1997 ISUZU TFS SERIES check oil

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

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)

7C-40 CLUTCH
HYDRAULEC DAMPER CYLINDER (Except 6VD1 Engine)
INSPECTION AND REPAIR
Make the necessary adjustments, repairs, and part replacements if excessive wear or damage is discovered during
inspection.
Visually check for oil leakage and other damage.
If oil leakage or other damage is discovered during the
inspection; the damper cylinder assembly must be replaced as
a unit.

CLUTCH 7C-41
TROUBLESHOOTING
Refer to this Section to quickly diagnose and repair clutch problems.
Each troubleshooting chart has three headings arranged from left to right.
(1) checkpoint (2) Trouble Cause (3) Countermeasure
This Section is divided into five sub-sections:
1. Clutch Slippage
2. Clutch Does Not Release Properly
3. Clutch Shudder
4. Clutch Noise
1) Clutch pedal Depressed (Clutch Disengaged)
2) Clutch pedal Not Depressed (Clutch Engaged)
5. Oil Leakage

7C-42 CLUTCH
1. CLUTCH SLIPPAGE
Checkpoint Trouble Cause Countermeasure
Adjust the push rod playNo push rod play in the master
cylinder NG
Clean the related parts and/or
replace the facing
Replace the transmission front
cover oil seal
Clean the related parts and/or
replace the facing
Repair or replace the
transmission front cover
Adjust the push rod play
Defective transmission front
cover oil seal
Continued on the next page
Grease or oil adhering to the
facingToo much grease
Transmission front cover
unevenly worn
No push rod play in the slave
cylinder
Clean and grease the shift
blockShift blockInsufficient grease on the front
cover contact surfaces
NG NG NG NG NG
OK
OK
Clutch pedal free play
OK

CLUTCH 7C-43
Checkpoint Trouble Cause Countermeasure
Replace the release bearingRelease bearing broken
Clean the related parts and/or
replace the facing
Replace the crankshaft rear oil
seal
Defective crankshaft rear oil
seal
NG NG
OK OKGrease or oil adhering to the
facing
Clutch diaphragm springReplace the clutch pressure
plate assemblyW eak or broken clutch
diaphragm spring
Replace the driven plate
assemblyWorn facing
NG NG
OKFacing Continued from the previous page