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Uneven tyre wear

Hi all.

Just had 2 new front tyres fitted yesterday morning. 2003 Mondeo TDCI on

16" alloys.

Fronts had done 25k, rears 36k (or so, just guessing, but been on 18 months @ 24k/year).

To cut a long story short, the rear tyres are showing more wear on the outer edges than the inner edges (not bald or anything, but 1-2mm or so less tread on the outside edge).

The *front* tyres had a seriously worn bit on the very edge of the shoulder, somewhere where I couldn't even see it making contact with the road! Basically the 45 degree bit between the walls and the tread. At a single point on one wheel, the steel cables were coming through. Sharp edges through a hole in the rubber. The wear wasn't noticeable with the tyres on the car.

They stuck it on their 4 wheel Laser alignment/tracking thing, but the details were within spec.

The front wheels were 1mm toe in (spec says parallel plus/minus 1mm). Rears were in spec to themselves.

Front to rear were also within spec - one side was "4.5", the other "5.5". I'm assuming the spec is something like 5 plus/minus 1 or 0.5.

So basically, the tracking was OK, all around the car. On the high side of the spec, but within spec.

The fronts had been on 12 months, the rear 18 months. They'd done about

25k and 36k respectively.

The front *had* required the tracking to be done about 6 months ago.

What I'm assuming at the moment is that prior to the previous tracking being done, there was quite a lot of wear. The cables through the one tyre was on the kerb side of the car. I remember pulling up to the house a couple of months back, and getting up onto the kerb a little harder than usual. I'm wondering if the combination of the heavy wear and the impact would have broken the cables. There were definite ends poking out.

Does this sound like a plausible situation? Could there be a problem somewhere that would now show up in tracking/alignment?

Thanks.

Pete.

Reply to
Pete Smith
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Pete Smith (pete snipped-for-privacy@lethe.org.uk) gurgled happily, sounding much like they were saying :

What car, what age?

There's not a helluva lot you can do to adjust the rear tracking.

If the tracking's out, then the edge is going to wear badly. If the edge wears badly, it's going to go through the tread, then the rest of the rubber into the reinforcement, which will - eventually - snap as they wear...

This was the OUTSIDE edge...? You wanna be checking 'em more often, Pete...

Reply to
Adrian

So the tyres were in a seriously illegal condition? You know, the condition that Road Wars makes a meal out of?

Reply to
Conor

If there's suspension wear it will lead to tyre wear but may show within limits results on the alignment. The outer edges usually do wear a bit more because of cornering.

Reply to
adder1969

2003 Mondeo TDCI 16" alloys (like it said on the original!)

These have adjustable tracking on the rears. There's an arm connecting the hub to the rear sub frame, in the middle of the car.

You undo a nut, pull a bolt out, fit the appropriate washers, refit the bolt, do it up, and depending on the position of the washers, the angle of the rear wheel WRT the rest of the car can be altered.

The small difference isn't going to bother me if it keeps going, because if the tyres last 50k, and are still legal, I'm not going to have sleepless nights replacing them a few months early.

No, on the *inside*!

To recap.... the rears have 1-2mm less on the *outside* of both of them (we're still looking at 5mm or so on the inside, and 3 or 4 on the outside.

The front had bad wear on the *inner* shoulder of the tyre. Like the rear, there's a little more wear on the outside edge of the tread than the inside edge.

I check them every couple of weeks, but it wasn't obviously visible, because it was on the shoulder of the tyre, i.e. Point C below.

| | | | | | \_______/ A BC

Even on full lock, the wear was "behind" the bit you can see from the outside. I saw there was 1.6mm on the outside edge (A above), 2mm+ on the inside edge (B above). The serious wear was at point C, invisible without taking the wheels off, or getting under the car.

The reason I know they needed replacing was because I *do* check them. There was only a very small amount of tread badly worn (the very edge), so as far as the 1.6mm over 75% goes, there was *plenty* of spare (in retrospect)

The bit that had the cable showing had the cable still deep inside the tyre, poking out. It wasn't as though there was any cable showing anywhere else. It looked like the end of a sliced steel hawser, not the normal "edge on" when a tyre's down to the steel. That's what made me think it was physical damage had broken the steel, and driving had forced it to the surface.

I'm going to be keeping a very close eye on the front ones, for any more of the same wear. If I see it, it's going in (somewhere!) for a suspension check. I'm going to have to use a torch, and actually crawl under the car though!

Pete.

Reply to
Pete Smith

Had a similar problem with my Mondeo 1.8 (2002). Seems quite common according to independant tyre man. Normal tracking equipment unsuitable. It was the rear toe-in that was out. Needed to go on a computerised 4 wheel alingment thingy, (main Ford Dealer didnt have one, they admitted that they were unable to rectify). Cost a fair few squids to rectify. The garage that did it used shims.

Reply to
Merryterry

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