Porsche Enthusiasts Club Forum

Hi All,
For weeks now I have been trying to eliminate front wheel wobble/vibration from my late 85 oval-dash 944. It is fitted with Avon ZV3s, and displays at times alarming shaking at the steering wheel, at speeds varying from 60mph up to nearly 90mph. The problem is not consistent, though, on occasion being virtually non-existent, but then a few miles down the road returning with a vengeance.

The rims are Fuchs alloys, 7x16, fitted with 205/55 16s, pressures 2 bar ( 29psi ). They have been balanced 3 times in all, once by fitting to the balance machine with studs/nuts, rather than using the centre hole. All alignments etc have been double-checked, and none of the wishbone bushes look shot. It has no play in joints or wheel bearings. On smooth acceleration up through the gears, no vibration occurs - it is only when cruising at a constant speed.

It is the erratic nature of the problem that is so puzzling to me. Does this sound familiar to anyone out there and, if so, what is the solution please ?? All/any help gratefully received, people ! Cheers.

Squibby ( TIPEC member )

Hi

I would say wheel bearing from experience with my 944, but you say you've already checked that so perhaps you have a wheel that is out-of-round?

Adam

possible sticky brake caliper which will grab the disk and cause it to heat up and warp slightly, this sounds like a very good candidate due to its intermittantness.

That would probably cause erratic braking too, which might be a giveaway. These cars are also very sensitive to geo setup which I suspect can cause some vibration over rough surfaces (like our beloved M20 par example )

sounds like a worn wishbone rubber to me

I have just had a similar issue, although not so severe, with my 968. It turned out to be old tyres that had gone out of round from standing for too much of the time

How old are the tyres on your car?
There should be a 4 digit date code somewhere on the sidewall.

? Do you mean the balljoint, or the rubber bushing where it joins the body ?

Could be either, but it would be unusual to be intermittant & also not seen this happen at variable speeds. My bet would be a tyre. Can you borrow a pair of fronts wheels just to try? The other thing is what are the steering UJ's & rack like? A knackered kick pad in the rack could do something like this.

Not only old tyres - I had a new one that was less than round!

It was amusing to see the poor kid trying to balance it as it wobbled around on the machine.....

Thanks for all replies to date, guys. Much appreciated.

We have tried a different pair / make of tyres on the front - made no difference. My tyres are pretty new, say 1000 miles in.

Will run various checks in light of all your kind offerings and maybe one will be the solution !

Squibby

I had a similar issue with my old Lux. It my case it was the steering uj tie bar.(i think that's what its called) the part that passes the exhaust manifold. On the early cars they didn't have a heat shield and the joints would simply burn all the grease out and ware out.

potentially both

Hi

Did the steering feel heavy too?

Adam

Oh god yes it was heavy as hell. But it didnt have power steering so i just put it down to that.


Stu

Further to this thread, my car has alloy lower wishbones. I am told by my local OPC and by the Haynes manual that at least one, if not both, of the bushes in these cannot be replaced and I will need the complete units. Is this true, or are Porsche just getting people to spend out, and Haynes simply following the ' party line ', as it were ?

Also, assuming the bushes can be changed, any comments on standard rubber ones against polybushes ?

Thanks again.

Squibby