dan212

I have had this happen to me once or twice.. I always have track pads on my car and I think my well bedded rotors sometimes accumulated some brake scrud (very technical term) caused by more casual street driving .. It only happened a few times over the last couple of years. Its very disconcerting for sure..

I found that a few good hard hammers on the brakes to really get them hot cleared the problem.. Did you try that? The general all-american solution.. Hammer or kick something and it gets fixed I guess

dan

Camber

I usually notice it when the car has been resting a while, and most often when I'm changing direction (forward/reverse). It doesn't happen all the time, but it definitely happens, and has on both of my 996 GT3's.

LVDell

The good news is I will be at the track in a few fews and can really get on them

AllanJ

Did you put that flat spring doohickey in there? If not, that's another potential reason for the movement.

I'm itching to get back on the track. It's like a drug. It has only been a week and I've got the shakes.

LVDell

Yup, it's in there as well. You are talking about the spring retainer clip correct?

Serge944

I don't get the shakes - I just start treating every turn on the street as a race track. It's been a month and a half here...

AllanJ

Yep. That doohickey.

Don't you have track days to go to every other week? Follow Mooty around and you'll be tracking more than going to work.

LVDell

Those days are behind me. Tracking about every other weekend and then moving on to club racing. Now, I decided to, wait for it, think about this a little more rationally and concluded that I could have a fatter bank account and more capital than I could dream of if I stopped racing as well as going to the track 1-2 times a month! I have since built a 5K playground for the kids, a 40K home theater (almost complete) and yet still have money to spend. Shhh, don't tell anybody

BY the way, back to the issue. I just got done spending some more time in the garage with the car and went back over everything a few more times and the only thing I found was I missed one rotor set screw of the two required for the front driver side. Maybe that was it? Not sure. Still need to go drive it and test.

I actually ran by the dealer this morning and talked to my tech about it while I was up there for some work on the other car and he said it could probably be the shims not being installed when brake pressure is released just before stopping. We'll see.

Stay tuned.......

Camber

I can't imagine it's the missing screw. They're there to hold the rotor on when the tire isn't mounted. Once those five lug bolts are secured, those screws aren't doing anything.

AllanJ

I'm only using 1 screw per rotor (I drilled my own hole for the ATE Cayenne rotors) and no clunks under braking on my car.

...but you never know.... easy thing to check out.

LVDell

I can't imagine it's the screw either but the rotor did move easily with only one of the two installed. But I agree, once the wheel it bolted on, there is no chance for movement.

Will drive it tomorrow afternoon (hopefully).

iLLM3

Dell, I had a clunk as well and it wound up being the backing plate on the caliper being loose just from wear and tear (the anti chatter plate to the pads?) .. And a bolt in the lower ball joint was loose too, that was more of a clunk noise over a bump though...

LVDell

Probably won't drive the car until this saturday to coffee so I'll post back then.

spare tire

Ther common thing to look for is the drop link bolt to the sway bar as they often loosen, but that has been mentioned and excluded. Be sure to check the upper bolt for the drop link where it connects to the strut. Not as common to get loose but easy if that is the problem.

LVDell

Checked both top and bottom of the drop link. I am beginning to think it pad banging at release of pressure against the cotter pin.