Last week, my car suddenly started making a horrible scraping noise form the left rear wheel area. It is speed dependent, and it gets louder when you turn right, and much quieter when you turn left. It also refuses to make any noise when it is up on a lift, which is maddening.
My first thought was that one of the plastic covers on the bottom of the car had come loose and was scraping the road surface, but that wasn't the case. Second thought was a rock in the brake caliper, but on inspection there were no rocks.
I had recently had things apart back there when I did some rear suspension work, and had an issue with the retention springs on the e-brake assembly getting bent. I forgot to back the adjustment off before trying to pull rear brake
rotor
, and it jammed, refusing to go either back in, or come out without a fight. After eventually having to pry it off, it wasn't wanting to center properly, so initially I thought that was the culprit and replaced slightly bent retention springs, which are apparently made from plutonium given their price. That didn't work. I even ran the car with the e-brakes removed once as a trouble shooting step, and the sound was still there, although reduced in volume.
When I went to reassemble everything, suddenly there was axle grease sprayed on the rear suspension, and I found a leaky CV axle boot. Pulled everything apart to get to that and then in a fit of frustration just decided to replace everything that I thought could be a problem. So I did all new rear rotors, pads, ebrake shoes, and a new wheel bearing on that side, as that had some play in it and it seemed like the time to replace it as I was already all the way in there. rear brakes were due for a change anyway, so I just bit the bullet a few months early. Inspection of the cv axle showed the boot wasn't torn, it was just leaking around the factory seal, so I replaced the seal for now. It seems to move smoothly, and a mechanic friend who looked at it didn't see any problems.
None of that worked. There is still a horribly loud scraping sound coming from the left rear wheel area.
So this morning I spoke to a local
Porsche
Specialist, and described the symptoms. He is fairly convinced it is a bad wheel hub from my description, and would like me to bring it by for confirmation. I can't understand how what is effectively one solid chunk of metal could go bad, or how it would cause such a horrible noise if it did. Anyone ever heard of that?
Excuse if this sounds so elementary...did you check the brake dust shield on the inboard side of the
rotor
? I had one bent on an
S2000
once that sounded horrible. Easy fix to just bend out.
Yes sir, that was actually thought #1b in conjunction with rock. It's been checked repeatedly at this point.
I should note that this noise started suddenly on a drive to the grocery store. The car was driven several hundred miles the day prior, with no issues. Then halfway to Wegmans, the noise starts out of nowhere.
Hub bearings? If they go bad they may be noisy only under load although that may not always be the case.
