hey guys

new forum member here.

several months ago, i upgraded to my brakes with the Q45's. In the test run after the installation my car would shake after 35mph. i realized i didn't tighten the bolt from the caliper to the spindle hard enough. after tightening the bolt, it was fine.

now, after 3-4 months, my car is shaking badly beyond the speeds of 40mph. i checked my brakes and they're fine. the bolts are tight and i don't see any problems. sometimes there is no shaking. other times the shaking occurs after 15 mins of driving.

the shaking is pretty bad. i see the steering wheel and the auto trans shaking up and down. i feel like i'm sitting on 5 massage chairs.

please help. if i can't find a solution, i'll end up putting my stock brakes back on.

 

Ok theres a few things to check. First does it shake when you press the brakes only or does it shake all the time?

If it's during braking only, take it a shop to get checked out. You could have bad/warped rotors and they may be able to cut them down if they aren't to worn already. Although I would just recommend new ones over cutting anyways.

If it's all the time there could be other problems related to the wheels:
- wheels are out of balance - shop can easily fix that
- bad wheel bearings
- bad tie rod/tie rod ends

To check the wheel bearings and tie rods just jack your front wheels off the ground, and shake each wheel by hand side to side, and up and down. There shouldn't be any slop when you're doing this.

If it does have slop side to side only, chances are you have a bad tie rod/tie rod end (get these replaced immediatly as it's very dangerous...you'll need an alignment after this too)

But if it has slop in an up and down movement most likely you have a bad wheel bearing...if it has slop both ways, same thing...or it's the wheel bearing and/or tie rods.

Now if those are all fine, check your motor/trans mounts for cracks or any other type or wear or problem. And always check for bent suspension parts.

Anyways, hope this helps. Let us know how things go.

 

the shaking only occurs while cruising above 40mph, not when i am braking.

one thing to note is that the current shaking is same as the one i experienced when the caliper and spindle was not bolted correctly.

i will check for the things listed above. thanks.

 

try this: take a wheel off, get a jackstand with a screwdriver taped or vice gripped to it and put the tip of the screwdriver on the face of the brake rotor with about a 1-2mm gap(so its not touching). then spin the rotor. the rotor should not contact the tip at all. if it does u have a warped rotor, which will cause a shimmy. u have to change ur pads too at this point because they wear with the rotor so if the rotor was warped then the pad will be worn in an odd pattern which will affect the new rotor and ruin it.

if the rotor is not warped, check to make sure the pads r dragging constantly/consistently across the rotor.

if thats not the problem check the steering rack bushings to see if they're worn. almost every 240 ive worked on had bad rack bushings which caused slushy steering response and in most cases a shimmy.

hope that helps get u started.