bad wheel bearings?

[slantscamp]

hey guys, while i was putting on my new rotors with new bearings i noticed one of them spins smoothly but when i put on my second rotor it makes a light kind of thunking noise. if that makes sense. it sounded like it was coming from the outside bearing, so i went back to the store and got another new one. but it still thunks lighty when i spin the rotor. so then i switch sides of the car to make sure it wasnt something with the spindle.. that checked out ok. the rotors i bought had races in them already. so i changed the outer race today. i havent tried it with the new outer race. i was thinking of stopping at the store and picking up yet another inner bearing also, maybe that one was bad. does anyone know what would cause this. or have any experience with it? i really want to get my car back together and this is all thats holding me up.

 

[69signetv8]

Sounds like you have done just about everything! You said your spindle is fine when you swapped sides? If so...did the light thunk stay with the rotor and bearing when you switched sides? I can only think that if the old bearing had over heated it may have put your spindle out of round. You could also check it with outside calipers or a micometer. Did you try the bearing just by itself on the spindle and give it a spin? I can't beleive two new different rotors/bearings would have the same problem.

Just my thoughts buds:munky2:

 

[63dartman]

I'm with signet, there is a possibility that that you got a bad rotor. I would put a gauge on it and see if it's true or not. It wouldn't suprise me if you you got a bum replacement part. Is the testing with or without the brake hardware installed? I would remove the calipers and hardware to eliminate any brake pad rubbing. Also, why were you putting in new rotors and bearings? Did you have issues before the replacements?

 

[slantscamp]

they are brand new rotors, and brand new bearings. i installed them with the calipers off so i dont think anything is hitting. when i switched sides. the problem followed the rotor. so i at least know its the rotor or the bearings. if the 2nd set of new bearings doesnt fix it today, im gonna take back the rotor. thanks guys.