Differential Assembly: Testing and Inspection

Noise Diagnosis

Locking Differential Diagnosis
1. Place the vehicle on a frame-contact hoist, allowing free rotation of the rear wheels.
2. Hold one wheel stationary. Slowly rotate the other wheel approximately 1/2 revolution per second in both the forward and reversed directions. The wheel should rotate freely. The differential is locking and is broken if both wheels attempt to turn together.
3. Raise the hoist to maximum height with one person in the vehicle.
4. Start the engine. Ensure that the engine is operating at low idle speed (warm engine).
5. Apply the service brake. Place the automatic transmission in drive. Depress the clutch and place the transmission in first gear with a manual transmission.
6. Lock one rear wheel by pulling one parking brake cable from under the vehicle with the aid of an assistant.
7. Release the service brakes or disengage the clutch slowly enough in order to start the free wheel turning. The locked rear wheel remains stationary.
8. Increase the speed of the free wheel. The differential will lock, causing the rotating wheel to stop or both wheels to turn at the same speed. The engine, if equipped with manual transmission, may stall. In order to cause the differential to lock, you may need to accelerate the engine until approximately 16 km/h (10 mph) is indicated on the vehicle speedometer. If the indicated speed can be increased beyond 32 km/h (20 mph) without causing the differential to lock, the unit is not functioning properly. Rapid release of the brakes or clutch, or rapid acceleration of the engine, will invalidate the test.
9. Lock the opposite rear wheel and repeat the procedure.








Locking Rear Axle Does Not Lock








Locking Rear Axle Locks in Turns





Locking Rear Drive Axle Chatters in Turns

Repair Instructions
Locking Differential Disassemble (8 1/2 and 9 1/2 Case)

^ Tools Required
- J 26252 Posi-Traction Governor Remover





1. Remove the governor bushing using the J 26252.





3. Remove the E-clips that hold the latching bracket on the shaft. Move the bracket down the shaft.
4. Remove the latching bracket bushing using the J 26252.
5. Remove the latching bracket, the shaft, and the spring from the case.
6. Remove the governor assembly from the case.
7. Remove the lock screw.
8. Remove the pinion shaft.
9. Remove the differential pinion gear and pinion thrust washer. Rotate one of the side gears and roll the gears out of the case.
10. Remove the thrust block and the right side gear.
11. Remove the right clutch plates and the side thrust washer.
12. Remove the left side gear, the cam plate, and the clutch plates as an assembly (cam unit).
13. Remove the side gear thrust washer.