brake upgrade/wheel shimmy

[rogue325]

I recently upgraded to performance slotted/ drilled brakes all the way around the car. After Installation I noticed a slight shimmy in the steering wheel when tapping the brakes at higher speeds 50mph +. Could I have improperly tightened the rotor(which doesn't seem likely with only the One L-wrench screw point) or is it more likely i Have a defective rotor.

[terrysumner]

I recently upgraded to performance slotted/ drilled brakes all the way around the car. After Installation I noticed a slight shimmy in the steering wheel when tapping the brakes at higher speeds 50mph +. Could I have improperly tightened the rotor(which doesn't seem likely with only the One L-wrench screw point) or is it more likely i Have a defective rotor.

You could have gotten a bad rotor right out of the box...wouldn't be the first time I've seen that happen. Could also maybe have gotten a piece of junk under the rotor when you installed it? Easy to have happen if you don't clean the area good. How did you break the rotors in..hopefully you didn't overheat them and one or both warped a bit. They're not blue are they?

Terry

[nathancarter]

That hex screw on the rotor is only a convenience to hold the rotor in place during installation anyway. It's really the lug bolts that hold the rotor to the hub.

Raise each of the corners and spin the wheels by hand. Watch, feel, and listen for anything unusual - any scraping noises, or if the brakes seem to "catch" at a certain point in the wheel revolution.

I second Terry's opinions - either a little piece of debris between the rotor and the hub, or a rotor that's bad out of the box. MAYBE your lug bolts are torqued improperly... on my old MR2, unevenly torqued lugs would cause the rotors to warp a bit and make all sorts of vibrations, but I don't think the E46 lugs are that sensitive to variances in torque.

[rogue325]

thanks guys, when I installed the rotors i did clean away any debris that looked like it might cause a problem. After install i felt the shimmy immediatly during the rode test so i dont think i warped them(hope). Now i'm leaning more towards a defective part. I've done my fair share of brake jobs in the past but this would be my first on a bimmer. Are the wheels in the front that sensitive to torque? I have OEM wheels that i torque to touch by hand, unfortunately I don't own a torque wrench.