Subject: | 8.625" Axle Phasing, Growl, Cyclic, Noise While Driving |
Models: | 2005 Cadillac Escalade |
2005 Chevrolet Avalanche, Express |
2005 Chevrolet Silverado, Suburban, Tahoe |
2005 GMC Savana, Sierra, Sierra Denali |
2005 GMC Yukon, Yukon Denali, Yukon XL |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Concern is a phasing, growling, cyclic noise that may sound like it is in the front axle or wheel bearing area. This noise may be difficult to diagnose since it may actually be coming from the rear axle.
Check for possible rear axle noise by using chassis ears or a stethoscope on a suspension contact hoist.
Note: Do not operate AWD vehicles with all 4 wheels off the ground. These vehicles must be driven using the chassis ears to detect noises.
If the listening device detects a noise in the rear axle bearing area, inspect the rear axle shafts for any mis-machining on the bearing surface. Look and feel for any high spots, flat spots, or roughness on the shaft surface where the bearing rides on the shaft.
Replace the shaft and associated bearing.
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.