Player0

I got the 944T back from the shop and I noticed some grinding noises from the rear right wheel. I took it apart today and I'm pretty sure it's the brakes. The bearing and axle are solid. I measured the run out and it's 0.003" on front side and 0.002" on the rear side. The rotors are 23.1mm thick so still within limits afaik. It's been sitting for a while so this might be why it's more noticeable?

I've ordered some rotors as I wanted some backups on hand anyway. Is it safe to run a rotor making that kind of noise at the track? It drives and handles fine, it just makes that grinding wub wub wub while rolling forward, even if the brakes aren't applied.

I haven't checked the hub run out or removed the pads/caliper yet to 100% rule other things out. The brakes were bled at the shop as well. They also removed the parking brakes, backing plates, and anything related. So they were definitely in there.

But the scraping noise definitely coincides with the high spot on the rotor. So if it really is just the brakes, is this a safety concern?

Dutch944

I've had a scraping noise at some point as well from the rear brakes, but this was due to improper mounting of the parking brake-pads

jerome951

I'd suggest you have the shop pull the rotor just to check. I've never heard of a rotor making that kind of noise solely from being slightly warped. The rotor may also not be seated squarely on the hub.

Alternatively, back off the parking brake adjuster to see if the noise goes away.

Assuming everything checks out fine, I wouldn't be concerned about running that rotor on the track unless you get pulsing under hard braking.

Player0

I went to check the hub itself so I finally had a chance to take the pads off. Still made the noise. Uh oh. So I took the caliper off. Still made the noise. Now I'm thinking... ****... hub or transmission I just had rebuilt. So took the rotor off... and a parking brake spring fell out of it. Silence at last.

I had just had the car in the shop and they had removed the parking brake and all related components. Not sure how but somehow a spring got caught up in the rotor. I don't think they had test drove it.

So not the brake pads, so questions above are mostly moot. Still an awful lot of run out on these rotors but with no noticeable noise or shaking. But good to know they're okay for another season.