustUnbalance
ReplaceIncorrect
NG NG
OKShaft runout
Transmission rear housing
bushing, transfer case
housing bushing
ReplaceWorn NG OK
Yoke splineReplaceJammed NG OK