Ford Transit 2002 Owner's Manual page 1219

6. NOTE: Overheating can cause loss of surface
hardness.
Check for a dark blue colour caused by
overheating (yellow or brown is normal) due to
excessive pre-load or inadequate lubrication.
Install a new bearing, new seals and check
other components as necessary.
7. Check the surfaces for abrasion due to metal
fatigue.
Install a new bearing and clean all other
affected components as necessary.
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