Ok, so my friend and I just changed the rear pads and rotors on my 03 WRX. Everything went fine and the brakes work great and everything, but now when I make tight right hand turns we hear a grinding noise from the left rear wheel. We went back to my friends house and pulled everything back apart and made sure it was all tight and put it back and it's better, but it still makes noise. My only guess thus far is that the dust shield might have gotten bent somehow and is rubbing against the back over the rotor. I can't figure out what else might cause it.

Anybody have any other ideas as to what could cause it? It wasn't doing this before we changed the pads.


Thanks,
Mark

 

I would put my money on the dust shield theory. I had this same problem, only on hard left turns with the noise coming from the right rear wheel. After a few months of this, I figured it was a wheel bearing on its last leg caused by stress from negative camber. I ordered the bearing and packings, and started the process of changing them. After removing the rotor, I noticed a bare metal spot on the dust shield and the innermost ring of the rotor (the e-brake drum) was bare also. Looking closer, I saw that the shield was slightly bent inward. A few taps with a ball peen hammer to get the shield back in place, and no more noise since then. The bent shield is commonly caused by trying to remove the rotor by hammering them from the back, rather than using the bolthole-press method to remove them. You end up hitting the shield into the rotor with misplaced hammer blows.

Check this and let me know what you come up with.

 

Thanks for the advice.

It actually started doing this on both sides today...

We took it apart again today and checked the dust shield to see if it was out of place and it seemed fine. We even tapped it back a little with a mallet to see if it would help. What was happening is the exact same thing you mentioned. At the very bottom of the shield under the ebrake shoes is where it was rubbing. There is a ridge that runs around the dust shield that lines up with a ring that's cut out of the rotor (probably to seal in the dust from the ebrake shoes...or something) and it looks like they machined the rotors wrong. The ring section on the rotor was too high and it was sitting too close to the shield so whenever I made tight corners it was putting just enough pressure on the rotor to rub against the dust shield. My buddy grinded them down with a dye grinder (sp?) and it's not making that noise anymore, but I'm probably going to get some new rotors that aren't crappy.

Tip of the day: Don't buy your Subaru rotors at Autozone.

The only reason I did was because I work there and get a discount. It was a mistake.



-Mark