TCM FD35C9 - 4.4 Reduction Gear and Differential Troubleshooting; 4.5 Brake System Troubleshooting

4-3
4.4 REDUCTION GEAR AND DIFFERENTIAL
Problem Possible cause Remedy
1. Noisy differential
Problems with the differential will usually appear as a noise. However, you may confuse noise from the
differential with that from the engine, mufer, torque converter transmission, reduction gear, wheels, or wheel
bearings. When checking the differential, make sure that noise comes from the differential, not from other
components.
(1) Noisy gear in driving
Gear oil level is low or improper quality
Add oil or change gear oil
(SAE90) API GL-4 or higher.
Ring gear teeth worn or damaged Repair or replace.
Bearing worn or damaged Replace bearing.
Drive shaft splines worn Replace shaft.
(2) Noisy gear during
traveling
Pinion gear or side gear teeth worn or damaged Repair or replace.
Pinion gear or side gear thrust plate worn Replace thrust plate.
Spider worn Replace spider.
(3) Noise produced when
the truck makes turns
Pinion gear or side gear worn or damaged Replace worn part.
Spider worn Replace spider.
Pinion gear or side gear thrust plate worn Replace thrust plate.
2. Malfunction of differential
If the differential fails to operate normally, jack up the front wheels and check the differential from the front
tire side to verify that the cause of the trouble lies in the differential.
(1) The truck won’t start
when accelerator pedal
is pressed
Drive shaft splines worn Replace drive shaft.
Drive shaft damaged Replace drive shaft.
Ring gear teeth damaged Replace ring gear.
(2) The truck cannot travel
or causes loud noise
Foreign matter caught in the mechanism Clean or replace.
Ball bearing damaged Replace bearing.
Drive shaft damaged Replace drive shaft.
Ring gear teeth damaged Replace ring gear.
4.5 BRAKE
Problem Probable cause Remedy
1.
Front wheel hub noisy
Improper tightening of wheel bearing Retighten.
Wheel bearing damaged Replace bearing.
2.
Poor braking effect
Too large clearance between drum and lining Adjust clearance.
Air mixed in brake oil Bleed air.
Low brake oil level Add brake oil.
Lining contaminated with oil
Disassemble and repair oil
leaks and replace lining.
Brake oil leakage
Check piping and cylinder
and repair.
Brake booster defective Repair or replace.
3.
Brake drags
Brake shoe maladjusted Adjust properly.
Wheel cylinder and piston seized from
corrosion
Replace.
Loosen wheel bearing Retighten lock nut.
Brake shoe return spring damaged Replace spring.