Help diagnosing metallic scraping noise [Archive] - SR20 Forum

: Help diagnosing metallic scraping noise


thepep
08-25-2002, 08:46 PM
I finally finished my high compression motor swap and got it ready for its first test drive. Started to drive out of the garage and I hear a metallic scraping noise coming from the front wheels, mostly the passenger. It is speed dependent.

Pulled it back into the shop, put it on the lift and took the wheels off. The rotor near the top had a very small groove cut into it. I removed the caliper and looked for a stone or something that could have done this. Didn't see anything. I felt the surface of the break pad and it was smooth. I used brake cleaner on the pads and rotor and bolted it all back up. Took it for another test drive and the same noise.

Brought it back into the shop, took the wheels off again, started the motor and put it into first gear. I could not hear any scraping noises! It appears that the problem occurs when the tire/wheels are weighted.

I talked on the phone to a mechanic friend. He said, among other things, that if the large axle nut were not torqued enough there could be some play which could cause this noise. I don't know if that would be the bearing or the actual axle making the noise. I'm gonna have our mechanic at work take a look at it tomorrow. Any input would be appreciated though. Keep in mind that before the wheels, calipers, rotors and axles were taken off as part of my engine swap, I had absolutely none of these problems so something happened when these things were reinstalled.

Steve

Projnx2000
08-26-2002, 12:40 AM
Originally posted by thepep
It is speed dependent.
It appears that the problem occurs when the tire/wheels are weighted.

By this statement, the wheel bearing s are suspect.
-On a flat road, going straight turn the wheel slightly hard right to unload the R/F wheel bearing and see if the noise goes away. If turning left, should get louder due to loading the R/F side.

Retorqueing (sp) the axle nut, rechecking the pass. axle bracket mount (the 3 12s), and also the backing plate hitting the rotor are also a few other things to check.
Hope this helps.
Chris

thepep
08-26-2002, 08:13 PM
Well, I feel like a complete idiot. It turns out the problem was the dust shield was hitting the rotor. When putting the hub back onto the axles, we grabbed the dust shield and must have bent them just enough that it was touching the rotor.

Bent them back a little and no more noise. Thanks for the opinion.

Steve