Gear Howl and Whine

NOTE: Before disassembling the axle to diagnose and correct gear noise, eliminate the tires, exhaust, trim items, roof racks, axle shafts and wheel bearings as possible causes.

The noises described under Road Test usually have specific causes that can be diagnosed by observation as the unit is disassembled. The initial clues are the type of noise heard on the road test and the driving conditions.

Bearing malfunctions will normally be obvious at disassembly. As noted earlier, differential pinion bearings make a high-pitched, whistling noise, usually at all speeds. However, if there is only one differential pinion bearing that is malfunctioning, the noise may vary in different driving phases.

Differential pinion bearings should not be replaced unless they are scored or damaged or there is a specific differential pinion bearing noise. Examine the large end of the rollers for wear. If the differential pinion bearings original blend radius has worn to a sharp edge, the differential pinion bearing should be replaced.

NOTE: The low-pitched rumble of a malfunctioning wheel bearing can also be caused by the exterior luggage rack or tires.





Wheel bearing noise might be mistaken for pinion bearing noise. Check the wheel bearing for a (A) spelled cup, a (B) spelled roller and/or damaged rollers. Replace the wheel bearing if any of these concerns are detected.





If the wheel bearing is damaged, the roller surface on the axle shaft may also be damaged. Replace the axle shaft if any damage is detected.