I'm trying to chase a "Shimmy" at 80 mph in my car. I've put on two sets of different brand new tires, t sets of new wheels, had countless balances, 2 alignments and yet I still get a shake at 80 mph.

The only thing I can think of left to do is balance the tires and wheels on the car and see which wheels is thre problem, then troubleshoot the problem from there.

Something is slightly out of tollerance. Maybe warped, etc.

Can anyone give me an idea if this is possible?

I also live in Charlotte, NC. There may be some place local here with all the race stuff that goes on.

Thanks and Happy Holiday.

 

Try changing the location of your wheels. There may be a wheel or tire that is out of round, and placing it on the back should help.

What brand of tires did you buy? I've had problems with most brands of tires, with the exception of Michelin. Best tires you can buy, in my opinion.

You may also check your alignment and tire pressure.

There is sometimes a combination of several small things that are contributing to the problem.

 

I've put on two sets of different brand new tires, two sets of new wheels, had countless balances, 2 alignments.

And yes I rotated them also.

 

I can recall many 1980s-era BMW 320i's having a chronic shimmy that regular balancing would not cure. One recommendation was to ensure all alignment settings were within specs.
There are definintely some balancing machines out there that balance wheels while they're on the car.

 

I've had 2 alignments, both done at the Lexus dealership.

I can feel it change, come and go with accelleration and de-acceleration. Such as when the car is being pushed forward by the driving wheels and when it is being slowed when I let off the gas a little. Like it's not just speed related, but whether your body is being pushed back into the seat during acceleration or being pulled out of the seat when slowing down.

I don't know if that explains it well enough, but I can also move the wheel a little and it will diminish.

It doesn't act like it will shake at 80 no matter what, speed up, slow down, change lanes, different asphalt, etc. It seems to matter, but not until around 80 mph. and it doesn't matter if I have a passenger or not.

Thanks.

 

This "shimmy" is it coming through the steering wheel or felt in the car at that particular speed?
How many miles on your car? What RPM range is this? Does it persist above 80 MPH?

On a past car, it developed a vibration and noise above 72 but was not present in the same RPM range in lower gears. In my situation it was two areas...differential bearing was going and the final gear in the tranny was suspected to be on it's way out.

Some things to check: motor mount, tranny mount, differntial mounts and if this may be a U-joint issue I dunno how the drive shaft is on the LS. May not hurt to re-torque the various suspension braces as per the factory manual.