PontiacBonnevilleClub.com

Working on ironing out all the quirks of the new bonneville, took it on the freeway for the first time and noticed above 50 mph the steering wheel / front begins to shimmy/vibrate - not a violent shake. Recently replaced the struts and there was no excess steering part movement. Also, the front motor mount was falling apart and was shaking at idle, fixed that. I rebalanced the tires, no change. I noticed this is a common problem, but I don't see any real solutions. I dont want to start throwing parts around if someone can guide me in the right direction. Thanks.

Was the rest of your front end shaken down?

dematka wrote:Working on ironing out all the quirks of the new bonneville, took it on the freeway for the first time and noticed above 50 mph the steering wheel / front begins to shimmy/vibrate - not a violent shake. Recently replaced the struts and there was no excess steering part movement. Also, the front motor mount was falling apart and was shaking at idle, fixed that. I rebalanced the tires, no change. I noticed this is a common problem, but I don't see any real solutions. I dont want to start throwing parts around if someone can guide me in the right direction. Thanks.

I have been trying to figure this problem out for many years. Just about the only thing I haven't replaced in the front is stuts and strut mounts. 190,000 miles on my car. I wonder if a GXP strut brace would help, hmmmm.

If you can live with it I would say save yourself a lot of money chasing it like I did. You find speeds at which it's less obvious.

I've noticed this is a HUGE problem with these cars...etc. But no one has a SURE FIRE solution that solved THEIR problem. Being I don't know the most about these cars I was hoping someone could point in a direction - oh well, time to go my own direction. My struts were bad anyway, so they got replaced, helped the ride, not the shimmy. Next plan is to replace the side motor mounts - they are horribly rotten, then road force balance the tires. After that, there isn't much left but something vibrating in the trans??? My car only has 137k miles, but the previous owner put on tires which I don't categorize as high quality, but they balanced out without much weight so I don't really think the road force balancing will do much but gotta start with the cheapest fixes... Thanks for all the feedback...

I have the same shake. I've changed rims and tires and that didn't help so I went back to the rims and tires I have now. I've checked inner and outer tie rods. Ball joints. Thought the steering shaft but was told that wouldn't do it by the dealership. I'm thinking maybe the rack and pinion. Don't the ssei models have something like a magnasteer? If so can that be malfunctioning?

dematka wrote:I've noticed this is a HUGE problem with these cars...etc. But no one has a SURE FIRE solution that solved THEIR problem. Being I don't know the most about these cars I was hoping someone could point in a direction - oh well, time to go my own direction. My struts were bad anyway, so they got replaced, helped the ride, not the shimmy. Next plan is to replace the side motor mounts - they are horribly rotten, then road force balance the tires. After that, there isn't much left but something vibrating in the trans??? My car only has 137k miles, but the previous owner put on tires which I don't categorize as high quality, but they balanced out without much weight so I don't really think the road force balancing will do much but gotta start with the cheapest fixes... Thanks for all the feedback...

ive had this same problem in my o3 bad, after changing parts to no avail, i found...assuming front end is tight and wheels arent bent or anything. clean hub surface, inner and outer rotor surface, and wheel flange mounting surface, balance tires, and torgue lug nuts to 100 ft lbs, cured my problems for good. try it!

Problem solved - road force balanced. Didn't think it would work but it did.

dematka wrote:Problem solved - road force balanced. Didn't think it would work but it did.

But now when you rotate your tires theres a chance it will come back.

I had the very same problem, shake at highway speeds. After trying everything a friend told me it was the clutch in the lock-up torque converter. Found a low mileage wreck at the local junkyard and replaced the transmission and installed a new converter. Now it's smooth as silk. If you don't replace the transmission make sure to flush the old one out, as the particles from the clutch can get into the transmission and cause more problems later on. Try everything else first because this is a lot of work.