Outer Limits 4x4 Board

Anyone seen anything like this before???



31" Simex ETs on my sierra. The coopers i had on for 2 years before these never did this... is it purely to do with the tread pattern and driving on road??? You can see where the dust on the tyre has disappeared that the front 3mm or so of tread is hitting the road harder than the back - but what gets me is the strange lines where theyre wearing???

Weirdest of all though is its the back of the tread block thats wearing, not the front which you'd assume cops more abuse as it hits the road first.

Thoughts?

how much pressure do you run

I have a set of 35 inch Simex ETs which I got second hand, and they are worn in a similar way.
It will be good to see what people think cos I've had no idea.

Cheers

spinnin the wheels in the wet

so they are new tyres ???
or 2nd hand ???
have u had a wheel alignment recently ???
doin a bit of off roading will chuck the balance and/or alignment out

Oh yeah i should have mentioned - its only doing it on the front!!!

I run 20psi - which is pretty firm for a sierra and the simex's (the sidewalls are stiff as - had them at 5psi on the weekend and they only just bulge!).

EDIT: yes - wheels are aligned and i have also tape-measured them recently as well to be super sure.

It could be the wheel bearings.

jacking the tires to 28psi could be worth a try, this is what a mate runs in his zook after a bit of mucking around and probs with tire wear, not sure what sort of wear though

cheers

If it was all 4 wheels I'd be leaning towards tyre pressure but as it is only the front I'd have a good look at the front end. Check the wheel bearings, rod ends, shocks, etc.

Also how long ago was the alignment done?

Does the front end feel like it is bouncing (not absorbing the bump) when you hit bumps on the tarmac. Have you bent a front spring.

Cris

unbalanced tyre wear like what you have showen appears due to brake bias not set correctly i would look at your brake setup and make sure your not biased to much to the front

the folding of the tread and wear lines aslo show this as the front tyres are working hard at slowing the car its not to disimilar to doing a burnout but its the revers effect

Your tyres/rims are out of balance and/or your shocks are rooted mate its one or the other.

RIMS: definitely out of balance - theres a lot of mud in there! but i do clean it often as possible

ALIGNMENT: last done bot 3 months ago, but measured only 2 weeks ago

BRAKE BIAS: definitely possible - mud in the rear drums makes for terrible rear braking capacity - but as with rims, i try keep it as clean as possible - worth looking into though.

SHOCKS: only 2.5 years old, definitely not the shocks. still drives really well.

SPRINGS: front leaves are ever so slightly sagged, but not bent.

WHEEL BEARINGS: both fine

PRESSURES: 20psi is even pushing it, probably should be more like 15-18 - i chose 20 for sidewall stability.

I think brake bias is the most likely culprit as thats the only thing thats recently changed (new rear shoes, cylinders and calipers) perhaps the rears have fallen out of adjustment since being fitted?

Had the same on my Zook with the 235/75R15 MTRs on there. Rear of the tread blocks (right hand side of photo) wearing quicker than the front. Both front and rear tyres. This is at about 30,000km ... front of tread is 12-13mm; rear is 10-11mm. Always ran them at 20psi too.

had the same problem with my old hilux with a set of coopers, and the only answer was rotation every 3000klms and the tyres were fine after that, just a pain in the ass

rob

I have had simillar wear issues on my zook, with MTR's and BFG muds. I havent noticed it on my swampers, but I dont drive them on the tar much and they get swapped round a fair bit.

Layto....

How long since tyres were rotated?

This is normal heel-toe wear for bulky treads. different tyres will do it to different degrees on different vehicles.
However ALL tyres on ALL vehicles WILL do it.

To fix, rotate your tyres.

Minor things will change the effect, such as shocks and alignment etc. but the main fix is rotation.

As it is wearing more in the centre I'd also say that you could drop the pressure a little, and check with the 4psi rule.

You say you had wheel aligments, but what are the spec's? post up or pm me the camber castor toe and also the rest of the spec if have like scrub radias toe out on turns SAI whatever you have, check your shocks and balance very important.

Brakes And tyres.
look at any dirt bike that has been ridden on the road. The front tyre will look the same

Eddy wrote:How long since tyres were rotated?

This is normal heel-toe wear for bulky treads. different tyres will do it to different degrees on different vehicles.
However ALL tyres on ALL vehicles WILL do it.

To fix, rotate your tyres.

Minor things will change the effect, such as shocks and alignment etc. but the main fix is rotation.

As it is wearing more in the centre I'd also say that you could drop the pressure a little, and check with the 4psi rule.

What Eddy said.

Tyre wear due to tread block movement.
Happens to some degree on any agressive tread tyre.
Have a look at a tractor tyre if it does alot of bitumen running, one bar is worn, the other is not.

Rotate side to side, so that they even out the wear.

Trains

it looks like "feathering" id be checking the wheel bearings, seen a lot like this on trucks and so forth with high k's, but seeing your are on simex's soft compund, id be looking ad adjustment

bump the pressure up to the higher end of the tyres inflation scale when on the roads and they will slop wearing like that....... it stops the tread sort of "folding" down onto the road surface and wearing like that.

also im not sure how a sierra front axle works but jack up car and check the wheel bearing play , then get some one to push as hard as they can on the brake, and check again, this is like checking the "wheel bearing" then "king pin" for wear, i spose its more scolloping instead of feathering

Cheers
Duane.

i had sort of same thing, mine was wrong caster but thats in rangie with a lift

Eddy wrote:How long since tyres were rotated?

This is normal heel-toe wear for bulky treads. different tyres will do it to different degrees on different vehicles.
However ALL tyres on ALL vehicles WILL do it.

To fix, rotate your tyres.

Minor things will change the effect, such as shocks and alignment etc. but the main fix is rotation.

As it is wearing more in the centre I'd also say that you could drop the pressure a little, and check with the 4psi rule.

the tyres in question are directional, so rotation will only consist of moving tyres front to back on the same side. Would this still fix the problem?

mike_nofx wrote:
the tyres in question are directional, so rotation will only consist of moving tyres front to back on the same side. Would this still fix the problem?

It will help but this problem will never be fixed. it is the way of tyres, and the price you pay for running chunky rubber on road.

I have the same happening on my 6ton truck, with highway tread pattern. unfortunately I'm stuck with it as I run clean skins on the steer and caps on the drive. all I can do is rotate the fronts but I can include a spare, as I have both front and rear spares. Again, it is the price we pay ... ...

That your tyres are wearing in the centre suggests to me that tyre pressure may be a little high also.
I would suggest a search on "4psi rule" but it won't work here will it ... roll:
check the pressure before you leave home. 1/2 hr down the road, check again. they should be 4 psi higher.
If they are less than 4 psi higher. drop the pressure by 2 - 4 psi
if more than 4psi higher, add more air.


Be aware that the others will soon begin to look a bit the same.

Your next step then would be to strip the tyre from the rims and refit the opposite way on the rims. you can then do another two rotations.

Thanks guys... rotation is definitely on the to-do list as well as brake adjustment.

With 4psi rule - not so effective for me - like i said further back, lower than 20psi on the road and the sidewalls get quite wobbly, and cornering is a bitch... but its not riding on the centre, i actually get quite a lot of the tread touching the ground.

The simex tyres are also a very rounded design - as in, the centre blocks are higher than the side ones (domed) when compared to my old coopers which were quite square.

gonfellon wrote:i had sort of same thing, mine was wrong caster but thats in rangie with a lift

How can caster wear your tyres?

chunks wrote:

gonfellon wrote:i had sort of same thing, mine was wrong caster but thats in rangie with a lift

How can caster wear your tyres?

HOW you ask? i'll tell you.
Castors helps the car to drive straight if you have more castor on the right here in Australia/right hand drive then the car will want to pull/drift left, so there for you hold the steering down a bit to the right to make it drive straight so there fore your tyres are grading so you'll get tyre wear...left front outside wear and right front inside wear, and sometimes it can give you a sign of toe wear. There is more to wheel alignments then what people think, alot of shops just toe and go, hope that clears it up.

Interesting. I always try and have a bit more caster on the passenger side when I'm aligning a car to get it to drive straight, but haven't really noticed tyre wear from caster. Usually its a camber or toe issue, or incorrect tyre pressures, worn components etc.