REAR AXLE DIFFERENTIAL NOISE (SERVICE PROCEDURE)

SUBJECT: REAR AXLE DIFFERENTIAL NOISE/INOPERATIVE (SERVICE PROCEDURE)

MODELS: 1990-92 C6H/C7H TOPKICK/KODIAK WITH EATON 19050 SINGLE AND 2 SPEED REAR AXLES

Some 1990-92 C6H and C7H Topkick/Kodiak Trucks equipped with Eaton 19050 single or two speed rear axles, may experience a noisy differential which may lead to an inoperative rear axle. This condition is most prevalent in off road applications and is caused when the differential side gears wear and affect other differential components.

NOTE: THE 19050 REAR AXLE IS NOT RECOMMENDED FOR ON/OFF HIGHWAY APPLICA- TIONS.

This condition can be repaired by cleaning the entire rear axle cavity, replacing damaged differential components, checking rear wheel bearing adjustment, installing smaller diameter axle shafts and refilling the axle cavity with synthetic lubricant. Refer to axle shaft replacement and rear wheel bearing adjustment in the medium duty service manual. Also refer to GMC Truck Service Bulletin 93-0B-6 (Corp. No. 260201) for the correct rear axle lubrication procedure.

SERVICE PARTS INFORMATION

Part Number Description Quantity ------ ----------- -------- 12345841 1 Gallon Synthetic Lubricant: Eaton 190505 (RPO H11) 4 Eaton 19050T (RPO H17) 5 12542989 LH. RH Axle Shafts 2

Parts are expected to be available on 12/07/92. In case of limited inventory, parts will be placed on 400 control to waive VIP surcharges. Only verifi- able emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealers expense and all other order types will be placed on back order until the 400 control is removed.

WARRANTY INFORMATION

Labor Labor Operation Description Time --------- ----------- ----- F1540 Right Axle Shaft Replace 0.3 hr.

F1541 Left Axle Shaft Replace 0.3 hr.

NOTE: For Other Labor Operations, applicable to differential repair, refer to the labor time guide.

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.