warped rotor?

I have a 97 Regal GS....About 25,000 miles ago i replaced front rotors and ceramic pads.... Rotors cost $30 a piece... Auto store told me they were wagner......After some tome i notice a vibration when braking.... I also noticed a lesser vibration when not braking. Car has been to the shop a few times where the front wheels had to come off.... Ive been told that lug nuts have to be tourqed.... After vibration i had hub replaced, tierods, and struts...... If not tourqed properly can the rotor get warped, causing a vibration even while brakes are not applied?

Yes, the 100 ft-lbs torque is important and can cause the rotor lateral runout problem. However, the lateral run out on most rotors is due to poor quality or installation. Most $25 - $30 rotors will be OK at first and then get flaky. The vibration is common as a result. Try rotors of better quality like Raybestos PG.

BTW - Once the rotors are damaged you may feel the vibrations or imbalance condition even without applying the brakes.

I agree with Bob. The lug nuts and wheel are what hold the rotor on the hub. IF you don't torque the lugs properly, it will allow uneven expansion of the metal the rotors are made of. Over time, this will result in deformation of the rotor and a pulsation, worse when applying the brakes, but possibly still there when brakes are not applied. How you drive will determine whether you can get away with the cheaper rotors. If you are a late braker that waits until the last possible moment , or drive constantly in stop and go traffic, you'd be better off paying the extra money for the better rotors. I've had "cheapo" rotors last 60-70k (60%city-40% highway) when properly installed on a car that isn't abused or constantly stood on it's nose.

I agree with Bob. The lug nuts and wheel are what hold the rotor on the hub. IF you don't torque the lugs properly, it will allow uneven expansion of the metal the rotors are made of. Over time, this will result in deformation of the rotor and a pulsation, worse when applying the brakes, but possibly still there when brakes are not applied. How you drive will determine whether you can get away with the cheaper rotors. If you are a late braker that waits until the last possible moment , or drive constantly in stop and go traffic, you'd be better off paying the extra money for the better rotors. I've had "cheapo" rotors last 60-70k (60%city-40% highway) when properly installed on a car that isn't abused or constantly stood on it's nose.
To add, (geez again!), make sure the hub mounting surface is rust free especially around the studs.

To add, (geez again!), make sure the hub mounting surface is rust free especially around the studs.

maxwedge is right, cleanliness is next to godliness. if you have a bump of contamination causing an uneven surface on the hub and torque a flat surface like a rotor to 100lbs against it somethings got to give. since the rotor is subject to extreme heating and cooling cycles it's going to give first, conforming to the uneven surface, causing runout. factory specs for torque on wheel nuts is as little as 77lbs but most tire shops now hand check the torque to 100lbs or more to try to crush or otherwise mitigate contamination problems when a wire brush and some solvent would work better.

and watch your torque pattern, tighten all the lugs to about 50lbs then follow the torque pattern 3 to 4 times after that, tightning each lug no more then 10 or 15lbs (about a quarter turn) each time.

no disc brakes on the truck to the left<<<<<< but it does have a hole in the floorboard on the passenger side in case you feel the need to help out.

The GM wheel nut torque spec for a '97 and up Grand Prix is 100 ft-lbs and should be done manually with a torque wrench.

One thing you definitely do not want to do is over-torque beyond 100 ft-lbs because the stud will break off and/or it will cause rotor warpage. Just about all aftermarket alloy wheel manufacturers recommend the following torque patterns. Of course, we follow the 5 bolt pattern:

http://i5.photobucket.com/albums/y186/lizzywiz/pattern.gif

If the rotors are truly Wagner then the boxes will have Wagner written on them. Next to bendix Wagner is one of the best quality aftermarket brake manufacturers out there. If they are actually white box rotors instead of Wagners then the rotors should have been cut before they were put on. A cross hatch nondirectional cut is recomended. If the rotors were also dropped at any time it will cause them to be out of round which also will give you a vibration. Where did you get the rotors? If they came from Autozone or another chain store there is a good chance they are not wagners. The "parts professionals" they hire will tell you whatever they have to to make sure you buy from them. A wagner box has their logo in orange with blue lettering and have a part number of BD125507 for the front and BD125506 for the rear. Average counter price of 50.00 each.

If the rotors are truly Wagner then the boxes will have Wagner written on them. Next to bendix Wagner is one of the best quality aftermarket brake manufacturers out there. If they are actually white box rotors instead of Wagners then the rotors should have been cut before they were put on. A cross hatch nondirectional cut is recomended. If the rotors were also dropped at any time it will cause them to be out of round which also will give you a vibration. Where did you get the rotors? If they came from Autozone or another chain store there is a good chance they are not wagners. The "parts professionals" they hire will tell you whatever they have to to make sure you buy from them. A wagner box has their logo in orange with blue lettering and have a part number of BD125507 for the front and BD125506 for the rear. Average counter price of 50.00 each.

I agree. There is no way you're gonna get Wagners for $30.00. Probably the AZ ValueCraft or Duralast Basic cheapies. My Raybestos Professional Grade ran $55 per rotor.