The brown was from either corrosion or overheat. It is not normal. My guess is that it was from overheating. Overheating first shows up as a "straw" color on the metal surface before going to purple, blue, then black. Corrosion would have shown up with brown grease in the assembly.

The outboard race set sees more "torture" than does the inboard race. This is from cornering forces. So what you saw made sense.

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95 E320 Cabriolet, 169K