PontiacBonnevilleClub.com

I've been battling the 65-75 shimmy for the last 60k without success. I've scoured this forum as well as many others and can't seem to get rid of it. I'm about out of ideas, so I figured I'd post here to see if there is something I overlooked.

In order:
1) Wheel balancing - made it better (although not gone) for about 6 months, slowly started getting worse.
2) Front transmission mount - made it better, but not by much.
3) Both Wheel Hubs - no difference
4) Sway bar end links - it almost completely disappeared after this, but came back after a couple months.
5) New Shocks & Struts - returned it to about where it was when I fist noticed it. Slowly got worse over the next few months
a.) Car was aligned
b.) Wheels and tires were rotated an balanced
6a) New cv shafts.
6b) New outer Tie Rod Ends - this improved it a little bit, but not that much

I am at a loss as to what it could be. Everything under the car is new. Is it possible that the rotors aren't balanced? The brakes don't pulsate, but the shimmy is worse if I brake in between ~68-75 (where the shimmy is the most noticeable.) I have also noticed it seems to be the worst when I am in that speed range and going up a fairly steep grade.

TIA

Your is not an uncommon complaint, and many have gone through the list of things like you have, without a firm solution. Ther was a TSB that replacing the lower control arm bushings may help. I think one member tried that, without it making a large difference. Others have tried the Hunter Road Force Balancer without much luck, too. I believe rrounds vibration went away when his tranny was rebuilt.

dmleonard,

Do you have the chrome "swoopies" or the Good Year RSA's? Can't tell your year and trim from your sig. I ask because I have been hunting down this issue for more than 60K too and that's what I have been running.

I swore for years it coundn't be the tires or a bad wheel balancing as I had mine rebalanced 3 times. I have replaced most of the parts you mentioned with similar minor changes/improvments. I got back to suspecting flawed tires recently (out of round or broken belts)

So a couple of weeks ago I invested in new winter tires and while as I was at it bought new high-end winter allow rims, which look great and make seaonal swapping easy. 85-90% of the shimmey went away. And at one of my recent shop inspections they noted a loose front ball joint. Wonder now if that ball joint wear was caused by unbalanced wheels and is now the cause of the last 15%.

But I must admit that I still think there is somethng else than just unbalanced wheels because that shimmy can still be felt always right in that speed range 65-70. Aerodynamics maybe, because I notice wind direction will shift the shimmy speed range.

My advise to you is to check ball joints and try out a whole new set of wheels and tires, if just for a test drive.

I have a sneaking suspicion that much of it is caused by control arm bushings as well, like was mentioned about the TSB. I have a set of balanced Bridgstone Blizzak tires on '93 gold crosslace rims for the '03 during winter and still get the shimmy even with those rims and tires. Tie rods are tight, ball joints are good, wheel bearings are good, brakes are good, transmission is NEW ( OE for 2003, never installed ) with less then 10,000 miles on it and still have the shimmy at about 65 - 75. The only other thing I can think of it being is the control arm bushings, and at 172,000 miles, that could very well be it for out '03.

golfyeti wrote:dmleonard,

Do you have the chrome "swoopies" or the Good Year RSA's? Can't tell your year and trim from your sig. I ask because I have been hunting down this issue for more than 60K too and that's what I have been running.

I swore for years it coundn't be the tires or a bad wheel balancing as I had mine rebalanced 3 times. I have replaced most of the parts you mentioned with similar minor changes/improvments. I got back to suspecting flawed tires recently (out of round or broken belts)

So a couple of weeks ago I invested in new winter tires and while as I was at it bought new high-end winter allow rims, which look great and make seaonal swapping easy. 85-90% of the shimmey went away. And at one of my recent shop inspections they noted a loose front ball joint. Wonder now if that ball joint wear was caused by unbalanced wheels and is now the cause of the last 15%.

But I must admit that I still think there is somethng else than just unbalanced wheels because that shimmy can still be felt always right in that speed range 65-70. Aerodynamics maybe, because I notice wind direction will shift the shimmy speed range.

My advise to you is to check ball joints and try out a whole new set of wheels and tires, if just for a test drive.

I don't have the swoopies. This is now on its third set of tires, so I doubt it is that. I also bought this car from my father-in-law and he had a separate set of winter rims and blizzaks for it. It did it for him as well on both sets.

I did run across the link below while doing some more searching last night, but I've stuck waaaay too much into this car already and think I'd rather take my lumps and live with the shimmy before I put new control arms on. I would put new control arm bushings in, but with my luck, I'd do that only to find out I should have put the new model control arms in.

http://www.justanswer.com/questions/2kw ... neville-se

Thanks for the replies - looks like I'll throw in the towel and deal with it.

My dealer replaced both control arms per the TSB under my warranty but that didn't help with my 02 SSEI. I Tried everything on your list including new tires and having them road force balanced, found that corrected most of it but not all. After having my rotors turned it cleared it up for me but it came back after a month or so. I never noticed a shimmy while breaking but that seemed to have fixed it for me for a while, guess I should have just replaced the rotors. I ended up ordering a new set of rotors and pads but sold the car before I ever had a chance to install them. This is a cheap fix if it helps. I pulled my rotors and took them to a local garage to have them turned and it cost me $15.00 per rotor. It you try it and it works you should go ahead and order a new set because they will warp again and it will likely return.

Good luck with it

dmleonard wrote:

golfyeti wrote:dmleonard,

Thanks for the replies - looks like I'll throw in the towel and deal with it.

I had a problem with imbalance showing up at certain high speeds in the 65 range and giving a brake uneveness if applied. It went away when I replaced the calipers. I suspect a caliper tended to drag and heated the rotor. And the rotor heated tended to warp slightly giving a tap, tap, tap effect as the high point went through the rotor and pads. I even tried stopping with the parking brake on an uphill slope to see if one front rotor was warm from the drag.

Actually I replaced calipers, pads OEM level not heavy metallic, and high end Raybestos rotors.