Initial Inspection and Diagnostic Overview

Inspection and Verification
Certain axle and driveline symptoms are also common to the engine, transmission, wheel bearings, tires, and other parts of the vehicle. For this reason, be sure that the cause of the concern is in the axle before disassembling, adjusting or repairing the axle.

Certain driveshaft vibration symptoms are common to the Front Engine Accessory Drive (FEAD), the engine, transmission or tires. Be sure the cause of the concern is the driveshaft before repairing or installing a new driveshaft.


Noise Acceptability
A gear-driven unit will produce a certain amount of noise. Some noise is acceptable and audible at certain speeds or under various driving conditions, such as a newly paved blacktop road. Slight noise is not detrimental to the operation of the axle and is considered normal.


Flex Coupling Inspection
Check for visible signs of tearing, cracking or wear in the reinforcing cord. If the flex couplings show signs of damage, inspect the axle and subframe mounts for cracking or tearing.


Driveshaft Center Bearing Universal Joint (U-Joint) Inspection
Place the vehicle on a frame hoist and rotate the driveshaft by hand. Check for rough operation or a seized U-joint. The U-joint is not repairable, a new driveshaft must be installed if the U-joint shows signs of seizure, excessive wear, or incorrect seating.


Driveshaft Center Bearing
Rotate the driveshaft by hand. If the bearing shows signs of roughness or is noisy, install a new bearing assembly.