92 Bonneville Front End Shimmy

[J Wikoff]

My 92 Bonneville has a slight shimmy. It's been around for quite some time, and I thought it was just the tires. I got new tires a couple weeks ago, and the shimmy did not change. It's not very severe, just kinda annoying. It's in the front end, though the steering wheel doesn't really want to go back and forth side to side much, it's more of an up/down kinda feel. It shows up at 40-50 mph, and calms down some above 75. I thought about having a bent wheel, but the tire guys didn't say anything. I can feel it in the steering wheel, and in general in the body too.

[scorpion]

I had the same problem with my 99 ssei and it was a cv shaft. Don't know which one cuz I replaced both of them.
Not saying that's your problem. But just an idea where to look

[J Wikoff]

Well, the left CV has had a pinhole in the boot for years, and very slowly splooges grease. I dabbed with JB weld more recently, and it seems to be holding.

[GRRRR8]

Check engine mounts 1st. A worn or sagging engine mount will cause this issue and eventually lead to a damaged CV shaft.

[J Wikoff]

They've actually all been replaced during an engine swap that post-dates the shimmy.

[scorpion]

I still say replace cv shafts

[J Wikoff]

Update:
I've replaced the CVs, ball joints, tie rods (inner and outer), wheel bearings, endlinks, and calipers, and the shimmy persists. I'm going to take it in for an alignment and ask them to double check the wheel balance and if there are any bent wheels.

It comes around 50 mph, and fades around 70. And it seems to flare up a little when off the gas and coasting. I've ordered new ignition coils to hopefully rule out a slight misfire. Mine are MSD's that are maybe 10 years old that I bought used.

Beyond that, any more ideas?

[roman1978]

I think you have a bad balancing or bent wheel