Tracking the BX

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Tracking the BX

Post by tomsheppard » 27 Sep 2004, 19:06

Driving David's BX, Graculus, I realised that my own car didn't steer well for a BX. Track rod ends were due anyway but how to track the brute. You can't get wetter than a thick drip fitter so DIY had to be the option. First do the research.
The total toe out between 0 and 3mm.
Car is crab tracked by 56mm. (Estate)
Wheelbase is 2655mm.
Rim diameter is 365.6mm
Two laser spirit levels, were bought each costing a massive £4 (saw a bargain and thought I'll invent a tracking gauge)
once magnets were added to the smooth ground bases of the lasers, they fitted onto the wheels and the
beam came out parallel to the wheel and the level could be adjusted.
a 300 mm rule was cut in half and a magnet attached to the end to sit in the rim of each rear wheel. The edge of the rim was 45mm from the edge,the offset was a further 28mm, (Half the track difference,) and the laser beam is 27mm from the rim edge. Total offset was 100mm
So if the laser beam hits the ruler at 100mm then the wheels are set parallel and if they are the same both sides then it won't run after the camber like most BXs do these days.
And if you do a bit of maths, divide wheelbase by wheel diameter and multiply by half the totoal toe out, you end up with 11 which means
89 mm is the maximum toe out.
Car is set up on level ground, handbrake off and engine running
fuel warning light on and empty. Suspension on normal. You'll need a 19mm and a 13mm open ended.
So after all this effort, Did it work?
[:)]You betcha!

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Post by paranoid » 27 Sep 2004, 19:26

I go to my local fitter, who's excellent (you may have seen him on telly, the only tyre repairer who could fix a puncture to trading standards errr standard.) After he did mine with all the lazer gear it felt like a racing car. With all the speedbumps around he reckons tracking needs doing at least every 3-4 months (and no he wasn't trying for business he's a mate) Cits seem paticularly bad for going out of skew doesn't know why though.

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Post by bxbodger » 27 Sep 2004, 19:31

I think you have been very lucky indeed!!!
Most of those cheapo DIY laser levels have beams which are so diffused, weak,fuzzy and wobbly that no builder will entertain them!
I did once try to build a tracking gauge on the telescopic pointer principal but it was just too coarse to be any use.
I ended up buying a track-rite, which seems to be more accurate than it has any business to be.

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Post by tomsheppard » 27 Sep 2004, 19:55

I used the system in the evening for just the reasons stated! The beams don't wobble over any measurement that would have any effect on the reading.

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Post by uhn113x » 27 Sep 2004, 21:59

Sounds good, Tom. Any chance of pics? A while ago I called on my friendly MOT man and spent an hour with a vernier and tape measure making drawings of his laser tracking gauge, which just works on the same principal as the optical ones - a mirror on one side and a laser and scale on the other.
Put it in the 'I'll make one when I get a round tuit' pile.
I believe the better ones put the lasers on the rear wheels and the scales on the front ones - not been able to find any more out.
Cannot use a TrakRite as not enough level driveway! [:(]