bergx7

For the 997.1 guys (non-CL), do any of you replace bearings or hubs as a preventative measure? I am thinking about refreshing the suspension along with some new goodies and wonder if it would be a good idea to replace hub/bearings while I am in there. There are a few horror stories on the 996 board of failures though I think they use a different design...

TIA

powdrhound

996 and 997 GT2/3/TT use the same hubs and bearings. I've broken several rear hubs and there is a lot of collateral damage every time one fails as you wipe out the rear hub, axle, caliper, rotor, and usually the upright. Normally $5K+ in damage. If you have PCCBs, do the math. I'm not aware of any cars that had these fail unless they were driven very hard with sticky tires and stiff suspensions. In my applications, I'm running a very stiff Cup style suspension with 1500lb springs and put down over 670 ft.lbs to the rear wheels with sticky tires. With the car being driven at the limit, I'm breaking rear hubs about every 2000-2500 track miles. It's basically an annual replacement. As a result I had some rear hubs custom made out of 300M VAR (vacuum remelt steel - same material aircraft landing gear is made of). They are also Cryo and heat treated for an ultimate loading at close to 200% of the OEM hubs. They are not cheap at $2600 per pair but do provide peace of mind. Interestingly I've not had any bearing issues.

[url=https://flic.kr/p/MzJ351]







[url=https://flic.kr/p/LNhcJ5]

audipwr1

Those some crazy hubs right there

bergx7

Yea those are beautiful work!

Anybody else change hubs/bearings on the regular that doesn't put out as much power or run as much tire as powdrhound? It's rare I say this but my car is much slower than yours so looking for folks more within the design envelope of an N/A car on R compounds.

powdrhound

On heavily tracked cars, many guys change out bearing and hubs on a regular basis, maybe every 40 track hours or so. Check with Mooty, I think he changes his on a regular basis.

mooty

when i used to do 40 track day a year on 996gt3, all four bearings are repalced every year

audipwr1

My spec boxster gets new wheel bearings every season

spiller

The higher torque applications of GT2/turbo would have a lot to do with hub failures one would think?

bergx7

Thanks and leave the hubs alone?

mooty

I change both hub and bearing same time. i dont think it's necessary but i do it anywyas

AudiOn19s

+1. I had bearings go bad 2 years ago in the rear and I replaced bearings only..then started to fight issues with bearings going out much more frequently than they should have.

Finally replaced bearings and hubs both over this past winter (axles too) and they are still solid as a rock and showing no signs of wear. In looking at the hubs it looks like there was wear on the hub too that was causing play / heat in the bearing likely causing them to fail prematurely.

The next thing to consider unfortunately while you've got it all apart is if it's time to replace axles too. Slippery Slope....

zweebach

I kept getting a soft brake pedal and thought I might have bearing run-out issue.
I replaced front bearings but those turned out not to be the problem. It was just a brake pad/spring retainer issue.
I damaged a front wheel carrier during the bearing removal process which was an expensive mistake. Front bearings did not show signs of significant wear, so I did not dig into the rear bearings. Car has 20,000 miles and around a third of those are track.

audipwr1

Yeah I think if you running car super hard on slicks it's more an issue - otherwise the hub and bearing are pretty stout

bergx7

Is there a good way to diagnose bearing/hub health? Car has 42k miles on it with some track time on V710's (aggressive r compound but not quite slick) including Sebring (bumpy). Car feels fine. Want to be proactive but not wasteful

ngng

when i replace my hubs i also do bearings, the cost is trivial at that point. i've had a few issues with bearings manifest as pad knockback.