Actually I think this is a great thread to revisit. Our cars are old enough now that if you guys are regularly tracking them you really should consider replacing the axles / hubs / wheel bearings at a minimum at this point as a preventative measure.

I started going through wheel bearings at an alarming rate last year. After the second set went bad by August we realized that the hubs had worn enough to also be causing movement. In torquing down the axle after that replacement it snapped on the car without the full 340 ft/ lbs of force required to torque appropriately.

Once everything was fresh (hubs / bearings / axles) and it's been problem free since.

Also replaced lower control arms last year while I had everything apart...wasn't a small bill but it was worth it.

Only thing I regret is I didn't change the uprights...I think those are next for peace of mind.

 

What's the cost to change the uprights?

 

~1k per corner for the parts...plus you'll need bearings again but bearings are like $75 a corner.

I do all my own wrenching so IDK what labor would be...if you're starting with an upright that already has a bearing installed it's maybe an hour to R&R it if you have the right tools.

 

For those of you who wrench, the 997 upright is better - stronger, bigger wheel bearing, just need to verify the ABS sensor still works... Porsche moved from a toothed wheel to a mag stripped wheel bearing at some point - but the boss may still be there...

Ray

 

I'm changing my right rear wheel bearing and axle, most likely this weekend. Sunset had a good price on the axle, bearing and wheel nut. The biggest issue was having the correct ball joint removal tool. Turns out, harbor freight sells one that fits just right. It's the right size to get set and hit with an impact wrench. Joint pops without any effort. Saved me a ton of heartache and cuss words.

-td

 

If you search my login name, you will find me droning on and on about suspensions, also talk a little about tools there.

Ray

 

I changed mine at about 38k miles to be on the safe side. They were fine AFAIK, but did it anyway.

 

I've never broken an axle (knock on wood) and that is on a track car putting 600hp/670tq to the wheels. I'm using stock TT/GT2 axles which many guys on Cup cars are running with success. The black axles appear to be very tough.

I have however broken several rear wheel hubs and also a gearbox output shaft. The last hub (the stronger 997 version) I broke only lasted 4K track miles. When you break a hub, general carnage ensues as you wipe out the rear upright, caliper, brake rotor, and the axle. Not exactly a cheap exercise if you add it up. I am currently having custom rear hubs manufactured out of 300M which should remedy the failure of this part. The OEM hubs are die cast parts. 300M is a vacuum arc remelt steel and the hub will be milled out of a 300M forging, same stuff aircraft landing gear is made of for example.

Rear hub (note the broken off "neck" and the stripped out splines)




Gearbox out put shaft shattered under acceleration

[url=https://flic.kr/p/Giabor]

[url=https://flic.kr/p/FtJ8e4]

 

I think it's fair to say your much higher torque loads are a lot harsher on these components compared to our relatively low powered and low torque GT3s powdrhound. What tyres are you running? Hoosiers?

 

275/335 NT01s. I've stayed away from the real sticky stuff which would only accelerate the demise of the hubs and other parts.