2000 Buick Le Sabre - Shimmy between 45 and 50 mph

I have been to a few different repair shops for my 2000 Buick Le Sabre shimmy problem with no luck. I wonder if anyone can help? I have a really bad shimmy, while accelerating between 45 and 50 mph, and it seems worse on an upgrade. Past 50 mph, it smooths out. Over the past several months, mechanics have checked the balance of my tires and rotated them, done front end alignment, rear alignment, replaced the right lower control arm, the right sway bar link and the right wheel hub. Still no luck, so it came down to the determination that it must be a bad tire. Now I have 4 new tires (it was soon time to get them anyway), and I still have the shimmy. What else can we look for? My local mechanics seems stumped. I have not taken it to a Buick dealership, however…so costly!

@ShellRod

Is this a front wheel drive?

It could be a defective balancer on the longer CV axleshaft

Yes, front wheel drive.

Just wild guessing a bit, but what about the possibility of a bad motor/transmission mount or a faulty CV joint?

Still wild guessing a bit more, maybe this is an engine performance issue related to the MAF sensor or an air leak in the intake tract.

I’d be looking at the axle too if you ruled out tires, bent wheels, and front end parts.

I second the recommendation to have the CV joints (both inner and outer) checked, as a 13 year old FWD car with these symptoms could have bad CV joints.

I will pursue the CV joints with my mechanic…hopefully he will know what they are! Thank you all, I will post results.

Have someone check to make sure you don’t have a warped or bent rim. Putting them on a balancing machine and spinning them up, you could see it wobble laterally. It could also be crap behind the rotor causing the tire not to sit flush.

Thank you folks for your input! Had both left and right CV axles replaced today, and NO MORE SHIMMY! My mechanic, in his defense, did consider them, and had inspected them, but saw nothing visually wrong with them. Once removed, nothing still appeared to be “wrong” with them, all but for a slight leak on the left one at the boot? Anyway, he went ahead and pulled them and changed them, and I am a happy camper. Thanks again, all, for your willingness to post suggestions.

@ShellRod

Congratulations!

And thanks for posting back