[William Miller]

I drove to Annapolis and back twice in the last few days.

My stering wheel shakes intermittantly.
This problem has been there for a long time, but I'm rarely on the highway long enough for it to bother me.

I think it's my toe setting.
Why? The shake is only in the steering wheel and there is no vibration if you feel the dash.

The suspension is about as new as you can get.
Struts, bearings, turbo tie rods etc.

My camber is far from radical but I think I set the Toe to 0 deg or very close.

When I hit the flat concrete, the shake goes away. Sometimes on the asphalt it would shake and other times not.
This tells me that the cant in the road (allowing it to drain) or the slight hump in the center of the lane is what's partially to blame.

Maybe with so little toe the alignment changes ever so slightly ad the surface does.


Does any of this make sense?

I recall driving a go cart at the beach one time that had fairly big tires on it. the steering was so messed up that it would almost rip the wheel out of my hands.

I bet if I over inflate the tires that it might go away?

Any thoughts?

[LPM911]

have the tires rebalanced. when I drive at the track, the tire slips on rim and gets out of balance. when i throw the street wheels back on the steering wheel is fine.

[The Donkey]

Mine has a similar shake. I would be curious to hear some answers. 2 of my 3 911's have had this shake.

[roundel]

Have you replaced the steering column bushing? If not, the plastic one prolly is now dust. Pelican has a shim you hammer in without removing the column. They also have an article showing the repair.

DTBT

[William Miller]

Originally Posted by roundel

Have you replaced the steering column bushing? If not, the plastic one prolly is now dust. Pelican has a shim you hammer in without removing the column. They also have an article showing the repair.

DTBT

Just to clarify, this is not a vibration, but the steering wheel rotating back an forth quickly. The steering stays centered and there is no pull to one side or another on a flat road. It's like one tire is pulling it to the right and then the other one is pulling it back left, but it cancels itself out.

Would a slightly bent wheel / rim do this? There is no significant or easily visible dammage.

If all other things are equil, what happens if wheels are slightly toed out?
Slightly toed In? Arn't specs for most cars have it slightly toed in?

When I have a few minutes, I will try and adjust one tie rod a set amount, Like 1 revolution to toe it in a bit and see what happens.

The spec has a setting for wheels pressed in. I think this is because under braking the bushings flex and pull the fronts of the wheels out a bit?

[BlackTalon]

Sounds like toe, and/ or 'tram-lining' just due to the tires themselves (the grippier the tire, the more pronounced). Assuming the bushing are all okay, check the toe.

Toe-in is 'safe', and how auto manufacturers set up the cars. Toe-out has much quicker steering response (initial turn-in), which can make the car 'darty'. Good for track and auto-x, but the amount of toe-out should actually be pretty small. For pure street driving, a little toe in is probably best, or maybe zero toe.

[William Miller]

Originally Posted by BlackTalon

Sounds like toe, and/ or 'tram-lining' just due to the tires themselves (the grippier the tire, the more pronounced). Assuming the bushing are all okay, check the toe.

Toe-in is 'safe', and how auto manufacturers set up the cars. Toe-out has much quicker steering response (initial turn-in), which can make the car 'darty'. Good for track and auto-x, but the amount of toe-out should actually be pretty small. For pure street driving, a little toe in is probably best, or maybe zero toe.

Can you elaobrate on 'tram-lining'?

The current fronts are 7x16 BBS RS wheels with 225/50x16 tires. Dunlop 8000 and they have maybe 1/16 -1/8 tread left. They look like they are pretty evenly worn.
Radial balanced them for me last winter. But the issue was still there. Because I've done a lot of work on the front end there really isn't a lot of miles since then. Maybe 3,000-5,000 miles.

I was chasing down many problems so I refreshed most of the front end and even have new Bilstien Struts/spindles.

Can a wheel/tire be in balance vertically, but have a issue where it tries to move it side to side? At first, when this was happening, I thought the tire was slipping on the tire. I had that problem before on another car.

Yesterday, the problem came and went several times while driving 20-30 miles down rt 50. The changes were mostly when the road surface changed.

The shake is really annoying on a long drive. It will pretty much vibrate my whole arm.

[BlackTalon]

tram-lining is when the tires follow ruts/ imperfections in the road surface, yanking the steering wheel back and forth. It is exacerbated by the toe setting (much worse with toe-out).

Generally the grippier the tires, the more they are prone to tram-lining. And the more aggressive the front-end set-up (i.e., skewed towards track), the more it will tram-line.

[William Miller]

I'll try pulling the front's in (toe in) a bit at a time and see what happens.
I sort of think that is what's happening.
In most of the lanes there is a slight hump in the middle, I assume caused by big rigs with much wider trac.
In the right lanes it would have the hump and lean right for drainage.
Left lane hump and lean left for drainage.

On the concrete which I assume stay's much flatter, the shake goes away. Even though the surface would be canted for drainage, it was a pretty flat plane.

I also have the polybronze bushings and turbo tie rods, so more of the road is transmitted to the wheel.


I'll Report back later.
Thanks!

[FTS]

if toe-link bushing are worn, it will do the type of shaking you describe, but you mentioned that the whole suspesion is pretty new, so that's probably not the cause.