Steering wheel shake....

[That986]

Hope you guys can help me here or confirm my thoughts,..

A few weeks ago my car went in to be wrapped and at the same time i had the wheels refurbed and new tyres put on. I plumped to get Avon ZZ5 tyres after reading some good things about them and also having good results myself with Avon in the past.

A couple of days after getting the car back i went on the first cruise out with the better half next to me and when we got up to motorway speeds the car started to vibrate through the steering wheel. I put this down the balancing being out on the wheels somewhere and while we were out i checked all the pressures were fine, they were after a small adjustment but the vibration was still there.

So this weekend I popped into my local tyre guys who I know really well and got them to balance the wheels from scratch so i knew they would all be spot on again. Wheels balanced and off i went, got up to 70 mph and there it is, shaking again....

So now I'm a bit mystified to what's going on. The car was gone through and hunter aligned at the beginning of September and hasn't really been driven that much since. The car felt rock solid before it went in on fairly worn Michelin so the only variable that has changed is the refurb and tyres.

I'm leaning toward one of the tyres being bad as when they were balanced again on Saturday there was one wheel took 90g and more to balance out.



What do you guys think?

[BoxsterSteve]

Wow... 90g to balance?
I'd start with having the shop replace that tire. If that doesn't fix you up, then it's the wheel itself. Have them put the suspect wheel on the balancing machine without a tire on and spin it and see what happens.

[That986]

Originally Posted by BoxsterSteve

Wow... 90g to balance?
I'd start with having the shop replace that tire. If that doesn't fix you up, then it's the wheel itself. Have them put the suspect wheel on the balancing machine without a tire on and spin it and see what happens.

That was my thoughts, sounded way too much. I know the wheels are good as before the refurb everything was rock solid. The 2 variable that has changed are the wheels have been painted and the tyres changed.

[JayG]

See if you can find a shop that has a RoadForce balancer

They are much better with a problem tire or wheel

Have you tried a different set of wheels or even swap front and rear for a test drive and see if you have the same problem

[PaulE]

My 2003 S is very sensitive to tires and wheel balance. I've owned it since new and it always has been. I tried a set of Toyo Proxes Sport tires and couldn't get the car to stop shaking at 70ish speeds. This was on OEM 17 inch wheels with the OEM tire sizes. My independent Porsche garage checked everything out and narrowed it down to 1 front tire which was replaced under warranty. That still didn't help. After 8,000 miles those tires still looked like new, but I threw them away and went back to Michelin PS2's which are much better. My independent garage said they didn't have good luck with Toyo tires on Boxsters and that they were very sensitive to tires. Good luck with finding a solution, I know how frustrating it can be to have your steering wheel vibrating and annoying you.

[That986]

Well it turns out that one of the mechanics who did the alignment 6 weeks ago is blind as he couldn't spot a failing tie rod. The wheel grab checked confirms it, rocks about (a lot now after ramming it over a couple of sharp speed bumps) when you grab at 9&3.
I'd ruled this out as the car had been gone through mechanically at the beginning of September with the instruction to replace anything that looked worn or tired, obviously this was never looked at.

I'm super annoyed with these guys as i was about to start looking at other wheels and running round to see if i could get more tyres tried out when it is exactly what i thought it normally is when you feel that kind of shake.

Anyway, the car is now booked in at the local garage to have all the inner and outer rods replaced (if one has gone, the other is never far behind) and then align it again.

Thanks for the advice guys.

[jayspeed999]

Originally Posted by That986

Well it turns out that one of the mechanics who did the alignment 6 weeks ago is blind as he couldn't spot a failing tie rod. The wheel grab checked confirms it, rocks about (a lot now after ramming it over a couple of sharp speed bumps) when you grab at 9&3.
I'd ruled this out as the car had been gone through mechanically at the beginning of September with the instruction to replace anything that looked worn or tired, obviously this was never looked at.

I'm super annoyed with these guys as i was about to start looking at other wheels and running round to see if i could get more tyres tried out when it is exactly what i thought it normally is when you feel that kind of shake.

Anyway, the car is now booked in at the local garage to have all the inner and outer rods replaced (if one has gone, the other is never far behind) and then align it again.

Thanks for the advice guys.

Was this problem ever solved? I just picked up a 2001 "S" and experienced the same thing. It does not happen every time I go over 75 mph. However, this is the same situation that occurred with one of my prior cars, a BMW 740 Xi. I learned what caused the vibration with that car: Cold, slightly squared tires.

Specifically, when I would park in my office's parking garage and leave it there for 8 hours or so, the tires would cool down a lot as it was colder in the garage than outside. Most of my drive home (around 17 minutes), I would experience the vibration.

However, if I parked outside my house in my driveway, then drive the car, there was no vibration at all above 75 MPH. I experienced the identical thing today with my Boxster: Yesterday after parking in the parking garage, I had vibration. But this morning, after sitting in my driveway with sun, there was no vibration detected above 75 MPH.

YMMV, but this has now been consistent and I think that in my case, this is the cause of the vibration. I believe that when the tires get cold, they retain the slightly flat or "square" shape where the tires contact the cold concrete. I believe the "squared" tire is the cause of the vibration. That is why the vibration does not occur when sitting in my driveway in the sun: the tires do not get cold enough to "square."

[BYprodriver]

Originally Posted by jayspeed999

Was this problem ever solved? I just picked up a 2001 "S" and experienced the same thing. It does not happen every time I go over 75 mph. However, this is the same situation that occurred with one of my prior cars, a BMW 740 Xi. I learned what caused the vibration with that car: Cold, slightly squared tires.

Specifically, when I would park in my office's parking garage and leave it there for 8 hours or so, the tires would cool down a lot as it was colder in the garage than outside. Most of my drive home (around 17 minutes), I would experience the vibration.

However, if I parked outside my house in my driveway, then drive the car, there was no vibration at all above 75 MPH. I experienced the identical thing today with my Boxster: Yesterday after parking in the parking garage, I had vibration. But this morning, after sitting in my driveway with sun, there was no vibration detected above 75 MPH.

YMMV, but this has now been consistent and I think that in my case, this is the cause of the vibration. I believe that when the tires get cold, they retain the slightly flat or "square" shape where the tires contact the cold concrete. I believe the "squared" tire is the cause of the vibration. That is why the vibration does not occur when sitting in my driveway in the sun: the tires do not get cold enough to "square."

Thanks for searching ! Sounds like you are on to the problem. Most ultra-high performance tire can "flatspot" when cold as you have discovered. If the tire uses nylon for tread belts it is more likely since nylon expands & contracts greatly with temperature extremes. Read your sidewalls it should list tire construction materials for tread & sidewalls.

[jayspeed999]

Yup - I checked the tire composition on the sidewall and it is polyester. I have the Contentinals. I'm assuming polyester is nylon.

[Lapister]

Ditto on flats spots as my Hankook Ventus EVO 2 do this for about 15 min after being parked overnight. Once warmed up they are sharp and smooth!