FRONT DIFFERENTIAL GROWL REPLACE DIFFERENTIAL GEARS

VEHICLES AFFECTED: 1988-89 K1, K2 TRUCKS

Front axle growl noise due to improperly machined side and differential gears may be evident in some 1988-89 K1 and K2 vehicles. Affected vehicles can be repaired by replacing the front axle side and differential gears only when all of the following criteria are true.

1. Growl noise happens in two wheel drive only. Subject noise will not be evident when the truck is in four wheel drive.

2. The noise is intermittent - the growl will not always be present under the same conditions.

3. Putting pressure (pulling back) on the transfer case shift lever causes the noise to go away.

If all of those conditions are not present, do not attempt this repair procedure as it will not yield the desired result.

REPAIR PROCEDURE:

Replace the front axle side gears as shown in section 4C of the applicable model year unit repair manual.

Refer to Figure 1.

IMPORTANT: The new front differential gear service kit has non-identical side gears. The bell end has a ring, output shaft connector (snap ring) and the flange end has a straight spline with no snap ring.

SERVICE PARTS INFORMATION:

Part Number Description

26022410 Gear Service Kit (2 side gear assemblies, 4 thrust washers, pinion shaft, and pinion shaft lock pin)

Parts are currently available through CANSPO.

WARRANTY INFORMATION:

For vehicles repaired under warranty use:

Labour Operation: F2122

Labour Time: 2.8 hours

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.