Broken rear hub

[Mike Metzler]

At the track recently I hear a noise that sounded like a rear wheel bearing going bad on my '87. On the drive home, it sounded like BOTH rear wheel bearings were bad (i.e., growled on both left and right turns, quiet when straight). I took it to the shop and they agreed with my prelim. diagnosis. When he started to take things apart, the rear brake rotor nearly fell on his foot -- one rear hub was broken!

He said he had never seen that before, and he has been working on 911s for many years. In fact, he had difficulty getting the part since apparently no-one needs replacement rear hubs.

So, my question is, has anyone else experienced this, and, secondly, any guesses as to why it may have happened?

For what it is worth, the car has just over 62,000 miles on it, and the last half of its life has been ~90% track, 10% street. I have 23/33 torsion bars, TRG sways set ~mid stiffness, and usually run 235/45 and 255/40x17 RA-1. Rear camber is ~-2.5 deg. Anything else that might be relevant?

Thanks much!
Mike

(gatuitous pic from the day it broke...)

[davidppp]

Hello, Mike.

The starting point is a macro then mictro examination of the part.

Do you have good pix if the bits?

Kind regards
David

[Mike Metzler]

Unfortunately, I will not be able to get to the car for a week or so. At that time I will get some pictures and post.

Thanks!

Mike