Front Axle Grind Whine Noise in 2WD, Gone in 4WD - keywords 231 233E 236 axle bearing case differential front gear HI2 HI4 loud moan pinion rough transfer vibration
| Subject: | Front Axle Grind Whine Noise in 2WD Gone in 4WD |
| Models: | 1997-2004 Chevrolet S-10 |
| 1997-2005 Chevrolet Blazer |
| 1997-2004 GMC Sonoma |
| 1997-2005 GMC Jimmy |
| Equipped with 4WD |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
97-04 T1 vehicles with a grinding noise/vibration from the front axle in 2WD only. The noise is not present in 4WD. Front axle side/pinion gear finish, thrust washer worn, pilot bearing in stub shaft worn, and/or front suspension trim height incorrect.
Recommendation/Instructions:
Install the Chassis Ears on the front axle assembly or a rubber hose on the front axle vent tube long enough to reach the cab of the vehicle. Use the hose to verify that the noise is coming from the front axle assembly.
If the noise can be isolated to the front axle:
- Inspect the front axle housing for possible ground out to chassis, i.e. mount brackets, housing casting, etc.
- If no ground out is detected then confirm that the suspension "Z" height is correctly adjusted.
If no trouble is found with the procedure outlined above, remove the differential assembly and replace the following front axle components:
Part name | Illustration # as found in SI Document # 856787 |
|---|---|
Carrier/case assembly | 37 |
Side/spider gear kit | 57,58,59,60,61,62,63,64 |
Pilot bearing | 11 |
Thrust washer kit includes | 8,10,and 24 |
** Right axle bearing | 4 |
** Inspect and replace only if necessary
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
