Strange front end shimmy when turning
08-28-2002, 06:45 PM
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Strange front end shimmy when turning
After replacing almost the entire front suspension sans steering knuckles, wheel bearings, drop links, and swaybars, I have a new thing that appeared since I did all of this work (I noticed it before I replaced the control arms and ball joints, but I figured it was part of that problem)...whenever going at high speeds (over 50 or so) and I turn either a slight left or right, I feel a mild shimmy/vibration in the front end. Its not nerve racking, but I would like to get everything straightened out with this car.
So, I can only think of two things that may be causing it: loose wheel bearing (they make no noise though) or the tire is rubbing against the fender at higher speeds because of the downforce (the car was dropped over an inch w/ 400# springs and coilovers) since before I did all of the work). I noticed that the front fenders could be rolled as there is paint missing from the spot where the tire would be under the fender in a turn, but I didn't notice any rubber on it when I checked it a minute ago (it is raining though).
Any other thoughts on this? Anything I could check? TIA,
So, I can only think of two things that may be causing it: loose wheel bearing (they make no noise though) or the tire is rubbing against the fender at higher speeds because of the downforce (the car was dropped over an inch w/ 400# springs and coilovers) since before I did all of the work). I noticed that the front fenders could be rolled as there is paint missing from the spot where the tire would be under the fender in a turn, but I didn't notice any rubber on it when I checked it a minute ago (it is raining though).
Any other thoughts on this? Anything I could check? TIA,
08-28-2002, 06:52 PM
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My money's on wheel bearing - I am having the same problem right now with the right front... just haven't had time to install the new ones yet. I knew they were going because I've had to tighten the bearing down a small amount before every event this year.
What about your alignment - did you get it sorted out after all the work. If you're having this problem on both sides, it may be a toe problem.
Good Luck!
What about your alignment - did you get it sorted out after all the work. If you're having this problem on both sides, it may be a toe problem.
Good Luck!
08-28-2002, 07:14 PM
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[quote]Originally posted by Skip:
<strong>My money's on wheel bearing - I am having the same problem right now with the right front... just haven't had time to install the new ones yet. I knew they were going because I've had to tighten the bearing down a small amount before every event this year.
What about your alignment - did you get it sorted out after all the work. If you're having this problem on both sides, it may be a toe problem.
Good Luck!</strong><hr></blockquote>
I actually had to tighten the passenger's side wheel bearing because the wheel had noticable play in it a while ago. I am thinking this may be it. I am getting an alignment tomorrow (finally found a shop that can do it). Skip...the old steel a-arms...they don't have the caster eccentric that the later arms have...does this mean that caster is fixed or is there some other adjustment that I am ignorant about?
<strong>My money's on wheel bearing - I am having the same problem right now with the right front... just haven't had time to install the new ones yet. I knew they were going because I've had to tighten the bearing down a small amount before every event this year.
What about your alignment - did you get it sorted out after all the work. If you're having this problem on both sides, it may be a toe problem.
Good Luck!</strong><hr></blockquote>
I actually had to tighten the passenger's side wheel bearing because the wheel had noticable play in it a while ago. I am thinking this may be it. I am getting an alignment tomorrow (finally found a shop that can do it). Skip...the old steel a-arms...they don't have the caster eccentric that the later arms have...does this mean that caster is fixed or is there some other adjustment that I am ignorant about?
08-28-2002, 08:33 PM
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The caster is now only adjustable by the amount of slide the rear bushing carrier allows - the same as all early 944's had. While less, is still adequate. I have a bit more range with the adjustable camber/caster plates.
Skip
Skip
08-28-2002, 09:59 PM
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[quote]Originally posted by keith:
<strong>Bent wheel? (you have the same crappy ones I've got)
Hey Riblets, why aren't you driving down to autocross with us?</strong><hr></blockquote>
Wheels are straight as far as I can tell. I don't know how they would have gotten bent as I haven't hit any sizable holes, curbs, etc. since I got them. Check my post on the DC/VA/NC thread. I may come down if I can find a place to crash saturday night.
<strong>Bent wheel? (you have the same crappy ones I've got)
Hey Riblets, why aren't you driving down to autocross with us?</strong><hr></blockquote>
Wheels are straight as far as I can tell. I don't know how they would have gotten bent as I haven't hit any sizable holes, curbs, etc. since I got them. Check my post on the DC/VA/NC thread. I may come down if I can find a place to crash saturday night.
08-29-2002, 02:16 AM
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I had a similar problem after installing a set of M030 spindles and hubs, and new bearings and new rotors. My initial shimmy was diagnosed as out of balance wheels and tires (18" Porsche Technology wheels). After rebalancing 95% of the shimmy at 55-65 was gone, but I still had a little bit. I reset the bearing play and it's now 99% OK at those speeds.
However... I've developed another problem. If I apply the brakes easily from a relatively slow speed of 30-40 mph I can feel (at times) a little pulsing in the brake pedal and (at times) a slight pulling in the steering wheel. Any thoughts what this could be? The rotors were brand new Porsche 993TT with Kokeln aluminum hats. I certainly don't think they are warped after only a few easy street miles!
Could it be a slightly loose ball joint or A-arm bushing? I've got 87,000 on the car and was thinking of changing them. Thoughts anyone?
However... I've developed another problem. If I apply the brakes easily from a relatively slow speed of 30-40 mph I can feel (at times) a little pulsing in the brake pedal and (at times) a slight pulling in the steering wheel. Any thoughts what this could be? The rotors were brand new Porsche 993TT with Kokeln aluminum hats. I certainly don't think they are warped after only a few easy street miles!
Could it be a slightly loose ball joint or A-arm bushing? I've got 87,000 on the car and was thinking of changing them. Thoughts anyone?
