Tyre wear and tracking

Theo Markettos gurgled happily, sounding much like they were saying:

Tracking doesn't just "drift". It can only go out of adjustment by being knocked.

Equally, it can't be out on just one side. If it was, you'd go round in circles - to go straight, you "average out" any tracking inequalities, which is what causes the wheel to be off straight. Anything that's just on one wheel is down to other positional inaccuracies of the wheel - a bent arm, collision damage etc.

You really need to get the car properly inspected by somebody who can align it all properly - castor, camber and toe. It'll cost a bit more than just toe, but it'll show more.

Severely shot bushes could well cause that much movement, but there's no way that the car'd pass an MOT like that.

I've had what the OP had when I once was stupid enough to let Kwik-Fit track a car for me. Within 200 miles, less than a week, it had worn the insides of the tyres down to canvas. Seemed OK to drive and steering was dead ahead when you took your hand off the wheel.

Took it elsewhere. It was way out and they'd only tracked it on one side as well as the trackrod end was seized and needed heat to free it on one side. It also turned less to one side than the other.

First port of call would be to get a free tracking check at somewhere else.

Sounds like you're having the tracking checked by people who use those new-fangled 4 wheel computer alignment thingies which IMO are crap. Well they're not crap but they're operated by monkeys who don't understand them and just twiddle the track rod ends as the system tells them to even if the system is faulty or they've entered the wrong car details. I had a mate get his tracking done by one of those on a Peugeot 205 and he phoned me to say it was dangerous to drive, unstable at speed and trying to slide off the road at every corner. He brought it round and the tracking was over half an inch out. You could easily see by eye the wheels pointing out at the front from the wheelarches on both sides. Supposedly it had been set to parallel. It had started to wreck the tyres already on the single 300 mile journey he'd done since having the tracking set.

Phone round until you find yourself an old time garage with a bloke who has an original Dunlop tracking gauge. You can't fool one of those and they give perfect results every time.

Sounds like you could do a better DIY tracking job than the places you've been to. There's plenty of guides around on how to do it. Here's a few, none of which I've tried, I have my own method which may only work on my car, but just using a tape measure between the 2 front tyres on the front and back edges can get you close.

You should always be able to get the steering wheel to be straight. Some cars will try to follow the camber of the road a little, but the steering should be straight.

Wear will alter geometry slightly. Geometry (tracking - toe in or out, camber - angle of the wheel face compared to the vertical, castor - angle of the suspension strut etc.) should not spontaneously alter. Camber also affects tyre wear, and castor adds camber with steering lock and provides steering self centring.

My advice to you would be for you to take the car to a bodyshop or motorsports place who have the gear and know how to set the car up properly. Not just the toe (tracking) but also the camber and castor. Camber and castor are unlikely to be adjustable on your car, but at least you will know why the car is wearing tyres like it is.

TBH it's a Japanese car over 20 years old - I wouldn't be surprised if it's rusting somewhere and the shell is no longer the shape it should be, or if it's been crashed at some point and something is bent. Or simply that all the rubber mounts and bearings are worn to death and as a result the suspension is more or less flapping around. That would match with your description of one wheel appearing further forward in the arch than the other (castor altering either through *very* worn lower bushings, which would alter toe in and out under acceleration and braking, causing the car to steer, or through the top mount being worn out). Bear in mind that castor altering like this could lead to near zero or negative castor, and the steering trying to fight you, as the self centring effect is reversed.

If the car is heavily bent, or all the rubbers and bearings are gone, it could well be new car time, as the labour soon starts adding up. A car with incorrect geometry can be positively dangerous to drive, so it needs to be looked at.

I was very careful not to mention it in the original article, but Garages A and C are a national fast fit place, who use laser tracking kit. Garage B is a three-man backstreet operation that I normally trust (but that trust could be misplaced). The full suspension check at Garage B only took about

But the fact that two different places checked the tracking (A and C) makes me wonder... though of course the guy at C could have just assumed it was OK.

What sort of place should I be looking? Given my experience with A and C and general comments on this group, I'm not that keen on going to fast fit places. How long does it take to do a full adjustment?

Theo

That is a massive amount of setback! forget tracking you have a problem that tracking alone cant cure.

Fred > obviously there).

Forgot to mention, this was in the vertical direction (from tyre to uppermost extent of wheel arch). Is that still setback? When sitting on tilted ground I'd have thought more weight would be on the lower wheel and thus cause the springs to be more extended on the upper side.

I must find some level ground and measure it with a tape measure, rather than a "two fingers" approach (it was about two fingers on the forecourt, so maybe more like an inch. Probably not more than a centimetre when I tested it later on level ground, but without a tape measure couldn't be accurate).

Theo

No that is a broken coil spring, it is like lowering the suspension and alters the camber angle.

Fred

Given I've had it checked by someone at least vaguely trustworthy, I think something as glaring as that would have been spotted. Is there anything else that might have caused that effect?

Theo

What you actually need is to have a mechanic look at it rather than the 'one step sideways from mcdonalds' lads that work at qwikfit places.

Usually what snaps off is half a coil or so from one end - it's often only noticeable by either geometry changes or by a close inspection of the end of the spring when it's off the car, not nestled neatly into the seat.

I've certainly seen some broken springs that looked good as new until you saw the rusty ragged end when it was dismantled.

It's not always glaringly obvious, I've had the end coil fall off a spring whilst tightening the strut clamp which wasn't obviously cracked.

Bending something.

Interesting idea. Is that something I can likely feel... put the car on stands (so the springs have extended to the max) then put my arm up the spring and feel for the end? Or by feeling for movement on the spring? Or shove a small camera up there (if I had such a thing, which I don't)?

Or do you mean that the spring is actually still pressing agains the upper end (so still mostly working as a suspension spring, and difficult to spot), but being one turn shorter it changes the geometry?

Sounds like getting the spring off would be a right pain...

Cheers, Theo

Springs are usually flattened off at each end , sunno whether this will do justice

That's essentially the problem. Normally the springs a bit rusty as well & the spring rate's dropped a lot as well so it compresses more.

What's the car at the moment?