Auto Locking Hubs - Not Locking/Unlocking

Models
1981-1984 "W" Model Trucks Equipped With Automatic Locking Hubs


Subject
Automatic Locking Hubs Will Not Operate During Low Temperatures


Index
FRONT SUSPENSION


Date
October 28, 1985

No.
02-10-85



SYMPTOM/CONDITION

Customer concern of automatic locking hubs not locking/unlocking during below freezing weather.

DIAGNOSIS

Road test the vehicle and check for hubs locking/unlocking.

NOTE:
IF AMBIENT TEMPERATURES ARE ABOVE FREEZING, THE HUBS MAY OPERATE PROPERLY, THEN VISUAL INSPECTION IS REQUIRED. REMOVE THE COVER FROM THE HUB. INSPECT THE HUB FOR THE PRESENCE OF WATER CONTAMINATION. THIS WILL APPEAR IN THE FORM OF DISCOLORED GREASE OR RUST.

If the hub is water contaminated, perform the following operation:

PARTS REQUIRED

Hub Repair Package PN 4411998 (as required)

REPAIR PROCEDURE

1. Remove hub from axle.

2. Inspect the hub carefully to determine the extent of the water damage. If the hub components are corroded beyond repair, replace the hub assembly with new hub, PN 4384120.

If damage to the hub is light, do the following:

3. Disassemble the hub and clean thoroughly to remove all contaminants Refer to Rear Wheel Drive Truck Service Manual for service procedure.



4. Inspect all components, especially the drag sleeve, brake band, and inner and outer cages for damage. Replace as necessary.

5. Reassemble the hub.

6. Lubricate the hub by dipping all components except the bearing and race assembly, brake band, and drag sleeve assembly in automatic transmission fluid.

7. Allow the excess transmission fluid to drip off.

8. Repack the bearing and race assembly with Darmex Lubricant, PN 4293040.

9. Lubricate the brake band and drag sleeve with Darmex Lubricant, PN 4293040.

IMPORTANT:
DO NOT SUBSTITUTE ANY OTHER LUBRICANT FOR THE DARMEX LUBRICANT SPECIFIED IN STEPS 8 AND 9, OR FAILURE OF THE HUB TO OPERATE PROPERLY COULD RESULT.

10. Reassemble and install the hub as outlined in the service manual.

11. Install new cover and screws with "O" rings, PN 4411998.

12. Torque the cover screws to 40-50 inch pounds (4.5 - 5.6 N-m).

13. Check the hubs for locking/unlocking.


POLICY:
Information only