Whine Noise From Front Axle (Diagnose and Replace Front Propeller Shaft with a Tuned Internally Dampened Front Propeller Shaft)

Some customers may comment on a slight whine noise from the front of the vehicle during light throttle conditions, typically at two vehicle speed ranges of 64-80 km/h (40-50 mph) and 112-129 km/h (70-80 mph).

"Inherent" ring and pinion gear whine.

All gear driven units, such as automotive rear axles, produce some level of noise that cannot be eliminated with conventional adjustments and repairs. "Inherent" axle noise can be described as a slight noise heard only at a certain speed on most General Motors® trucks. The presence of this noise is not indicative of a functional concern with the axle assembly. However, some customers may find that this "inherent" axle noise is unacceptable.

Replace the front propeller shaft with an internally tuned dampened shaft ONLY after diagnosis concludes that it is an "inherent" front axle noise and no physical damage or incorrect adjustment exists.

Diagnostic Information and Procedure for Front Axle Noise

Front Propeller Shaft Replacement

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle (SI Document ID #737171).

Important: Before disassembly, observe and accurately mark all of the driveline components relative to the propeller shaft and to the axles. These items include the following components:

•	The propeller shafts

•	The wheel drive shafts

•	The pinion flanges

•	The output shafts

Assemble all of the components in the exact relationship to each other prior to removal. Observe all published specifications and torque values and any measurements obtained prior to disassembly.
2. Remove the transfer case shield, if equipped.



3. Remove the clamp (if applicable) (4) at the transfer case (3) by prying up the exposed end of the clamp (4) with a flat-bladed tool.



4. Remove the bolts (6) and the yoke retainers (7) from the front axle pinion yoke (1).

Notice: When removing the propeller shaft, do not attempt to remove the shaft by pounding on the yoke ears or using a tool between the yoke and the universal joint. If the propeller shaft is removed by using such means, the injection joints may fracture and lead to premature failure of the joint.

5. Disconnect the propeller shaft (2) from the front axle pinion yoke (1).
6. Remove the propeller shaft (5) from the transfer case output shaft by sliding the propeller shaft forward.
7. Inspect the splines of the transfer case output shaft for a sufficient coating of lubricant. If the output shaft does not have a sufficient coating of lubricant, lubricate the shaft with lubricant, P/N 12345879 (Canadian P/N 10953511), or with an equivalent lubricant meeting GM specification 9985830.

Important: Some old driveshaft boots may only use a single clamp design. When installing the new propeller shaft, use ONLY a two clamp boot.

8. Install the new clamp, P/N 26064275, supplied with the new propeller shaft, P/N 15186002, into the groove of the propeller shaft boot.
9. Install the propeller shaft splines into the transfer case output shaft.
10. Install the propeller shaft to the front axle pinion yoke.
11. Install the yoke retainers and the bolts.

Tighten
Tighten the yoke retainer bolts to 25 N·m (19 lb ft).

12. Install the boot onto the transfer case output shaft until the boot is attached into the groove on the output shaft.



13. Using the J 43218 , crimp the clamp until the dimensions that are shown are obtained.
14. Install the transfer case shield, if equipped.
15. Install the transfer case shield mounting bolts, if equipped.

Tighten
Tighten the transfer case shield mounting bolts to 20 N·m (15 lb ft).

16. Lower the vehicle.

Parts are in limited quantities. DO NOT order parts for stock.

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use: