So I pulled the front rotors today and while I was inspecting the passenger side spindle, I noticed what I believe to be discoloration from overheating of the inboard bearing.  I looked at the bearing and it's not damaged, but the grease is mostly carbon now.  The outer race of the bearing shows some heat damage, but nothing too bad.  My question is (gulp)    should I replace the spindle/steering knuckle, or can I continue to use it for a while with the intent to replace it in a year or so...

Carl;

I feel your pain.  I took my '80 in to get it tuned by our local Vette expert and he mentioned that my rear spring and the half shaft U-joints need replacing BEFORE the wife and I go to Eureka Springs in October.

Seems like it never ends on these 30 year old used cars.  Oh well, I think the folks at our local spring shop can retemper the old one and U-joints aren't that expensive.

I'll be interested to see what Joel (Adams' Apple) and others have to say about your spindle.  If the spindle itself isn't blued from heat after you clean it off with brake cleaner, I would replace the inner and outer bearings and races for safety's sake and move on but I'm certainly no expert. 

A catastrophic failure from a spindle cracking is an ugly sight any way you slice it.

Good Luck!
dnv2007-07-22 19:52:32

You said a mouth full Dennis. If that metal is tempered to the point of being brittle from heat, it should take a decent impact (pothole) to break it. Life is full of gambles, but only you know how you drive it , and how much. A year's not long to put it off for all the miles we get on our vettes at my house. Good luck. It sure is nicer when you can plan these repairs, eh ?

Depends on your definition of discoloration...some spindles will have a slightly dark color to them on the un-machined surface between the bearings. If the machined area where the bearing actually sits is blue, that would concern me. If that area is nice and "shiny", with maybe some brownish coloring to it, I wouldn't be worried.
You say the outer race shows some heat damage. Is it blue, or just a black color? Blue would be heat, black would be wear.
Could you post a pic or two, to give us a better view of what you are seeing?