STEERING WHEEL WOBBLE AT 50 mph

**starship1701a** · 05-01-2018, 02:09 PM

been happening for a while now... while normal acceleration upon hitting 50 mph the steering wheel wobbles alot... after 50 the wobble stops... Just had my 8 serviced at a very good local mechanic, turned front rotors, repaired bearings on top of front passenger shock, balanced both wheels and 4 wheel alignment yesterday, but today still wobbles...
I was told that my steering box had alot of "play", could this be the culprit? but why only at a certain speed??

**ChrisFuture8** · 05-01-2018, 02:32 PM

Have you checked the usual places, Star? Upper and lower control arm bushing for signs of cracks/tears? Do you know if your front tires may have flat spots?

**8eights** · 05-01-2018, 02:48 PM

Upper control arm bushings.

**starship1701a** · 05-01-2018, 05:20 PM

Originally Posted by 8eights

Upper control arm bushings.

of course all of the UCA and associated bushings were checked and re-checked... all good and no play...

thus the mystery...

- - - Updated - - -

Originally Posted by ChrisFuture8

Have you checked the usual places, Star? Upper and lower control arm bushing for signs of cracks/tears? Do you know if your front tires may have flat spots?

no tire anomalies were noticed by the mechanic...

**8eights** · 05-01-2018, 05:48 PM

Were the uppers preloaded before installed unless they are Spherical?

**starship1701a** · 05-01-2018, 06:46 PM

Originally Posted by 8eights

Were the uppers preloaded before installed unless they are Spherical?

i was willing to change the UCA but the mech said that it was NOT required... in fact, i already changed them about 6 years ago...

**8eights** · 05-01-2018, 07:06 PM

Try putting your stock wheels on the front to see if it goes away, If it doesn't go away, it's a bushing, Can you tell which one is shaking?

**TxGR8White** · 05-01-2018, 07:33 PM

Control arms. You can check them visually, but you need a second person. Have your helper watch the front wheel as you drive at about 15-20 mph and come to a complete quick stop. If the wheel moves toward the back of the wheel opening, you have control arm issues.

**starship1701a** · 05-01-2018, 07:50 PM

Originally Posted by TxGR8White

Control arms. You can check them visually, but you need a second person. Have your helper watch the front wheel as you drive at about 15-20 mph and come to a complete quick stop. If the wheel moves toward the back of the wheel opening, you have control arm issues.

yes that sounds like a very good test!! thank you... ill even have it video taped...

**cartoonz** · 05-01-2018, 09:01 PM

Most likely control arms but if all else fails to provide a fix, check your rims. I had one that was slightly out of true and, even thought it balanced ok, it produced similar symptoms.

**mr1173** · 05-01-2018, 09:54 PM

Everyone here will point you to UCAs and other suspension components... But actual source of vibrations is always you wheels.
Good control arms help to damp those vibrations through rubber bushings. If your bushings are worn out you will heave excessive movement of the suspension components allowing harmonic vibrations to multiply at certain conditions and become noticeable. On the other hand some people may also suggest to replace UCA bushings with spherical ones, but it will only hide the problem by stiffening the suspension - the whole car becomes a huge damper.
So, if you don't have any play in suspension - take a closer look at your wheels and tires. Even a good looking tire can have internal cord damage. If you can, swap your front wheels with known good ones to test.

**Dr. T** · 05-02-2018, 12:30 AM

Originally Posted by starship1701a

i was willing to change the UCA but the mech said that it was NOT required... in fact, i already changed them about 6 years ago...

This is the key phrase here...”6 years ago”. You’re lucky to get 1-2 yrs with the stock UCA bushings before they get soft and cause the dreaded wobble! But they’re only a couple bucks and 30 min/side to replace...

**1959terry** · 05-02-2018, 12:27 PM

I Hope Timm won't mind however check the attached link. Lots of useful stuff.

https://www.meeknet.co.uk/e31/E31_Shimmy.htm

**starship1701a** · 05-02-2018, 01:02 PM

Originally Posted by cartoonz

Most likely control arms but if all else fails to provide a fix, check your rims. I had one that was slightly out of true and, even thought it balanced ok, it produced similar symptoms.

ok yes... my front pass rim had a dent on the inside edge i was told, he tried to right it as much as he could them balanced both rims...

i feel its my rim/brakes as well, but not discounting the UCA bushings...

thank you!

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Originally Posted by 1959terry

I Hope Timm won't mind however check the attached link. Lots of useful stuff.

https://www.meeknet.co.uk/e31/E31_Shimmy.htm

wow! tons of interesting stuff!!

thank you