Grinding sound from left rear wheel- CCW
 

I thought I would post over here first since this is about my CCW drag wheels.

Anyway, went racing last night for the first time this year, and was hoping to get some answers to questions over the winter about tire size and things. Came away with more questions than answers

Long story short, I changed to a new tire size this year. Put a new set of MT ET streets on the car.

First run, my rollstop is not working for some unknown reason so I can't get a good burnout anyway.

Spins like hell off the line and not a good run. Stop in pits and check fuse. Fuse good. Come right back around and run again. Same burnout, crappy run, but this time I get a grinding noise from the back left tire/wheel area at the end of the track (1/8th mile).
I stop at the end ot the turn around and check for .....something...mmmm, not really sure what I was hoping to find.
Drive back slowly to the pits. It starts to sound again and then goes away. Kinda sounds like the wheel might be bent and scraping against the spindle or brake caliper. Maybe and brake pads scraping against the rotor or something. It stops after 50 ft or so, and I put the car up on the trailer and bring it home. Get back to the shop and jack up the rear and take the left tire off. I see some scarp marks on the inside of the rim about where the spindle would line up. Don't see any wheel weights.

Hoping to look more into it today

Ok, so here is my question.

Should the CCW wheels and new tires be balanced? I had the wheels/tires put together this winter, thought I told them to balanced them. Maybe I threw the weights off on the first run, because I don't see any weights on them.

Would this make the wheel wobble enough to grind against the spindle? Probably only got to 75-80 MPH, but that's fast enough for a good vibration.

What else could be causing the grinding noise? I don't know enough about the u-joints in a half shaft to know if they could be causing the sound. Any thought on that area?

I hope to get a chance tomorrow to dig into the car more. Maybe put my street tires back on and take it for a quick drive.


Thanks for any suggestions or guidance you guys can give me.

I can tell you that I had a similar problem at the drag strip...all of a sudden mine made an awful rubbing noise if I turned the wheel to the left..turned out to be a bad posi unit...my first hint was when the car did a crappy burnout...I had someone look and on my second burnout it was only spinning one wheel...good luck..

That happen to me two years ago, and I thought of that too, right after the sound show up. But this was a different sound than that. Defineatly a sound like occasional scraping, not all the time. Kinda timed with the tire rotation.
Maybe I'll put the street tires back on, do a burnout and watch for tire marks to see if both whells are spinning just to be sure.

But thanks for the suggestion.

Are these the 16" CCW Drag Package? If they are and you never ran them on your car, you need to modify the cap on the ball joint. Beat it down SLOWLY with a ball peen (sp) hammer. I did that AND ground the bottom of the control arm a touch because when I launched the wheel would rub that area. :cheers:

Yes these are the 16" CCW drag pack, but I have already done the grinding earlier whn I ran 16" firebeird rims. Besides, I have run these CCW wheels for the last year with no problems.

What is new is the tires this year. Mounted them on the same old rims (CCW's above) but first time on the car together.

I am leaning toward rim was bent maybe when tires were mounted, and therefore wobbles a bit. Though I did not here any grinding at first (loading & unloading the car on the trailer, driving up to tech inspection, driving it up to the line and first burnout &run, repeat for second run). Sound only showed up right about the time I slowed to make the turn off at the end of the second run. Actually, right about in the turn. Which could go along with Fuzzy's thought about the rear end bad.

What about a wheel bearing?

That's a good thought. Any kind of test for that? Shouldn't there be play in the tire if I grab two sides and shake it back and forth while jacked up?
Which there wasn't, but I would have thought so.

I don't know how to test for the bearing. That said the few I have read about here have noticed the grinding under load while making a turn.

Good place to check. Thanks for the input. You may be on to something there, and I will check that out. Hope that's all it is, and not the rear end. Wasn't looking forward to pulling that thing out again.

I get little rocks caught between the cap and rim sometimes makes noise and scraps up the inside of the wheel.i bet thats what happened.

Update, Pulled the CCW rim off and found srape marks around the inside of the rim about where the spindle would be. I have run these rims for over a year now without any problems, but for some reason this time is must have scraped.

Which leads me to believe 2 things:
Either the rim is bent a little or;
the bearing is loose and the rim tilted on the spindle.

If the second occurred, the noise should have been constent. Instead the noise was more like occasional as the wheel made revolutions.

I then put my street rims/tires back on and went for a short ride. Everything sounded good. No noise.

I think that I will take it into my mechanic to check the bearings/ spindles and everything back there to make sure of no damage, but otherwise I am going to chalk it up to a bad wheel. Or the the wheel/tire is so out of balance that it was causing some wobble/ bounce in the rotation to cause the itermittent scraping.

Any other thoughts?

If you are talking the rim cap. That's not the case for me- I don't have no stinking caps! :D

I meant the spindle cap.:D

When you had the new tires did the rims end up getting switched from one side to the other?

there are slight variations in the rims which could cause ot to rub if the rims were switched, try switching the rims from one side to the othernad see if it still makes the noise


Was the car lowered or raised back up in between using the CCWs? Lowering the ride height of the car will affect how the rims fit the car.

Look for rub marks on the calipers, could be from stick-on wheel weights rubbing the caliper. another option wouls be to dab some paint on the existing rub marks to see if they are fresh or old:cheers:

That could be the case.

No

The noise only happen after the third run of the day. If it were wheel weights, I would have heard that right away when I was loading the car. Unless the wheel weights came loose during that run and caught up in the caliper or spindle near the end of that run, when the wheel was rotaing at a high speed.

Thanks

This is an old post, but I am having a similar issue on mine..

HawkI, my 92 convertible makes a repetitive scrape occasionally under acceleration. Not necessarily rapid acceleration, but just speeding up. If I let off of the gas, it stops. I have pulled the wheel and I don't see or feel anything wrong.

I have had the car throw a code briefly for and ASR issue, but the code then disappeared. I know that your problem was on a track and mine is for regular driving, but I was hoping that you may have some insight... Speed sensor maybe??

U-joint on that side