Since I frequently track a heavy, heavy street car, it's common to hear me say "I got 99 problems and brakes are all of them." The Brembos have been very, very good, but brakes still take the most abuse of anything, and are the most likely part of the package to have issues. So when I heard a metal scraping sound from the rear (once per wheel revolution), I really thought it was a rotor/deposit issue or something with the caliper. My first go-to solution, crossing my fingers and hope it fixes itself, didn't work unfortunately. So I pulled off the rear wheel, had a friend help and we examined the rear disks and applied brake pressure with the rear raised. Nothing presented itself, but I eventually spent a Saturday removing the rotors and having them turned at O'Reilly. While I was at it, I had a set of my used DBA slotted front rotors turned as well.
Unfortunately, it fixed nothing, the sound remained, and I was out $60 for the turning and most of my Saturday afternoon. So... it probably wasn't brakes. Emphasizing once again: this is why I don't work on cars.
On Monday I did what I should have done in the beginning, I took it to specialist shop Awesome Z, and they identified the problem as being a worn driver's-side rear wheel bearing. Aside from consumables like brakes and tires, this is the first real mechanical failure resulting (probably) from doing track events. It's inevitable, so no complaints here. Track driving is abusive, so after a year and a half of this, I was due. They said the passenger-side rear wheel bearing didn't have any play in it, so it could be a fine for years or it could be on it's last legs, but it's hard to tell. Wheel bearings are too pricey to treat as preventative maintenance and replace early.
It's all fixed, and the shop also did an alignment and dialed in a bit more negative camber, which will be interesting to try.
As I said, I had my DBA front rotors turned. I pulled these off the car in November, hoping to have them refinished and swap them back on in the spring. But there's a ton of tiny hairline thermal cracks. Are these toast?