Tire wear/rotation

In message , Anthony writes

LHD or RHD?

Hi Anthony,

There are a myriad of reasons why the tyres have worn in this way. If the front tyres are as worn as you suggest then rotation should be changed to replacement. Get the tracking checked again anyway as it doesn't take much to knock it out of alignment. If that's okay then check the steering linkages are all straight. Again, if you've been off-road it doesn't take much to bend a track rod.

Other causes can be worn suspension bushes.

HTH

• Swivel bearings

Once you've sorted that lot out think about deviating from LR's recommended pressures.

My experience, which I think is shared by many here and elsewhere, is that you want at least 32 psi in the fronts with the rears a bit higher. It does help with the problem that you are experiencing but won't, obviously, sort out any mechanical issues.

"Anthony" wrote Hello all. Another querry about my wife's 95 Disco 1.

Get the "Toe in" checked as well as the tracking again.

Could you please enlighten us as to the difference between the two?

They are sort of the same but tyres, wheels and suspension form a complex dynamic interelated system. Far more complex than I suspect most people imagine.

Toe in/out I'd say is the static case with the wheels set for straight ahead. Tracking is how the two wheels turn in relation to each other, the inner one has to turn more than the outer.

On or around Mon, 11 Feb 2008 14:22:24 -0800 (PST), Anthony enlightened us thusly:

Front disco tyres at book pressure will wear on both edges, normally. If there's a lot more wear on the outside edge, I'd get the tracking (alignment) checked again.

FWIW, my favoured options for the disco 1 are:

wheel alignment: parallel front pressure: 36psi rear pressure, light running: 36 psi

bit more in the rear if carrying weight, up to 42 even.

Mind, if you got 20K miles from Pirellis, you're doing better than me. Either the kind of driving I do hi hard on tyres, or people are deluded about how long their tyres last. Pirelli Scorpion ATs on mine lasted about

16K miles to the point where I replaced them.

Mind, I'd agree about the grip, excellent in that respect especially on wet tarmac. Goodrich ATs are much harder wearing, but I never felt the same confidence on wet roads with them.

As well as track and suspension bushes jack up the axle and check if there is any movement in the wheel and swivel pin bearings. Check track rod ends at the same time, problems don't always show up when the wheels are grounded.

Carl H

What you are describing as 'tracking' is known as 'toe out on turns' and is a function of Ackerman angle which is non-adjustable. You have confirmed to me that you are actually talking about toe in/out.

On or around Tue, 12 Feb 2008 10:26:21 -0000, "Carl Hadley" enlightened us thusly:

swivel bearing problems would be more likely to cause inner-edge wear. About the only thing that causes outer-edge wear is too much toe-in.

Simply, tracking is the rear wheel following the front ones in line.

Toe in/out is the angle the front wheels (or even rear in some cases) are to the straight ahead, most people think they are always pointing straight forwards but it is seldom the case. Some vehicles need them to point a degree or two in (in other words some are pigeon toed) and some point a degree or two out to the straight ahead.

So tracking might be correct but you may have the wrong Toe in/out set.

In message , Austin Shackles writes

Or if you live in somewhere like Milton Keynes and constantly throw 2 tons of metal round the roundabouts at a great rate of knots.

The OP did say he drove rather hard for an SUV (sic) and hence I asked (not very clearly I admit) whether he drove on the left or the right as this would determine which tyre suffered the most.