Front Axle Drive Shaft Seal - Wears Out Early
File In Section: 3 - Steering/SuspensionBulletin No.: 56-33-01A
Date: December, 1995
Subject:
Early Front Axle Front Wheel Drive Shaft Seal Wear-out (Replace Lower Control Arm or Install Seal Cover)
Models:
1988-95 Chevrolet and GMC Truck K Models - Plant Codes Z, 1, E
Built Prior to VIN Breakpoints:
1995 Chevrolet and GMC Truck K Models - Plant Code J
Built Prior to VIN Breakpoints:
This bulletin is being revised to correct the "Models" involved information. Please discard Corporate Bulletin Number 56-33-01 (Section 3 - Steering/Suspension).
Condition
Some owners of vehicles which operate primarily in off-highway environments may comment on premature wear-out of the front axle seals (front wheel drive shaft CV boots).
Cause
Off-highway usage can result in the build-up of debris (mud, ice, etc.) on the lower control arm. If the amount of debris is excessive, contact with the front axle front wheel drive shaft seal may result. The result may be an early wear-out of the seal.
Correction
Important:
Implementation of this bulletin by Canadian dealers on vehicles within warranty period requires prior DSM approval.
K - Models with 8600 # GVW's and Below
For K trucks with 8600 # GVW's and below, a new lower control arm is available featuring an opening under the front axle outboard boot (Figure 1). The opening should prevent the build-up of debris by allowing the debris to fall through.
The new lower control arm went into production after the beginning of the 1995 model year starting with the VIN breakpoints listed above.
Additionally, for vehicles operating in severe usage environments (snow plows, mines, etc.) a front axle seal cover is available and can be used in conjunction with the new lower control arm (Figure 2). The purpose of this protective device is to sweep as much debris as possible from the lower control arm. This should extend the life of the front axle seal.
It should be noted however that the protective seal cover WILL, during its useful life, take on a ragged appearance while still adequately protecting the drive axle seal. The device is functioning as long as the fabric continues to sweep debris from the lower control arm.
K - Models with GVW's Above 8600 #
For K-models with GVW's above 8600 # a front axle seal cover is available (Figure 2). The purpose of this protective device is to sweep as much debris as possible from the lower control arm. This should extend the life of the front axle seal.
It should be noted however that the protective seal cover WILL during its useful life, take on a ragged appearance while still adequately protecting the drive axle seal. The device is functioning as long as the fabric continues to sweep debris from the lower control arm.
Lower Control Arm Replacement Procedure (K-Trucks with 8600 # GVW's and Below)
Following the procedure given in section 3C of the service manual, replace the lower control arms with the new style lower control arms. It should be noted that the new lower control arms include a pressed in ball joint. Part numbers for the lower control arm front and rear bushings are also given below.
Front Axle Seal Cover Installation Procedure
Follow the instructions included in the seal cover service kits. Appropriate part numbers are shown below.
Be sure to order the correct seal cover based on the GVW of the subject vehicle.
Parts Information
Parts are currently available from GMSPO.
Warranty Information
Important:
Implementation of this bulletin by Canadian dealers requires prior DSM approval. Installation of seal cover service kits is an 'owner pay' service and as such requires prior owner approval.
For vehicles repaired under warranty.