NickD

So I've searched quite a bit to see if anyone else has had this problem or something similar and seem to be coming up with blanks.

I get a really nasty vibration that is directly correlated to my speed that starts and stops at random. What I mean is, I'll be doing 60 steadily, slow for traffic, stop and go for a bit, traffic speeds back up to 60 and I have a really nasty, violent vibration. It generally doesn't last long, 30 seconds, not even enough time to get in the right lane and pull over. Or it just reduces to the point where I say to hell with it for now. I'll check it when I get home. This has happened 3 times, with a few months between incidents. I had a set of snow tires on the car when it first happened, I've since put my summer tires on and have had it happen. The vibration does change with the speed of the car but I can't confirm if it stops if I take it out of gear. There seems to be nothing specific that triggers the problem. I thought perhaps one of the calipers was getting hung up but I don't feel a tugging on the wheel when it happens and I don't see any evidence of an overheating brake rotor. Though, I admit, I haven't looked at the rotors until well after it stopped and with the vibration shaking everything it's difficult to tell if it's pulling marginally to one side.

I've done no suspension work to the car, no modifications and I've replaced no parts; there's 70k on the car currently. The engine has been tuned and I do track the car. I was wondering if anyone had any ideas as to what this could be?

TorqueSSter

One of my co-workers is an ex mechanic, and he & I were bouncing this around.

With the track time & mileage on the car, we wonder if you don't have some slop in the suspension bushings or wear in the suspension components. Maybe some deal where the wear/play manages to add up in the worse way at times , giving that vibration, yet stabilizes ( or the worn part moves back into place ) when you slow down. That almost sounds like the "death wobble" scenario that some solid axle 4 wheel drives seem to have.

The other thoughts we had were some sort of a CV issue as they would tend to show vibrations at highway speeds.

I would assume that tire/wheel imbalances and brake issues could be ignored just because those would not go away, at least not to my knowledge & experience.

Anyway, some WAGS to use as a conversation starter.

Please let us know what you find, and good luck !

Britt

NickD

This is along the line of what I have been thinking too. There's got to be something in the suspension worn and perhaps something is triggering it. I've ruled out wheels and brakes (pads/rotors at least) since I swap wheels, rotors and pads for the winter season. I gotta see if maybe I can get a video of it happening and as it goes away too.

andrewcarr1993

iTrader: (5)

I'm pretty sure death wobble can only happen in a vehicle with a front solid axle.

How are your control arm bushings?

NickD

I'm assuming they need replacing at this point. I haven't gotten a good look at them recently, but after the abuse they've taken from the track and from the potholes this past winter, I am sure they are done.

NickD

So I think I know what may be causing this. I think my left front caliper is binding and under certain conditions it partially seizes causing the vibration. The rotors/pad combo I have is more for economy driving, I swap them with a more aggressive set up before I track the car. So I think the cheaper set up has some minor vibration that gets exagerated when the caliper hangs.

I noticed that after a high speed heavy braking I had the clutch in and would normally roll to a gradual stop at low speed (<5mph), but instead I felt the car unnaturally come to a early stop. This went away when the vibration did, indicating that caliper was no longer partially clamping down on the rotor.

I also know on the track that high speed hard braking 100mph+ results in a hard pull to the right. Hard enough to throw me off my line. This could indicate the left caliper not clamping as hard as the right due to binding.

I'm going to buy a rebuild kit for both front calipers and tackle that. I have a track day coming up in about 5 weeks, so hopefully I can get all this done before then and we'll see what happens.

andrewcarr1993

iTrader: (5)

Glad you seem to have found your issue. What's the better pad and rotor combo? Stock because I'd argue that's the best.

NickD

Yep, the better combo is stock rotors and pads.