Mark Finley

OK, this is really strange, and a little scary. Twice today, as I was coming to a stop, my car's front end started rocking back and forth. No vibration or noise, but a very severe rocking. It only happens every once in a while, and maybe only when I'm braking on a slight curve. My struts might be a little weak, but I can't find anything else that has come apart down there.

Please give me a hint of where to look for the problem!
Thanks,
Mark
1985 Camaro

Mark Finley

BTW, I just checked my ball joints, and they don't seem abnormal at all. Could it be a blown strut, and the wheels are just bouncing around?

VegasZ

Sounds like your front brake rotors are warped. Time to have them turned and smoothed out.

Mark Finley

I've had rotors warp before, and this feels entirely different. My experience with rotors is you feel is slowing dowm from 70MPH to 40MPH, but nothing at slower speeds. This is exactly opposite. It's fine until about 15 MPH, and then a violent bucking and lurching.

Thanks for the post though,
Mark

tanmanski

u sure it's brake related? I agree with your bad rotor assesment, I've always noticed that worst at higher braking speeds. Your sig doesnt tell us anything about your car, is it manual or auto? what engine? Reason I ask is I believe a bad tq converter lock up solonoid could cause the "violent bucking & lurching as you come to a stop. If the tq converter remains "locked" as you stop it will try to kill the engine & act like a manual tranny being brought to a stop stil in gear. Any indications your engine RPM is abnormally low during these events?

Mark Finley

Very interesting theory, I'll have to check out the tach during the next episode. It's not the first thing that comes to mind while you are concentrating on keeping the car in the correct lane.
It's an 85 sport coupe with a 2.8 in it. Auto tranny, nothing special.
I'm still thinking it's a suspension problem, but I can't find anything wrong except the struts. They are shot, and I'm going to change those tomorrow to see if that helps.
TO describe the problem in greater detail, the lurching and bucking is more side to side, not front to back. It's like somebody is outside the car trying to rock the car until it rolls over. Never felt such a thing before.

AL SS590 M6

Check all of your control arm bushings. Even the back ones. Check your sway bar end links and mounting bushings too.

Mark Finley

I'll check those. Thanks for the tip. I was concentrating on the front of the car, but I guess it could be in the back..

In the meantime, I replaced my front struts on Saturday. They were SHOT! One didn't have enough pressure in it to support the weight of it's own piston. Boy, does the car ride differently now...
No problems in the last 48 hours, but I'll know by the end of the week if the problem is gone. If it hasn't come back by then, I'll proclaim it cured.

Mark

Mark Finley

OK, not cured. It did the problem slightly today. Not change in RPM, its almo certainly a suspention problem. I took my foot off the brake and put it back on, and the s rocking stopped. I felt the steering wheel moving back and forth in my hand while it was happening.

Any ideas?