Opinions on Front End Shimmy

LarryC

LarryC

Curator of #10105275
After 30 years I have picked up a slight front end shimmy at speeds above 65 mph. I am thinking front tie rod ball joints, and maybe front wheel bearings. Also, I suppose the control arm bushings could come into “play” as well as the lower ball joints.

I am looking for second (and third, and fourth, and Nth) opinions. Comments on front suspension re-building are also welcome!
 
www.gsp9700.com

First thing that comes to mind is wheel balance.

See if there is a local shop that has a Hunter GSP 9700---IMO their results more than justify the slighter higher price.
 
Dan, thanks. I was wondering if anyone had an opinion!

These are brand new Sumi's on Daytonas. Normally I would think it was balnace issue, too. But the vertical balance is the smoothest that I have ever felt. It appears to be side-to-side oscillation with a square wave pattern rather than the mostly vertical sinusoidal vibration of a wheel balance issue. Very faint but annoying wheel shake.

Nothing that a complete front end re-build won't fix. But I was hoping to learn something, like, which part is the main culprit.
 
Have you ever replaced your struts?

My '80 had a vibration that I only noticed at highway speeds. Replacing the tires helped some (the old ones were starting to crack from age), but when I put in a set of KYBs that I got from Summit there was a profound difference. Much tighter handling and smooth as butter on the highway. I must have been having a small amount of wheel hop at speed that made everything seem loose and "nervous".

Might also want to check that your wheels are mounted squarely on the hub centers. If they're off a bit you'll feel it more at some speeds than others, as you hit the resonant frequency of the springs.

Good luck!
John
 
JRucker said:
My '80 had a vibration that I only noticed at highway speeds. Replacing the tires helped some (the old ones were starting to crack from age), but when I put in a set of KYBs that I got from Summit there was a profound difference. Much tighter handling and smooth as butter on the highway. I must have been having a small amount of wheel hop at speed that made everything seem loose and "nervous".

Might also want to check that your wheels are mounted squarely on the hub centers. If they're off a bit you'll feel it more at some speeds than others, as you hit the resonant frequency of the springs.

Good luck!
John
Click to expand...

John,
Thanks. The struts are new. The tires are new. The Daytonas are refinished and checked. But I will check that they have centered correctly. You never know.

Then its on to the long term search I guess. The truth is in there somewhere.
 
how are your rotors

I had a vibration issue as well, new tires balanced a couple times, new struts, new hubs, rims mounted squarely (used the Steve H. method), all helped to improve things but the finallie was replacing the front rotors. One was warped slightley. Couldn't really feel anything while braking, but with the x up on the stands you could feel the resistance while spinning the wheel by hand. Its worth a look at the least be it a long shot :)
 
That's a possibility. I noticed a drag at one spot, but just about every vehicle I have ever checked had a slight drag at one tiny spot of the turn. Worth a look, though.
Thanks.
 
I have the same problem

Hey guys I haven't posted on xweb very often but I've been having a similar problem with my 86'
It happens about 65 and gets worse as you go faster. It is just a little side to side wiggle in the steering wheel. I can't find any play in the tie rod ends or ball joints and the shocks are KYB Gas Adjust that the PO installed a few years ago. I'd be interested to see what other people find related to this problem. I've lossened recentered and retorqued the front wheels, I think I may try rotating the tires around and seeing if it changes.
In the mean time I'll just hang on to the wheel with a death grip and mash the throttle.
-Caleb in Northcountry NY, Formerly in Ithaca
 
Caleb, thanks for saving me some time, probably.

I haven't gotten into mine yet, but your problems sounds very familiar. So maybe it is time to do a little checking on the rotors. My experience is that rotors tend to show up as a slight vibration on braking. But who knows. Still worth a look, though.
 
I'm going to do an experiment...

I think I have one or two very slightly bent rims and I noticed yesterday that one of them is on the front. I'll rotate them around today and I'll check and see if the rotors drag real bad in one spot. The rotors are still a bit pitted as the car sat for a couple years before I put it on the road in July so I may turn them or replace them while it's off the road i for the winter.
 
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