My '96 STI has a steering vibration which only occurs at or around 70mph - at 60 or 80 it's dead smooth.

I've had the wheels balanced and haven't owned the car long, can anyone please suggest what the problem might be?

Ta
Andy.

 

tracking or geometry

 

On another car I had a bad tyre (from new).
Had it balanced and checked tyre pressure and tracking loads of times. In the end new tyres on the front fixed it.
Hopefully it'll be something less expensive for you!

 

I'd get the wheels balanced again, I've had this a few times after buying tyres. Sometimes they only spin the wheels once, add the weight/s and that's it, rather than keep spinning it and adding weights till it reads 0. Even 5 grams out can make your wheels judder.

 

Mine was doing this and got progressively worse.. Turned out power steering fluid was low

 

When they balance the wheels check the sidewalls for bulges as they spin...

Does it go away if you brake very very lightly?

Simon

 

try doing a front to rear wheel swap this should tell you if its a balancing problem or not.

 

Swapped the suspension today (to replace a worn-out damper) and tried a different set of wheels & tyres - neither made any difference, except that it was a lot worse just for a few seconds the first time I hit 70. By the end of a brief test drive it was back exactly as before.

So, not wheels or tyres, then. Power steering fluid level is fine, though I have heard some unpleasant squeaks coming from the area of the power steering pump itself.

I think the next job is to check the run-out in case, maybe, a hub is damaged, and then maybe replace the power steering pump - unless anyone has any better ideas?

 

have you had the tracking/geometry checked?

 

No - though having just changed the suspension, it'll need doing anyway.

Why would that cause vibration though?