Wheel shimmy

[jzwales]

I have a shimmy in my '95 E34 at 50MPH up to 60 MPH , tires are new and Balance has been checked, alignment done also. One tire guy thought the front left tire was out of round. So he moved it to the rear and the vibaration only increased? Whatam I missing here?

JZ

[MicahO]

Are they the original stock (15" hubcentric) wheels or are they upgrades that will require centering rings?

Also, these cars are terribly sensitive to balance issues, particularly at the front. If they were not dynamically balanced (which means there are balancing weights on both the inside and the outside) they could come up zeros for 'static' balance and still cause a shimmy on your car.

Finally, it's not impossible that one of the new tires has a defect, though you may need a fairly high-end road force balancer (Hunter or the like) to detect the issue?




I have a shimmy in my '95 E34 at 50MPH up to 60 MPH , tires are new and Balance has been checked, alignment done also. One tire guy thought the front left tire was out of round. So he moved it to the rear and the vibaration only increased? Whatam I missing here?

JZ

[jzwales]

Thanks for getting back to me. I do have original wheels, but I've upgraded the tires to Bridgestone r950 performance tires. Perhaps I should go back there and have them verify what kind of balancing they did? However, at 40 mph, they are smooth as glass. At 70 the vibration begins to go away.


Are they the original stock (15" hubcentric) wheels or are they upgrades that will require centering rings?

Also, these cars are terribly sensitive to balance issues, particularly at the front. If they were not dynamically balanced (which means there are balancing weights on both the inside and the outside) they could come up zeros for 'static' balance and still cause a shimmy on your car.

Finally, it's not impossible that one of the new tires has a defect, though you may need a fairly high-end road force balancer (Hunter or the like) to detect the issue?

[632 Regal]

an out of round tire, I had to go back 4 times and still wasn't satisfied...cant get round tires from a place that are just plain too stupid to their own jobs. Anyways you should be able to see how out of round they are when they spinn the tire for a balance, point it out to them.

However your problem seems to be at the same specific speed that signals that your thrust arms are trashed. Try to get round tires first but I dont honestly think you will be satisfied until you change your thrust arms. There is a ton of information regarding thrust arms on this site.

[Martin in Bellevue]

get under there with a prybar & check the bushings for deflection & cracks. If they're a few years old, change 'em. If the ball joints are worn, or deflect when compressed by channellocks, get new thrust arms with bushings already pressed.

[Unregistered]

Had the same problem. 60 mph and again at 130 mph. Tried to get the tracking sorted and track rod arms snapped. Got two new track rods. Problem sorted! Drives like a new car!!

[jplacson]

I had my bushings changed already... but I still have a slight shimmy (well, more like a moderate vibration) at around 60mph. Is this still thrust arm related? BMW didn't recommend an arm replacement, just the bushings.

[Jazzman]

I had my bushings changed already... but I still have a slight shimmy (well, more like a moderate vibration) at around 60mph. Is this still thrust arm related? BMW didn't recommend an arm replacement, just the bushings.

The dealer may have replaced your bushings, bossing, but if the ball joints are shot you will still get that shimmy. You should've replaced the thrust arms with new Lemforders, 750 bushings and ball joints already in.

[632 Regal]

maybe they missed something?

[Stacy (Sydney)]

I had mine bushes replaced, shimmy moved up at speed - from 50 to 70 mph. Replaced tyres- shimmy went away. hhhmmm - maybe its worth only replacing bushes on an e34 when it LOOKS shot ( is torm , lots of visible movement ), if your tires are past the 1/2 way point with wear.

[Aardvark]

Make sure to check for warped brake discs and when the shocks were replaced last. Replacing the latter made my shimmy disappear at the same speed ~50

[Rick L]

If it was the warped brake disc, shouldn't you feel the shimmy when applying the brake? If not, it must be something else...



Make sure to check for warped brake discs and when the shocks were replaced last. Replacing the latter made my shimmy disappear at the same speed ~50