New tires or front end allignment issue
 

Had this 83 911 widebody for about 2 years and recently noticed the steering wheel shaking left to right up to a half an inch sometimes. At freeway speeds around 60. Went to Les Shwab today to check the balancing but they were only off .5 ounce and the issue is still there. Only shakes sometimes on the freeway when the tires are "out of sync"? It can be smooth driving untill a small turn. Then the shaking begins and will go away again if the turn is long enough. Seems like some sort of balancing issue or flat spot when the outside tire is not matching the inside tire. The shaking will continue in a straight section if the shaking was happening as I exited the curve. There is some mirror cupping on the outside of the passenger tire and inside of the driver tire but likely due to tracking the car and the tires are only A traction tires while the backs are AA traction so it pushes on the track. Tires are 235 40 18's and zexius brand.
I havent done a wheel alignment but it tracks straight on a flat road. By the way Les Schwab didn't do a load test balance, just a regular spin. Wouldn't an allignment issue happen all the time and not just sometimes?

Have them check the front wheel bearings.

Or you can. grab the tire inside the wheel well with both hand and pull back and forth.

For a proper check raise and hold at 2 & 7 and check for movement. If loose tighten

Next would be to check the struts mine were loose and had to be tightened down.

Check tire pressures first if you haven't already. Not sure about the brand of tire you have, but look at the weights. If you see large weight on one tire and very small weights on others, they're either very inconsistently worn and or very inconsistently manufactured. Though it's not the same vehicle, had the same problem on my Cherokee and an alignment and rotation balance took care of it. I only noticed the vibration at highway speeds between 45-65.

I lived in Washington state for several years. I have had bad experiences with several Les Schwab dealers.

But then again, I'd be checking for loose wheel bearings like Jim (Draco) recommended. If it's not the bearings, I'd be concerned about the tires and the balancing.

You said it is a wide body. Any chance it has bolt on wheel spacers that may have come loose?

jacked up both front tires and checked the 9 to 3 and 12 and 6 positions for any bad bearing movement. I would have to say no. I have replaced hub bearings before in a trailer which were making the rim visibly wobbly. This is no where close.
Im guessing tire, or allignment issue is the only solution.

Ditto! Spent $875 for tires on the wife's van. Went to Seattle and it was shaking so bad that I thought one of the tires was coming off. Took it back and they balanced the tires which they said they don't normally do upon initial install. (REALLY?!) Drove it to Seattle again and the same thing happened. Turns out one of the tires was defective and had to be replaced.

Needless to say...Never again!!

Go to a Rim repair shiop and have them check the balance and the rims itself. It may need to be straightened out.

My rim was bent and the Custom Wheel Shop could not balance it properly. Just tires said they balanced it but impossible.

After the rim shop fixed it, it did not even need weights :)

The Toyos on my f150 shook that I bought from them, too. Rotating and balancing them every 5000 mi. helped a bit, but they always shook some.

Put Bridgestones on this fall and the truck rides as smooth as a Cadilac.

if your car has set for a long time you may have flat spots, pretty much not gonna come out,

I suggest you take it some where and ask if the can spin the wheel on the balancer you then can see what the movement is, sometimes just rotating the tire on the wheel will work, but if it is running smooth then they are peobably using a old balancer that only will do static, see if you can find someone with a hunter rolling balancer, Kevin

I have always suspected flat spots but the tech said you can't flat spot a radial tire. The car sat a bit when i bought it and it does set sometimes up to a month.

Here's a GM service bulletin I found on a Monte Carlo forum but tires are tires.

Here is a GM Technical Bulletin with some interesting tire info on this very topic.............

[hr]

[align=left]



Subject:
Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires #03-03-10-007C - (09/21/2007)[/align]
[align=left]



Models:
2008 and Prior Cars and Light Duty Trucks (Including Saturn)[/align][align=left]




2008 and Prior HUMMER H2, H3[/align][align=left]




2005-2008 Saab 9-7X[/align]

[hr]

This bulletin is being revised to include additional information and model years. Please discard Corporate Bulletin Number03-03-10-007B (Section 03 - Suspension).
[hr]

The purpose of this bulletin is to help explain that , under certain circumstances, a customer may notice a slight tire shake within the first few miles/kilometers of vehicle operation.
Tires may be designed with a nylon overlay configuration engineered to enhance the tire's integrity at high speeds. This allows the tires to be driven at higher speeds without excessive heat buildup.
Important:Before measuring tires on equipment such as the Hunter GSP 9700, the vehicle MUST be driven a minimum of 16km (10mi) to ensure removal of any flat spotting. (The tendency to "flat spot" is less likely as the tire accumulates mileage.)
When parked overnight, or for a period of time, the tires may set (flat spot) and require a few miles/kilometers before heating up to their normal operating temperature. Until the tires warm up, a slight tire shake may be felt but should subside quickly.
Important:DEALERS SHOULD REFRAIN FROM ATTEMPTING REPAIRS OR REPLACING COMPONENTS.




GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.


WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
© Copyright General Motors Corporation. All Rights Reserved.
[hr]

there are 2 kinds of flat spots. one is where the tire sits for awhile and flattens out a little at the bottom. the other is where you lock up the brakes and scrape off lots of rubber on one spot. if the latter happens I'm not sure there is any way to get rid of the shakes.

You need a new tech.. Any tire with nylon in it is subject to flat spotting.. This usually goes away as the tire warms up, as referenced in the above GM TSB.. Also as referenced above, wheel balancers are not created equally.. Find a tire service that can do a tire/rim match and a dynamic balance.. At the college I had the latest Snap-on/ John Bean balancer and it did the best job of any I tested.. Hunter Road Force is a close second.. Of course you always have to factor in operator experience~error~ also.. IMO, .5 out IS an out of balance tire.. Then again you could just have a bad set of tires, I'm not familiar with that branding..

BTW, is "Les Shwab" a chain?? I'm not familiar with them, since I live on the East coast.. It's been my experience 'chains' are ok for grocery getters, but not perfomance cars.. Again, my $.02..

not sure where in WA state you are but if you're in the seattle area, Tru-line is a great place for wheel issues. i used them for my alignment, corner balance and tire change and love the results. they have a bellevue and seattle location.