After Alignment, new tires, and balance - get shimmy at 70mph+?

phoenix_iii · 03-17-2011, 06:41 AM

I just had my new to me 951 aligned, with new tires and balancing done. Alignment shop does 911s and did all 3 adjustments with before and after on the 951.

At 70-80mph, I do get a very small, but perceptibly visible wheel shake (side to side). This is typical of a wheel that is not balanced. There are no wheel weights on the outside, I know for aethetics it is best to keep them on the inner lip.

These are cup1 17'' staggered wheels.

I brought the car back and asked them to check the fronts again, and to also correct the slight out of center position of the steering wheel. While the latter is correct now, I still have the wheel shake.

This shop also did my inspections/emissions, so they should have pointed out any deficiencies. I also just had rebuilt control arms put on, which looked and felt fantastic on pre-inspection.

Is the shop incompetent, or could there be something that is not known/difficult to find that could cause this? It really just feels like they did not do a good job balancing the wheels.

I usually try to find placed with Hunter Road Force balancing equipment, but I thought this place would be okay...

Thoughts welcome.

sparky4017 · sparky4017's Garage

I have never had any luck with stick on weights or all the weight on the inside i would have them rebalance and look for a bent wheel

krystar · 03-17-2011, 07:21 AM

maybe check your steering bushings or ball joint?

go back to the alignment shop and ask to see if they'll hook up to see if the alignment specs held. or if there's slack in the suspension that'd allow it to wobble

BryO · 03-17-2011, 08:07 AM

Had the same thing happening with mine. About 75 and up. Drove me nuts, so I replaced controls, tie robs and end, rebuilt rack, struts and string. Bearing in rear. Still the same thing.
Went over to a speed shop near the house, they do on the car wheel balance. Turns out my right rear rim was bent. No signs of anything hitting the wheel and looking at the rim you could not tell. But sure enough, replaced that rim and smooth now.

AKCJ · 03-17-2011, 08:59 AM

I had trouble last summer when I got a new set of wheels. Had to go back twice to get a good balance job. Each time the guy who did it said that the guy before him didn't do a very good job.

James Chimney · James Chimney's Garage

are the tires ok, I know they are new but they can have blemishes and be out of round.

ksudar · 03-17-2011, 01:35 PM

You need road force balancing. You probably have a wheel with a slight bend on the inside and it's not showing up on their machine. I just mounted a set of replica wheels with some minor bends on the inside of the wheel... did the RF balance and they're smooth at all speeds.

John_AZ · 03-17-2011, 01:48 PM

Similiar problem:
Spaced Out

GL
John

James Chimney · James Chimney's Garage

Quote:

Originally Posted by John_AZ

Similiar problem:
Spaced Out

GL
John

my mechanic says it is the front (used) tires "has a hop" and I have 2 new G-force Sport's coming will repost when I rode test.

jep32 · 09-23-2012, 03:32 AM

Same shimmy symptoms. Just had balance/alignment ..... same. What next?

John_AZ · 09-23-2012, 04:35 AM

What brand, size & name of tires are you using on the D90s?
John

jep32 · 09-23-2012, 05:29 AM

Std size Goodyear Eagle zr's

John_AZ · 09-23-2012, 10:18 AM

Very nice.
Have you tried this?
Spaced Out

John

alan6272 · alan6272's Garage

I have been fighting this very same thing. did all of the above, I am ging to get better new tires on my rear wheels then rotate them to the front and see what happens. Will also update but it may be some time till I do this, been very very busy and only drive my 944 once in a blue moon now.