Post
by blm70 » Wed Feb 24, 2016 7:15 pm
sulli wrote:Have a wheel wobble at above speed, vibrating steering wheel, ok under 45 and over 65 really.
So is it likely wheel balance, tracking, suspension bits or what? Could do with a steer (see what I did there

) before I go off getting costly diagnosis.
Ta

In my experience of wheel vibration, the causes can be myriad. Balancing is almost always the first suggestion but doesn't always help.
Whilst suspension components can be culpable, this can be very hit and miss and you may well end up replacing lots of expensive parts to no avail (got the t-shirt..)
I'm assuming your alloys are standard as even non-standard wheels can cause vibration?
My advice would be to:
a.) as said above - swap front to back (cheap & easy);
b.) check balancing, ensuring the operator is competent (I always watch/talk to them);
c.) remount the tyres as they can suffer from flat spots - even on new tyres - the wheels will also need to be rebalanced;
d.) check the wheels are actually round and get them straightened if necessary - the effects of a slightly out of true wheel will be greatly magnified at speed.
I had a very slight (almost negligible) vibration between 55 and 65 that came and went after having brand new tyres fitted last year. Tried swapping front to back and balancing at a few different places - once with a Hunter balancer - but it was still there.
My wheels were recently refurbished and they found that three required cosmetic welding around the bolt holes plus one needed straightening. In addition, one of the tyres had a flat spot so it had to be remounted/balanced out.
Once all this was done - no vibration
PS - I was also advised that inflating the tyres to say 60psi, then dropping the pressure to normal levels could encourage out of round tyres to return to their original shape. Tyres that are stacked upright, rather than flat are at risk of deformation.
Current:
TT Mk1, 225 Quattro Misano Red, AmD map
Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.