Castor/Steering problem

[stainesy]

Camber though, not castor.

yep, they have 3 bolts to line up and you have movement in all 4 directions (more inward/outward for camber) but there is also for/aft movement too

You have 1-2mm...not enough in all honesty.

i disagree. even a few mm in one place can put things out alot more somewhere els.

i was messing around with my camber on the front a few weeks ago and it only took a couple of mm movement on the bolts to move the tyre quite alot in or out of the arch by cm,s.
so maybe that could be doing the same kind of thing.

[Stirring Moose]

From the symptoms described sounds like either something is severely bent or something is sticking on one lock. What does the car drive like? I would have thought if the caster was sufficiently out of whack to lose all self centering in one direction the car would be all over the place in normal driving, constantly trying to explore the other side of the road. If the car drives normally, except when on full lock as you describe, I would be more suspicious of something sticking in the steering system.

If you want to check if you're casters are equal, you can get an idea by measuring the camber change with lock. You'll need to lash up some kind of straight edge/spirit level contrivance to measure camber and you'll need the car on a good level floor. Measure camber with the wheels straight ahead then wind in a precise amount of lock e.g. 360 steering wheel degrees. Measure camber on the inside wheel and note the change. Repeat with equal but opposite lock and measure camber on other wheel, again noting the change from that registered in the straight ahead position. If the camber changes are about equal then so are you're casters.

If there is a caster imbalance and it's only minor, it can be dialled out with set up. My 'Valver had this problem and as a result had a very slight pull to the left. The guys who I take the car to when I run out of time and/or talent used up such caster adjustment as there is and then tweaked out the last bit of pull with a slightly assymmetric camber set up. Now as has already been pointed out, KwikFit don't really get into that type of thing so it might be better if you took your car to someone who really knows what's what with suspension set ups.

S.M.

[Ess_Three]

i disagree. even a few mm in one place can put things out alot more somewhere els.

i was messing around with my camber on the front a few weeks ago and it only took a couple of mm movement on the bolts to move the tyre quite alot in or out of the arch by cm,s.
so maybe that could be doing the same kind of thing.

You can disagree all you like...but a Mk3 balljoint has NO caster adjustment on it...it has fitting tolerances that are 1-2mm, the difference of which falls within the acceptable castor tolerance on the alignment.

Mk3s use the two strut bolts as camber adjustment..what you can get on the balljoint doesn't even come close to what you can get on the strut.
you can get maybe 6 or 7 degrees of cambwer adjustment on the front.

There is NO castor adjustment...for it to be out of tolerance wildly something has to be bent.

Even if you add up movement on the subframe bolts and movement on the balljoints, you are looking at fractions of a degree - 0.2-0.4 degrees...which I doubt is enough to fix this problem.
On the Mk4/TT/S3 (that had NO camber adjustment) moving the balljoint 10mm gave approx 0.2-0.3 of a degree of additional negative camber...
so what will 1-2mm give?

But, as you say, a few mms here and there has the affect of throwing the lot out...

[deeman]

Thanks for your replies!
The machine kwikfit used is some new fangled computer thing that measures all 4 wheels.
Don't really know the accuracy but the result it came up, castor out.. This would cause the steering problem.
Think I will start with replacing that lower arm and then go from there.
And yes, will find a specialist garage next time.
Thanks again!!

[tshirt2k]

I'd go to a proper alignment place an get some accurate readings and a printout. I have slightly less castor on my left front which i think causes a slight pull to the left. All wishbones were new so all that it can be is my subframe, which means its slightly set back on the left wheel.

[Stirring Moose]

Shortage of left camber would cause pull to left as less camber equals less camber thrust. Camber is adjustable on a Mk.3 though so you should be able to dial this out.

S.M.