Hey guys, i have changed my rotors, pads, and compression rod bushings. I get this huge vibration only when i brake at speeds over 70. Under that speed my brakes are completely fine, and nothing shudders. What do you guys think it could be?

have the rotors turned...problem solved.

if the vibration is in the steering wheel, the problem is in the fronts

if the pedal vibrates, the problem is in the rears

if everything vibrates.....do the math

^ +1 on that, i just change the rotors on my girls car cuz it vibrated on the steering wheel like crazy on the freeway when i would brake, changed the rotors and BAMM problem solved!

I just changed the rotors yesterday, and i still have the problem. I put in OC autoports drilled and slotted rotors. the vibration is crazy. Even the passengers can feel it.

u know what i just changed my front rotors, and i still have the oem rear rotors. I think thats whats causing the problem.

I doubt this is what your problem is. I have the same issue. I jack the car up and spin the wheel and I can hear the rubbing off and on of the pads on the rotors on the front wheels. I found some things called brake rotor shims. I think I'm gonna get some. I got my rotors resurfaced for 30 bux and they still shudder. They are only like a few months old. I've been getting the vibe really since I changed them. I believe it must be rotor/hub runout. Too bad I'm committed to another 40 bux at least. Check this thread where this dude, Q45tech explained them.

if its not your rear rotors, have all your wheels rebalanced

cool, thanks for the advise

+1 good advice everyone.

Sounds like your rotors are warped. Once that is fixed, then check tires.

can i still resurface the rotors if they are warped? or should i just get new ones. my mechanic told me that my rear rotors can be turned a bunch of times?

if he says they can be turned, then turn them, imo. but you might not be able to next time cause they have to be at a certain thickness. also, the more times you turn them, the more suceptable they will be to warping becuase they are thinner. sounds like that is your problem. if that isnt it, check to make sure you dont have any clumps of mud or something in your wheels before you have them rebalanced, that can cause a vibration too

4drmadness, please be sure to let us know if machining your rotors solves the problem.

If you are extremely demanding and rich [or can do it yourself] I fine touch up front rotors everytime I rotate and balance my tires since the wheels are off anyway. I just remove 0.001" per side from rotors since there is 0.03937" of metal to the wear limit . Forces me to clean entire braking system of wear dust and measure pads looking for any asymetrical wear.

Just some of the things I do every 90 days to maintain in proper as NEW mechanical condition.

I had this exact problem on an older car before i purchased my g35. The mechanic told me that it was caused by defects in tires or driving on poorly balanced tired creating flat spot. Sure enough, I put new tires on and the problem never came back after 40,000 miles.

You sure? Sounds like the shudder you got must have been whether you were braking or not. 4drmadness' shudder (and mine) occurs only during braking.