Wheel Bearings Diagnosis (Tapered): Galling

The metal smears on the roller ends are due to overheating, lubricant failure, or lubricant overload. See Fig 1 .

1. Check the seals.
2. Check for proper lubrication.
3. Clean all of the parts and the housings.
4. Replace the bearing. Refer to WHEEL HUB, BEARINGS & SEAL.

Fig 1: Identifying Galling

Courtesy of GENERAL MOTORS CORP.