Front End Vibration

[Doug]

I am fighting this vibration from the front of our SSEi, I replaced the rack-n-pinion, both outer tie rod ends, brake rotors, tires-tried multiple types and brands, trans and engine mounts, front struts, front upper mounts with bearing plates and tried differant alignment angles. It still vibrates above 60up to 75mph. I road forced the tires each time I replaced them and they are allways less than 10lbs, usually aroung 2-3lbs. Wheels are true, I spun them on the wheel balancer without tires to check. This has been going on for 4 years and I give up. Can the lower control arm bushings cause this???

[00Beast]

a few on here have the issue, and it is different for everyone.

[harrydunn]

I feel your pain. I've tried many things as well to no avail. Going on three years now.

[billberry12]

I did all that too, along with front wheel hubs on both sides. Finally, after replacing both CV axles, it went away. The passanger side CV axle showed no signs of being bad, but it was the last thing I replaced, and it stopped the problem.

[San Juan Cruiser]

This has been an issue for several members and thus far i dont know of a common fix. I dont know if you have tried but if you have acces to a balancer try doing a lugcentric balance rather than hubcentric. I know an oe wheel should balance just fine off of the hub but a different method might yield some better results.

[golfyeti]

The "65-mph shimmy" has been a pet peave for me too. I'm looking at the rear suspension as a possible source now, suspecting now the rear lower control arm bushings -- on back order. I too have replaced a lot except, the rear lower control arm bushings - I replaced the air shocks, shock mounts twice, an end-link adjuster arm, end link bushings recently.. and that specifically help stability a noticible bit. These end-link bushings (moog or energy suspension) are an inexpensive upgrade for handling improvement.

I also get the rear "clunk" over low speed bumbs.

Yesterday though when pulling out of the driveway I slammed the brakes while driving hard in reverse and heard the loudest clank back there! Like something cracked loose or maybe "seated". Weird, for quite sometime during the drive there were no more clunks at low speed and noticibly less shimmy at 65. It felt like new! Didn't last all night, but I was able to reproduce it tonight!

Wouldn't the rear lower control arm bushings be the point under most stress in a hard deceleration in reverse? Could this have temporarirly reset something... indicating that this is where to focus my attention?

Just throwing this out there. I want to hash this out and to nail down this issue once and for all here.

[sco99888]

did you ever change out the wheel bearing?i had vibration in mine and it was the bearing

[golfyeti]

wheel bearings have not been changed -- pretty sure they are fine though - no play that I can detect. It's not so much "vibration" or humming that I am hearing/feeling but rather hearing very loud clunks over cracks in the road at lower speed (and experiencing a shimmy at approx 65 mph that's probably another issue ). There are also rattles that accompany the clunks too, but one thing at a time...

I slam the brakes while in reverse every chance I can now since it works so I know there's a link. I don't always hear the loud "crack" I heard when I first found did this and found it to quiet the clucks. It drives so much quieter for almost a full day now!! My teeth are starting to unclenched a bit now - LOL!

If the new lower control arms don't help I think I'm going to replace the shock mounts for a third time with another choice than Monroe.

I would still like to nail down the cause though. Anyone care to speculate on possible root causes to said clunks and rattles?

[billberry12]

Could you explain why you slam the brakes while backing up? What does that do for the car?
Thanks,
Bill

[renedavila]

i had the same problem, i live in hilly terrain and specialy tend to show up(the vibration)during up-hill curves and change both axles and walla!,no more shimmy,vibration is gone for good.maybe a pothole or a curb made the axle to go out of balance;chek for that...buena suerte!

[harrydunn]

It sounds like wheel bearings and CV axles would be the last things for me to try. The right one was replaced about 2 months ago but no improvement. I have no play in my wheels at all so I would not think it would be wheel bearings. If I knew it would fix it, I guess I would go ahead and replace both wheel bearings and both axles. A bit pricey if you're not sure that will fix it.

[billberry12]

My guess is cv axles. I think your wheel bearings would be making a noticeable noise, and you would have play in the wheels too. Replacing both cv axles finally got my vibration to go away, after trying everything else. I feel your pain. It is very frustrating.

[DR_Gonzo]

I was able to get rid of almost all of my vibration in my car by replacing the rear shocks.

[harrydunn]

I was able to get rid of almost all of my vibration in my car by replacing the rear shocks.

Can you fill us in on the history of your vibration a little bit? I've heard of the rear-shock solution before but have been hesitant to slap new shocks on it and still have issues.

Thanks.

[DR_Gonzo]

I was able to get rid of almost all of my vibration in my car by replacing the rear shocks.

Can you fill us in on the history of your vibration a little bit? I've heard of the rear-shock solution before but have been hesitant to slap new shocks on it and still have issues.

Thanks.

Car had a pretty good vibration starting around 60 mph. It would shake the passenger seat and you could feel it shake in your feet and legs too. The steering wheel didn't really shake much. I don't remember the vibration getting any faster with speed, just move violent.

Hope that makes sense, it's kinda hard to describe a vibration!

[harrydunn]

Interesting. Sounds like what most experience on here, especially the 60-mph part. How many miles are on your Bonneville? What brand are your replacement shocks?

Thanks.

[DR_Gonzo]

Interesting. Sounds like what most experience on here, especially the 60-mph part. How many miles are on your Bonneville? What brand are your replacement shocks?

Thanks.

110K on the car. Replacement shocks are right from the dealership GM parts. It still does have a tiny little bit of a vibration to it, but it is hardly noticeable. The thing really just glides down the road! I'm a big fan of these cars now that I have bought one!

[Newbie2000]

I’m having this exact problem, have replaced passenger axle, pass lower control arm, new rotors and calipers, new drivers side wheel bearing, new sway bar end links, Has new struts in front, n new air shocks in back also,switched front tires to back, it’s still there! It’s at it’s worse at 60 . It’s on the right side, if u turn to the right and give it gas u can feel it bad, like wheel is wobbling? If u turn to the left n give it gas it’s not there, it’s bout gone right at 69-70 mph, and at very low speeds under 50 u can’t feel it , I’m leaning towards the passenger axle shaft even tho I replaced last fall! I got it from advance? It’s killing my wallet this issue!

[Louiej99]

I, too, have the "70MPH" vibration.
I'm thinking it's from the back, not the front. I remember being told if you feel the vibration through the steering wheel it's the front end. If you feel it in the seat of your pants it's the rear end.

[96 SSEi]

Could you explain why you slam the brakes while backing up? What does that do for the car?
Thanks,
Bill

cars with our rear brake assembly use a screw-type adjuster for the p. brake:when you hit the brakes, it adjusts and holds better.