OT: Wheel tracking - how accurate does it have to be?

[Jim K..]

"Bending it"? No that's not part of a 4 wheel alignment ;-)

[Jim K..]

Amazon? Or GIYF....

[Dave W]

I have just had my car serviced. The garage sends out videos showing inspection of the underside, and in mine the technician showed the front kerbside tyre as having only 3mm tread but said will probably be all right till my next service as I only do 2000 miles per year.

I then got a call from the garage owner saying I needed the tyre to be changed, and that the tracking was out and needed tow-in adjustment to prevent one-sided wear observed on that tyre, which I agreed to.

When I got the printout from the tracking machine I was astounded at the manufacturer's limits on the settings. The front wheel states tow limits of 0°00' to 0°10', and my wheel before adjustment was 0°23'.

After adjustment it read 0°05'. In other words they adjusted it by 18 minutes of arc, about a third of a degree.

I cannot believe that such a small adjustment will have noticable effect on tyre wear. It seems to me that manufacturers have such limits because they are easy to achieve, but users should be given much wider limits before adjustment is needed.

I've now researched this interesting subject, but can find no scientific treatment. The first 10 pages on Google are filled with garages offering tracking, laying it on thick about how important it is. The tracking machine's website has two videos of garage owners saying how quick and easy it is to check alignment and offer customers adjustment, and the added income paying for the machine many times over.

I was charged £145+VAT for it, and looking at my video again, there was no characteristic toe-in wear. I think I've been had! Any thoughts?

[Andy Burns]

I think you have at that price, F1 Autocentres will do the alignment check for free and something like £30 to re-align if needed.

[Michael Chare]

DIY is quite possible all you need is a measuring tape some spanners and perhaps some knowledge of trigonometry. Long time since I last did this though.

[Dave Liquorice]

I wouldn't like to bet on it. Though compared to tyre pressure it's probably lower. Incorrect tracking normally shows itself as the car pulling slightly to the left or right. Correctly aligned and on a straight, flat road, and decent speed (50mph+) the car should go in dead straight lilne with hands off the steering wheel. The chances it will slowly drift left or right as roads aren't flat, repeat a few times on different stretches of "flat, straight road" and see if it consistantly drifts left/right at about the same rate. Oh and make sure all the tyre pressures are correct (note that might not be the book value, "correct" to produce even tyre wear).

At £145+VAT for a simple tracking check and alignment, you've been had. But was it a full 4 wheel alignment check and adjustment? Bear in mind that a full 4 wheel alignment means putting the car in a jig and bending it to align the wheels, normally only done after an accident.

At the begining you say there was...

[Harry Bloomfield]

Dave Liquorice laid this down on his screen :

Never heard of that, my car has proper adjusters for the rear alignment.

[Andy Bennet]

Kwik fit tried this out on me last time I had new tyres fitted. You got a "free" front and rear tyre tracking check. (I didn't know the rear wheel tracking could be adjusted on a whim). When complete the operative came into the waiting room with a sad face and asked me to come and look at the measurements on screen. The machine handily hightlights any out of range results in bright red to add to the drama. Like you I had two front wheels misaligned by several 10's of minutes of arc. I was informed that to adjust them would cost £145 + vat - but I could drop in as many times as I liked over the next year to get them checked and adjusted free of charge. I figured I would take the misalignment on the chin, and if one of the tyres did need changing premerturly the £145 + vat would more than cover the expense!

[T i m]

<snip>

Whilst I understand that correct, aren't there also vehicles that have 4 wheel tracking / geometry adjustments under normal use?

Such adjustments being required after parts were replaced (suspension related bushings) or the ride height changed etc?

After a minor accident on the kitcar, I noticed excessive rear wheel 'tracking' type tyre wear and when KF couldn't measure the error themselves, they let me use their kit and measure it myself. ;-)

1.5 deg toe-in (when it should have been zero) knocked out a fairly big / new tyre in less than 1000 miles.

Cheers, T i m

[Chris Bartram]

That's not true far all cars. My last 2 cars have had independent and adjustable rear suspension- and indeed there have been revised settings issued after the cars were made.

£145 seems a bit steep for full alignment compared to my independent garage, but at dealer charges it doesn't seem too bad, I suppose. It's not a five minute job.

FWIW I'd never allow one of the cruddy tyre-fitting places that do tracking for £20-30 near my car as historically they've f***ed it up every time, and/or neglected worn/damaged components.

[Chris Bartram]

More accurate would be that come cars only give you the option of replacing (or re-aligning (bending!)) bits- for instance many FWD cars have non-adjustable rear axles. (Golfs 1-4, IIRC, for example)

[The Natural Philosopher]

Your belief is not invited.

I can assure you that that level of misalignment will cause uneven tyre wear

[The Natural Philosopher]

No, it doesn't.

Most cars have adjustments on the rear wheels.

[Chris Green]

It's 'toe in'

[Pamela]

[Vir Campestris]

Most likely left. Most roads have a camber - higher in the middle of the road than at the kerbs - to make rain run off.

Andy

[Dave W]

You can assure me as much as you like, but I want evidence. Do you run a garage?

[Dave W]

I'm glad to hear that Kwikfit charges are similar, and I agree with your reasons for not having it.

[Dave W]

Wear, but not the corner wear typical of toe misalignment. They only adjusted the toe on the front wheels - none of the other adjustments that would have been needed to make the printout results all green.

[Dave W]

I believe you, but it wouldn't be to within a few minutes of arc. Until I have evidence to the contrary I don't believe such accuracy is needed.