Odd Tyre Wear Pattern

[solmanic]

I just had a wheel alignment and tyre rotation done last week and the guys who did it warned me that I had an uneven wear pattern on both front wheels (now on the back). There is an undulating wear pattern all around the inner part of the tread - quite noticable to the naked eye.

I got them to check the suspension to see if they could find out what exactly caused this. They say the shockies and bushes are all fine - the only thing is the front castor bushes are worn, but not enough to cause the amount of wear exhibited they reckon.

Any ideas? The tyres are original and have done 65K over approx. 4 years. Mostly bitumen and off-roading has been gentle (I am a wuss).

[100I]

dare I say it?


PICS

[solmanic]

Here is the worst one - not that easy to capture in a photo but you can just see the humpty-dumpty profile on the far (inside) edge of the tyre. This is the rear left which was on the front right. Both ex-front tyres have this but the front right was much worse.

http://img470.imageshack.us/img470/3276/070904lrtyrewear004bm7.jpg (http://imageshack.us)

[langy]

It might be your shocks. Even though they say they are fine, my front set of Pirelli Scorpions went like that after 40k. I had 3 year old OME shocks ( on it when I bought the car) , but when I changed them for a new set, I found that they had lost gas pressure. 30k later my new front pair of scorpions are still good, and I should get at least 80k out of them like the rear set have done.

[Blknight.aus]

looks like shock wear...

it can happen with some styles of shocks if they get areation of the oil but more than likely its the rubbers gone spongey... with a normal check they will seem ok but when you pull them out they'll be more like taffy than rubber.

check the locating arm rubbers and pan hard rubbers while your at it.


secondary causes cover

wheels out of radial true, this is more noticable if the ripples are on one part of the circumfrence more than the other. harmonizing will carry the ripple around the tyre and some can get transmitted to the other wheel on a beam type axle. (but usually secondary wear requires suspension damage.)

Failing bearing/top swivel pin wear. if the inner bearing is failing (spinning its races or has a failed roller) it will oscilate the wheel.

IF the top pin is worn in spots (out of shape) or incorectly seated this will allow a similar effect.

All of the secondary type causes will have other symptoms that can be found if you know what to look for .

[tombraider]

I concur with BlkNight....

Also emailed it to a tyre store owner mate of mine (specialises in 4wd rubber) and he said immediately...

In order of probability...

Shocks...
Out of round tyre
Imbalance
Bushes
Bearings in Swivels...
Bent diff

So there you go....

[100I]

The cupping would be from uncontrolled movement, be it somewhere in the wheel bearings to suspension wear.
There is also signs of underinflation judging by the wear on the outer shoulder, the lack of feathering suggests the w/alignment is not the culprit.

[Blknight.aus]

or cornering too fast :)

[rovercare]

or cornering too fast :)

Wears the outside edge, not the inside, don't ask me how I know:angel:

[beforethevision]

I had a set of Goodyear's do that, all 4 after about the same distance. I swapped to BFG's and it never came back.

[solmanic]

There is also signs of underinflation judging by the wear on the outer shoulder,

Interesting - I have always thought that the pressures recommended for front tyres on a Defender seem too low. From memory it is 28PSI in the manual but I regularly run 30-32PSI. They still "bag" a lot so should I be running higher pressures?

[solmanic]

or cornering too fast :)

HA! That's a funny one.

[JDNSW]

Interesting - I have always thought that the pressures recommended for front tyres on a Defender seem too low. From memory it is 28PSI in the manual but I regularly run 30-32PSI. They still "bag" a lot so should I be running higher pressures?

Interesting - the my 110 has 35 as the minimum for unloaded and low speeds (apart from allowed reduction for sand etc). Also interesting is that the pressures are higher in the Australian supplement and the placard in the vehicle than in the UK owners manual!

John

[100I]

Interesting - I have always thought that the pressures recommended for front tyres on a Defender seem too low. From memory it is 28PSI in the manual but I regularly run 30-32PSI. They still "bag" a lot so should I be running higher pressures?

Dave is right, it's the balance of tyre pressures to suit driving style. 32 or even 28 might be fine for someone who drives very conservatively. That's not saying you're a reckless hoon, just you obviously tend to keep corner speed up, so the tyre is rolling under a little and scuffing the outer shoulder. Higher pressure will stand them up better.
I run fairly lowish pressures myself, in the interests of ride quality. I'm not reckless either but I'm no slouch.
I keep nasty wear patterns at bay but I don't get too concerned if they don't wear dead flat. It's all very much personal choice.
For me, I just put slightly cheaper tyres on more often, and I usually don't wear them right out for that matter (except sportsbike rubber that's lucky if it achieves 10000k). Rubber hardens with time anyway so a 5yr old tyre is well rooted in my book, but again that's my choice.

[procrastination inc]

I had exactly the same wear patterns on the back of the disco I bought last week.

I had a set of new tyres fitted and asked the guys there to look for wear in the suspension and diff while they had it on the hoist.

They report excessive sideways slop in the rear.

so Ill do all the bushes next weekend

what are super pro bushes like?

http://www.fulcrumsuspensions.com.au/fulcrumCat/img.php?id=2988

front and rear right shocks seem like they aren't coping either.

Any one know about Koni heavy track are like?

I don't need serious off road gear just good stuff that works well and lasts long. This truck is for 90% highway commute, 6 snow trips a year and the occasional bush track tour/camp

[DEFENDERZOOK]

if the back tyres are scalloped on the inside edge......this indicates shocks arent up to the job any more.......