Rotors

[darkcherrymetallic]

So I replaced my front rotors this past weekend while doing a brake job for my 2002 grand prix gtp. It just dawned on me that one of my rims is not totally flush on the rotor. All the other three rims are flush on the rotor. When I push on the tire (mounted on the rotor/hub) it ever so slightly moves. I tried to visually see if the rim is not making contact with the rotor, but couldn't find anything noticable. I have driven this car on the freeway at 70 mph and the car nor steering wheels does not shake.

I was just wondering if anyone know if this would eventually become a bigger problem down the line. If so, what can I use on the rotor or rim to correct the problem? a coating of something? apply some sort of tape? I guess one area of the rim is not making contact with the rotor by a minute amount.

Thanks.

[Tech II]

It just dawned on me that one of my rims is not totally flush on the rotor


You have me totally confused......

[olopezm]

Are you sure it's the rotor? Maybe a suspension component has worn out???

How about swapping the rotors to see if the problem does the same?

I don't know, I would think that this problem could cause the lugs to stress more than usual, it happened to my family when I was 12 years old and we were traveling on our 88 cutlass eurosport, the wheel just went out flying the good thing is no one was hurt.

Are you using a torque wrench? Did you use an air driven wrench to install the lug nuts? I know from other users in the forum these tools can strip the threads when used to install the nuts on the bolts/lugs.

Oscar.

[Tech II]

Olopezm, you actually understand what he is talking about? Explain it to moi.....

" When I push on the tire (mounted on the rotor/hub) it ever so slightly moves."

Is he talking about a loose hub/bearing?

[rkvons]

Originally Posted by Tech II

Olopezm, you actually understand what he is talking about? Explain it to moi.....

" When I push on the tire (mounted on the rotor/hub) it ever so slightly moves."

Is he talking about a loose hub/bearing?

When you put your wheel on, it has to fit over the hub and then slide inward until it hits flat against the rotor. Then you tighten the lug nuts. Maybe what is happening is the wheel is bottoming out against the hub before it makes contact with the rotor. Just guessing here. The parts of interest to me would be, are they OEM wheels? Is it an OEM hub? What is the distance from the rotor surface to the outer end of the hub? Stuff like that. Perhaps it is making contact with the rotor, but moves around because the bearing is going out.

[olopezm]

Tech II: I understand his problem could be similar to when you are reinstalling wheel lug nuts by hand; some are tight some aren't and the wheel wiggles all around.

I agree to inspect the wheel hubs too or maybe the rotor isn't properly machined. I remember some users having problems with new rotors, however I don't remember which brand they used.

Oscar.

[darkcherrymetallic]

Yes. The hub is the original as are the tire rims. I have a 40th anniversary gtp so my rims are slightly different from the normal gtp ( i think). My rotors are new. I did check to see if it is the rotor that is not sitting flushly on the hub, but I don't think this is the problem. I hand tighten the lug nuts to the rotor on the hub and it felt secured. I couldn't wiggle or nudge the rotor at all. However, when I have the tire tighten to specs at 100 ft/lb in the proper order with my torque wrenches I can wiggle the tire just a tiny bit by one of the bolt. By wiggle I mean if I push at the tire, it wiggles just a tiny bit inward towards the body of the car. Not every part of my rim is designed to make contact with the top of the rotor's hat/hub, so i observed at all the contact areas but couldn't find any obvious places where the contact points are not touching each other. However, as stated above when I push on the tire it tilts/wiggle inward just a tiny bit. Thanks for all of your suggestions.

[olopezm]

You could try putting some grease or fresh paint on the back of the rim where it should make contact with the rotor and install it. That way you'll be sure where is not making contact and if the rotor is the problem.

I would check the hub bearings for play, maybe it's just a coincidence. Put the wheels in the air and hold each wheel at the 12 and 6 o'clock positions, move it back and forth and see if you have any play. You can have an assistant to move it while you take a look at the back of the wheel.

Oscar.

[darkcherrymetallic]

Olopezm...I believe you are on the right path. I checked online for symptoms of a wheel bearing failure and the description does match what I have. I did jack up my car and with one hand on top of the tire and the other hand on the bottom of the tire I was able to "rock" the tire by just a tiny bit when I push with one hand while pulling with the other hand. It is just a very slight and tiny rock like I've said in my earlier post. How much "rocking" is normal if at all?

This past weekend I noticed for the first time that when I backed out of my parking space while making a sharp turn I heard a "grinding" noise. For a while everytime I made a right turn the grinding noise would come on. I don't hear it now when making turns. The noise is not a screeching sound. I did check my power steering fluid and it is at the appropriate level.

I believe it has got to be something with my wheel bearings. Later today I will drive around and make figure eights to see if that grinding noise that I heard before would come back on. My question to anyone is...is it acceptable to have a little rocking with the wheel bearing at all? Mine is so ever small.

Thanks.

[Tech II]

There should be NO play at all....

[olopezm]

"Rock the wheel" that was the exact phrase I was looking for!

I can't find the exact tolerance but it's only a few thousands of an inch, which in case you have an actual gauge to measure the movement of the hub, the actual reading will be bigger than the actual tolerance in order to be able to feel it.

I can't remember if users have reported a grinding sound with bad hub bearings, but they have said listening to humming noises (mine did the same) and sometimes an always on ABS and/or Trac off light. What I do recall is they sometimes listen the humming sound coming from the right side and the bad bearing turned out to be the opposite one.

Hmm... Will you be able to drive the car? Yes; is it safe? NO. The bad bearing might go out within a week, a month or a year (somebody actually drove the car for 3 years until he scrapped it) and you can end up loosing the tire while driving. Costing about $90 dlls I don't think is worth the risk, you can replace them yourself just make sure THEY ARE the cause of your problem.

Oscar.