IMPROVED FRONT AXLE OUTPUT SHAFT RETENTION-PART P/N'S

VEHICLES AFFECTED: 1983-85 'T' Trucks ------------------

During the 1985 model year, a design change to the front driving axle assembly on 1985 'T' Trucks was made for improved axle output shaft retention. The modification in the shape of the differential side gear is shown in Figure No. 1.

Disengagement of the axle shaft may cause internal damage to the differential and axle shaft, but will not cause the shaft to separate from the vehicle. In the event of a disengaged front axle shaft on a 1983-85 'T' Truck, follow the service procedure specified below.

SERVICE PROCEDURE

1. Remove and disassemble the tube and axle shaft assembly, differential carrier and differential case following the procedure outlined in Section 4C of the 1984 or 1985 'S' Truck Service Manual.

2. Replace both output shaft retaining rings, Part Number 14041989.

3. Replace the differential side gears with new part number 15521971.

4. Replace the differential connector gear with new part number 15521970.

5. Inspect for any additional worn or damaged parts and replace as necessary.

6. Reassemble the differential case, carrier assembly, and axle shaft and tube assembly following the procedure in the 1984 or 1985 'S' Truck Service manual.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.