oil ISUZU TFS SERIES 1997 Repair Manual

4C1-80 FRONT WHEEL DRIVE
TROUBLESHOOTING
Refer to this Section to quickly diagnose and repair front axle problems. Each troubleshooting chart has three
headings arranged from left to right.
(1) Checkpoint (2) Trouble Cause (3) Countermeasure
This Section is divided into ten sub-sections:
42 Model
1. Wanders and pulls
2. Front wheel shimmy
44 Model
1. Oil leak at front axle
2. Oil leak at pinion shaft
3. Noises in front axle drive shaft joint
4. Noises in front axle
5. Wanders and pulls
6. Front wheel shimmy
7. Automatic locking free wheel hub
1) Does not lock or locks only on one side
2) Does not freewheel or freewheels only to one side
3) Noises in automatic locking free wheel hub
Propeller shaft
1. Noise
2. Vibration

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

4C1-92 FRONT WHEEL DRIVE
ITEM NO. ILLUSTRATION PART NO. PART NAME
FAL-42
5-8840-0126-0
(J-8001)Dial indicator
(for 167mm,194mm)
FAL-37
5-8840-2086-0
(J-23597-4)Disc (2 pcs. required)
(for 167mm)
FAL-43
5-8840-0128-0
(J-23597-1)Arbor
(for 167mm, 197mm)
FAL-38
5-8840-2088-0
(J-23597-8)Disc (2 pcs. required)
(for 194mm)
FAL-59
9-8522-1165-0
(J-6133-01)Pinion bearing installer
(for 4WD)
FAL-52
9-8522-1275-0
(J-24250)Pinion oil seal installer
(for 194mm)
FAL-53
5-8522-0046-0
(J-26234)Pinion oil seal installer
(for 167mm)
FAL-55
5-8840-0138-0
(J-29036)Side bearing installer
(for 167mm)
FAL-56
9-8521-1164-0
(J-24244)Side bearing installer
(for 194mm)

FRONT WHEEL DRIVE 4C1-93
ITEM NO. ILLUSTRATION PART NO. PART NAME
FAL-57
5-8522-0053-0
(J-29016)Outer bearing installer
(for 2WD)
FAL-58
5-8522-0054-0
(J-29015)Inner bearing installer
(for 2WD)
FAL-54
5-8522-0051-0
(J-33161)Hub oil seal installer
(for 2WD)
FAL-62
5-8840-2117-0
(J-36827) Hub nut wrench
FAL-17
5-8840-2119-0
(J-36829)Outer bearing inner race
installer (for 4WD)
FAL-19
5-8840-2120-0
(J-36830) Oil seal installer (for 4WD)
FAL-18
5-8840-0054-0
(J-29015)Outer bearing outer race
installer (for 4WD)
FAL-61
5-8840-2137-0
(J-38194) Inner cam installer
FAL-395-8840-2126-0Auto locking shim gauge
(for 4WD)

5-22 BRAKES
1. Fill the brake fluid reservoir with brake fluid.
Handle the brake with reasonable care to avoid spillage as it
is damaging to paint.
Note:
Take care to prevent foreign matter from entry, when
replenishing or replacing brake fluid.
When pouring brake fluid, if diaphragm in the oil tank cap
is stretched, be sure to place it into original position,
(fasten it), and then cap it.
2. Connect a vinyl pipe to the bleeder screw on the wheel
cylinder, caliper bode or LSPV and the other end of the pipe
in a transparent container.
3. Pump the brake pedal several times and hold it depressed.
Loosen the bleed screw to release brake fluid together with
air bubbles.
Tighten the bleeder screw before pressure is released
completely.
4. Repeat the step in paragraph 3 above until the air bubbles
disappear completely.
Securely tighten the bleeder screw when the air bubbles
disappear completely.
5. Repeat the step in paragraph 4 above on the remaining
wheel cylinders.
Bleed the system starting with rear side farthest from the
brake fluid reservoir.
6. Fill the brake fluid reservoir to the specified level.
Pour brake fluid carefully so as not to produce air bubbles.
7. If the cap diaphragm is stretched, fasten the diaphragm and
the sure to cap it after it is placed to the original position.
Note:
Never reuse the old brake fluid.

5-48 BRAKES
Important Operations
When disassembling, inspecting or reassembling the master
cylinder assembly, take care not to bring the parts into contact
with mineral oil or dust. Wash the piston cups only with brake
fluid. Do not use gasoline or other mineral-base cleaning
solvents.
5. Ring ; Snap
Remove the snap ring from the cylinder body with pushing in
the primary and secondary pistons.
6. Bolt ; Stopper
Push in the primary and secondary pistons and remove the
stopper bolt completery from the cylinder body, then remove
the primary and secondary piston assemblies.
8. Piston Assembly ; Primary and Spring
9. Piston Assembly ; Secondary and Spring
Don’t remove the spring from the piston.

BRAKES 5-67
TROUBLESHOOTING
Condition and Cause Correction
Poor Brake Action
Master cylinder faulty Correct or replace
Power cylinder faulty Correct or replace
Level of brake fluid in reservoir too low Replenish and bleed
Air in hydraulic circuit Bleed
Front disc brake caliper faulty Clean or replace
Rear brake wheel cylinder faulty Clean or replace
Water or oil on brake pads or linings Clean or replace
Brake pads or linings hardened Replace
Brake pads or linings in poor contact with rotor or brake drum Correct
Brake pads or linings worn Replace
Brake disc or drum rusted Grind or replace
Check valve in vacuum hose faulty Correct or replace
Brake Squeak
Brake pads or linings worn Replace
Brake pads or linings hardened Replace
Brake pads or linings in poor contact with rotor or brake drum Correct
Brake disc(s) warped, worn or damaged Grind or replace
Disc brake anti-squeak shims fatigued Replace
Front hub bearings loose or preload is incorrect Adjust or replace
Brake disc or drum rusted Grind or replace
Brake Pull
Tire inflation pressures unequal Adjust
Front wheel alignment incorrect Adjust
Water or oil on brake pads or linings Clean or replace
Brake pads or linings hardened Replace
Brake pads or linings worn excessively Replace
Brake drum or rotor worn or scored Grind or replace
Front or rear wheel cylinder or disc brake caliper malfunctioning Clean or replace
Front hub bearing preload incorrect Adjust or replace
Brake pad or lining clearances unequal Adjust or replace
Brake Drag
Parking brake maladjusted Adjust
Brake pad or lining clearance insufficient Adjust
Brake pedal free play insufficient Adjust brake pedal height or power cylinder operating rod
Piston in master cylinder sticking Clean or replace
Pistons in disc brake caliper sticking Replace piston seals
Pistons in rear brake wheel cylinders sticking Clean or replace
Brake pads sticking in caliper Clean
Return springs weakened Replace
Parking brake binding Overhaul rear brakes
Front hub bearing preload incorrect Adjust or replace
Rear brake shoes not returning Correct or replace brake back plate, check automatic adjuster and
replace as necessary
Obstructions in hydraulic circuit Clean
Rotor warped excessively Grind or replace
Rear brake drum distorted Grind or replace
Piston cups swollen Replace brake fluid and piston cups
Check valve ; vacuum hose faulty Replace
Parking cable sticking Clean or replace
Rear disc brake over adjust Adjust or overhaul rear brakes
Excessive Brake Pedal Travel
Air in hydraulic circuit Bleed hydraulic circuit
Level of brake fluid in reservoir too low Replenish brake fluid reservoir to specified level and bleed hydraulic
circuit as necessary.
Master cylinder push rod clearance excessive Adjust
Leakage in hydraulic system Correct or replace defective parts
Rear disc brake autoadjuster malfunction Overhaul rear brakes

7C-24 CLUTCH
Wedge Collar (6VD1)
1. Visually check the surfaces of the wedge collar making
contact with the release bearing for excessive wear and
damage.
2. Replace any exhibiting excessive wear damage.
Shift Fork (Except 6VD1)
1. Visually inspect the surfaces of the shift fork making contact
with the shift block for excessive wear and damage.
2. Remove any minor stepping or abrasion from the shift block
with an oil stone.
Replace any exhibiting excessive wear or damage.
3. Apply multi-purpose type grease (NLGI No.2 or No.3) to
area.
6VD1Shift Fork (6VD1)
1. Visually check the surfaces of the shift fork making contact
with the release bearing for excessive wear and damage.
2. Remove any minor stepping or abrasion from shift fork with
an oil stone.
Replace any exhibiting excessive wear of damage.
DRIVEN PLATE ASSEMBLY
1. Visually inspect the torsion spring
1 for looseness,
breakage, and weakening.
If any of these conditions are discovered, the driven plate
assembly must be replaced.
2. Visually inspect the facing surfaces
2 for cracking and
excessive scorching.
Visually inspect the facing surfaces for the presence of oil or
grease.
If any of these conditions are discovered, the facing must be
cleaned or replaced.

CLUTCH 7C-25
3. Check that the driven plate moves smoothly on the
transmission top gear shaft spline.
Minor ridges on the top gear shaft spline may be removed
with an oil stone.
Driven Plate Warpage
1. Insert the clutch pilot aligner into the driven plate splined
hub.
The clutch pilot aligner must be held perfectly horizontal.
Clutch Pilot Aligner : 5-8840-2634-0 (HEC Engine Series)
5-8525-3001-0 (J-24547) (Except HEC Engine Series)
2. Set a dial indicator to the driven plate outside
circumference.
3. Slowly turn the driven plate.
Read the dial indicator as you turn the driven plate.
If the measured value exceeds the specified limit, the driven
plate assembly and/or the facing must be replaced.
Driven Plate Warpage mm(in)
Standard Limit
0.7 (0.028) 1.0 (0.039)
Driven Plate Splined Hub Spline Wear
1. Clean the driven plate splined hub.
2. Install the driven plate to the transmission top gear shaft
spline.
3. Set a surface gauge to the driven plate outside
circumference.
4. Slowly turn the driven plate counterclockwise.
Measure the spline rotation play as you turn the driven
plate.
If the measured value exceeds the specified limit, the driven
plate assembly must be replaced.
Driven Plate Splined Hub Spline Wear mm(in)
Standard Limit
0.5 (0.020) 1.0 (0.039)