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.

 

Had a little excursion to Minnasota last year and thought I lost a wheel weight, ya, only a 60-70 mph shimmy. Was on brand new asphalt, pavers still on the side of the road. Crossed the State Line into Fargo N.D.... problem solved.

 

So could be I am just being too sensitive?

 

Were did you buy the tires? They could be out-of-round. Can happen.

You should have them road forced balanced. Tire Rack can assist you with locations that have this equipment.

 

Yup, a speed-specific shake is usually a balancing issue.

Does it go away, once you get passed a certain speed?

Are the wheels OEM, or reproductions? If the latter, I've seen many cases where the fit on the hub is off just enough to cause a shake, and balancing wont fix it.

Could be bearings, but I'm guessing not...

 

OEM wheels, offset is different but lots of people run 17'' cup 1 or cup 2 wheels.

Tires are new from Tire-rack. Shake 'was' 60-80mph', after having them look at it again, now it's more like 70mph-80mph. Have not shot past 80mph to test, I may.

 

No, just saying that it could be the road construction, as every mile of road in Minnasota seemed to have that same 'Low Standards' problem. Could also be a tire construction issue, or resonant mechanical condition ... Motor mount, balance shaft, axle, ect.

 

Motor mounts are new-ish.

It's just the steering wheel, not the car.

 

doubt it would be the wheel bearings. If it was, you will feel a slight grinding feel on the floor. It's not smooth at all.

This much be a stupid question but are all the wheel nuts the same?

 

Wheel bearings are good.

No, they're not all the same. I think 4 are the standard and 1 is the 'lock nut' one without the key portion installed (thanks PO). Could that be it?? Condition exists on both front wheels...

 

Good point Paulyy, I've heard of this problem long ago, and it's second nature now, but have you loosened the lug nuts and retorqued them to spec? Rattle guns can easily over or under tighten the wheels causing issues, 96 ftlbs in a criss-cross pattern is the stock recomendation.

 

This place said they do 96 ftlbs by hand, no torque sticks. [I mean, doesn't mean they do it, but they said beware of quick change places over torquing with sticks]

 

What does this mean? Did they use a torque wrench or not? You can't guess by hand.

 

They told me they did when selling me the service (I was going to get wheels and tires mounted and balanced elsewhere).

 

Any chance you are running spacers? I have had shimmy with spacers before.