Evil steering shake at 65mph+, not sure what is the culprit

[TSI]

Having taken my car out of storage, I noticed that I have a real nasty shake in the steering wheel at highway speeds (anything 65mph+). Nothing below that speed, and the shake is odd: some days it won't be there, some days it will. Turning sometimes makes it worse, sometimes better. Braking does not affect it.

In the last 1000 miles:
New front tires
2x alignment and balancing
New Lemfoerder tie rod ends
New front pads, rotors and calipers

The vibration is sometimes transmitted into the seat, sometimes not. Nothing out of the ordinary from the tranny tunnel either. Clutching in makes no difference.

Not too sure what might be causing this. I've been told the wheels could be bent (but they balance fine), could be the sway bar, could be hubs.
Any ideas?

[jlevie]

Vibration that you feel in the steering wheel comes from the front suspension and if from the seat the rear suspension. Vibrations at speed can be from worn suspension parts, worn shocks, bent wheels, out of round or out of balance tires, or flat spotting of tires during parking. If the vibration isn't always present, bent wheels can probably be eliminated as a cause. And bent wheels would be obvious when balancing the tires.

[TSI]

Vibration that you feel in the steering wheel comes from the front suspension and if from the seat the rear suspension. Vibrations at speed can be from worn suspension parts, worn shocks, bent wheels, out of round or out of balance tires, or flat spotting of tires during parking. If the vibration isn't always present, bent wheels can probably be eliminated as a cause. And bent wheels would be obvious when balancing the tires.

That's exactly the issue. I looked at them on the balancing machine, and they appeared fine, a point corroborated by the fact that the vibration is intermittent. I'm 90% sure it's something in the front suspension, but again, the intermittence means I really don't know where to look. Shocks could be the issue, but then why only above certain speeds? It's a night and day transition once I hit 65.

[Cabriolet]

are you running the stock rims? or something aftermarket that may not be hubcentric?

[TSI]

are you running the stock rims? or something aftermarket that may not be hubcentric?

I am running Rial RS6s with hubcentric spacers. I just put on a set of winters I have, we'll see in the morning when I go back on the highway. Just checked everything while I was under, nothing is loose (one sway bar bushing is a bit tired)

[TSI]

Took the car out for a spin withe the winters. Still have a shake, although not as bad. It is definitely more pronounced under braking.


One other thing: the rears were noticeably unbalanced. I'm thinking the fronts could be unbalanced as well, which might mess up my test.

[jlevie]

A noticeable shake under braking is probably from worn parts in the suspension. My approach would be to replace the control arms, inner tie rods, control arm bushings, struts/shocks and mounts, rear trailing arm bushings and subframe bushings and to check the wheel bearings for wear and replace as indicated.

[Roysneon]

I've got the same thing going on, but I'm assuming it's the old, bald tires on the car or the small spacers I put on the front. I'll remove the spacers this week and report back, will have new tires next week and will do the same.

[Roysneon]

I took the wheel spacers off and my car is now solid as a rock up to at least 140kmh.

[mr2peak]

That's why hub centric spacers are always recommended

[TSI]

That's why hub centric spacers are always recommended

That's what I have. The wheels have high offset, they won't fit without the spacers unfortunately. Which brings me on to an update: I went back to the 16"s after my test above, and the shake is now much less pronounced at 65--it seems the heavy shake has been pushed up to about 70-75. I rechecked all the suspension components, everything is good and tight. One strange thing though, when I turn at high speed the shake appears to extend to the seat.

Hubs or bearings perhaps?

[Roysneon]

If there is play in the front suspension top and bottom, likely a ball joint, if front and back, likely a tie rod. If both likely the bearing.

Grab the wheel at the very top and very bottom and rock back and forth, the do the same with the front and back of the wheel.

[Eric]

worn control arm bushings.

[TSI]

If there is play in the front suspension top and bottom, likely a ball joint, if front and back, likely a tie rod. If both likely the bearing.

Grab the wheel at the very top and very bottom and rock back and forth, the do the same with the front and back of the wheel.

Did that. The only play I get is in the shock/spring movement. Everything else is tight. I suspected the spacers as well, but the car had a similar shake with regular bottlecaps.

worn control arm bushings.

See above. They have 5000 miles, all tight.

[jlevie]

With the changes in behavior as you play with the wheels and spacers, I have to say that the car needs a full suspension rebuild. If you have a worn suspension, that wear will aggravate the slightest error in the wheels/tires. So a little error in a spacer or hubcentric wheel with trigger the vibration.