Vibration...I'm lost
 

Around 55-70 mph I have a vibration in my seat. From 35+ mph I have a vibration in the steering wheel. When I lightly press the brakes the vibration gets worse in the steering wheel and goes away with more pressure on the brake pedal. So I changed the front rotors, replaced outer tie rod ends, replaced front wheel bearings, had front wheels balanced, got a 4 wheel alignment, and the vibration is still there. U joints look fine so I don't think that could be it. The rear wheel bearings seem fine too. I don't know what else it could be because everything is tightened and I cant find anything visual to lead me to the problem. Any help would be appreciated.

If you can feel it in the steering wheel, it is most likely something in the front end. Did you rotate the tires? did it change? Everything looks OK up front?

Yea I had em rotated and balanced the same day I got it aligned.

Didn't see anything about ball joints in there, did the alignment shop check them while on rack? Were the ctrl arm bushings checked? Motor mounts?

I had two bent rims on my car that caused the vibration. They we going up/down while on wheel balancer. Fortunately I was at my buddy shop and he was cool enough to show me the issue. Not sure if it had been another shop if they whould have given me that info, or if they would have just thrown them back on w/o saying anything.....

It prob says what the vehicle is on a sig....however I'm usually on the cell on here. You're on the right track, just have to troubleshoot some more. That's the fun or owning cars :-)

I'll check the ball joints and control arm bushings this weekend. Yesterday I added some more air to my rear tires. I was running 32 psi. Now I'm running 35 and today the vibration in my seat was very much more noticeable. Not sure if that really has anything to do with whats going on but it did make me think maybe I have a slightly bent rim.

Reputable shops will do roadforce and check rims for being bent. If you pay any attention to a wheel while it is being balanced, you'll see its bent... :\

well I've only dealt with this shop twice but I went there because of all the good things I heard about em. What are some things that could cause vibration in the rear?

driveline/pinion angle, bent axle, warped rotors, bearings... wheels/tires...

also, check this out: click me

i had pretty much the same issue they describe in there, and it was fixed when TDP installed one of their mainshafts...hopefully it doesn't come to that for you, though, it's an expensive fix, no doubt...they did mine while it was getting rebuilt.

How can I check my driveline/pinion angle? I just had an alignment done but I dont know if thats included in it or not.

https://ls1tech.com/forums/17376638-post50.html

from
https://ls1tech.com/forums/suspensio...ano-parts.html

Looking at that thread it definitely seems like my pinion angle could be off. I'm gonna try and change the angle this weekend and see if anything changes. I know that the rear brake rotors have never been changed since I bought the car so that could be playing a part in the vibration too. I'll check the ball joints and pinion angle this weekend and post back what I find.

There is no OEM pinion angle adjustment possible AFAIK. You would have to have an aftermarket torque arm...

Correct. There is not. You need an aftermarket ADJUSTABLE torque arm to do so.

He asked about possible vibrations from the rear, so I listed them :D He is not lowered so his angle is probably fine (does not hurt to check though)