I don't understand why they hit the hubs, at least why they hit them there? I've done tons of wheel bearings on 911s, I'm not sure how you could get a hammer there, or why you would think it's a good idea... As Jase said there's a tool for it, but even if you didn't have the Porsche tool, or a puller, it doesn't take a genius to get some random bearing press tools and maybe a torch and do it safely. Even then, I'm not sure on a 964 that's a problem... unless you end up scoring or pulling the bearing races apart.
Still, it happens. When I had my shop, my first customer was someone I knew from the Pelican Parts BBS, I didn't even want to have to call him and tell him I was charging him for almost literally everything the previous shop had done on his car a month earlier. Thankfully he only needed 1 new, new hub though.
Note if you ever use a torch to heat the aluminum around the bearing so it'll come out easier... don't catch it as it pops out, regardless of your shops "nothing hits the floor policy" Not that I'm speaking from experience or anything
Quote:
Originally Posted by Vicegrip
Making the determination that this was a direct result of a procedure failure would require more than looking and thinking. Did you contact the tin kickers?
I did some digging after looking at the parts and found that this is not an unheard of failure on a highly stressed point. Your hub failed in the same manner that other hubs that were not beaten on have failed.
2. You have 20,000 high stress miles with some to most using oversized track compound tires and rims that Porsche has in print recommend not be used.
I don't know what happened to your hub at all but here are people that can inspect, test and determine the failure mechanism.
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I'm going to have to disagree here... The reason being you have not only a 964, but an RS America. Also, to put one thing to rest, a 275 is an "approved" tire size with Porsche, you can even run them on Porsche rims. The blue rims in my avatar are pretty rare factory RS wheels that allow running 235/275 on a narrow body car and Porsche raced on them all the time. I don't think your choice of tire size had anything to do with this failure, people run them on 915 and G50 cars all the time, in many wheel combinations... if you were running a 3-piece fuchs I'd call you a fuching idiot, but.... Also, your wheel studs look fine, no bending no shearing... if you were using a really messed up offset wheel, I'd see those failing and the wheel seperating I don't see how those forces would get transferred to the hub and cause it to shear instead.
Here's the other thing, if you look at hub, bearing, and axle failures on 911s, it's kind of like coming to a cliff with 964s. Those are beefy bearings, axles, and hubs. They didn't suffer nearly the same problems as SCs or Carreras. What you're describing is a nearly unheard of problem on RS Americas. Front and Rear wheel bearings were stouter than on older cars, the axle bolts are even bigger and don't back themselves out nearly as much. The fact that the hub is what sheared is honestly shocking. My gut tells me the bearing was possibly improperly installed, but I'd be looking hard at that bearing... I'm not sure what else could cause that without tearing up the axle, transmission, or cv joints first. Especially since you mentioned the heat...
Or the axle nut... did the shop that did this know the torque specs on it? It's a PITA, I've had the "sniper rifle" torque wrench on it, and a jack handle, and have had to stand on the end to get to the required torque settings before.