Simon
Firstly the accuracy of a tape measure or whatever isn't really an issue as all you are looking for is the difference - not the absolute measurement - so in fact all you need is a conveniently located scale.
Secondly toe in/out is quite easy to measure and adjust when its nearly right. The idea of looking at the back wheels is simply to arrive at a starting point which is nearly right and from which the final adjustment can be made. If the rack is substantially off centre you are likely to start adjusting the tracking with the wheels nearly parallel and pointing quite determinedly to one side. Its far easier to get them straight before you start.
If you suspect the rack on your father's car is misplaced following its accident - then why not see if its position can be measured from fixed points - for example cross members and other points. If any dscrepance is found then it can be investigated.
wheel alignment/tracking
Moderator: RichardW
Be wary of trying to line the fronts up on the backs visually- I don't know about the Xantia, but the BX front and rear tracks are different, I think its about an inch narrower at the back.
I have seen people recommend you line up between two front to rear scaffold boards, but you also need to take into account the difference in track width.
Me, I use a gunsons trackrite after any suspension work- it takes about 5 minutes to get spot on alignment. I bought it after getting fed up with idiot tyre fitters who only ever adjusted one side. The things paid for itself many times over in the ten years or so that I've had it.
Incidentally, with regard to rack centering, British Leyland, for all their faults, used to provide a hole in the centre of the rack through which you dropped a bent nail or similar which locked the rack dead centre, allowing you to make the adjustments from a known starting point.
I have seen people recommend you line up between two front to rear scaffold boards, but you also need to take into account the difference in track width.
Me, I use a gunsons trackrite after any suspension work- it takes about 5 minutes to get spot on alignment. I bought it after getting fed up with idiot tyre fitters who only ever adjusted one side. The things paid for itself many times over in the ten years or so that I've had it.
Incidentally, with regard to rack centering, British Leyland, for all their faults, used to provide a hole in the centre of the rack through which you dropped a bent nail or similar which locked the rack dead centre, allowing you to make the adjustments from a known starting point.
TIP
oh, i had a tip off my cousin.... Demon Tweeks in Wrexham do computerized readings, very detailed too, he got me his report out, they said something needs to be checked before they adjust his car, so seems like a decent service too... £36 is what he says they charge.
i'll bare that in mind jeremy, thanks! so if the rack is in the middle, and the tracking is right after some adjustment and ur steering wheel still isn't in the middle u can bet it's the steering wheel not in the middle, not sure how they are on a citroen xantia, but some cars have splines to fit the steering wheel, others fit only in one position.
That's right - get the rack centralised and work from there. The wheel fits on fine splines - least it does on BX and ZX. The wheel has to be removed for a number of jobs like replacing panel light bulbs and most mechanics will put it back on straight - so they can easily get set in the wrong relationship to the rack.
jeremy
jeremy
jeremy