Odd rear tire wear (2 Viewers)

[PeterTheBeater]

Got a 97 FJZ80, running 35” Cooper STT Pros (E) about 1.5yr old. Got Fox 2.0 extended shocks, about 1.5yr old. OME mystery springs. The rear tires are having a funny wear pattern, almost feather like. Can’t notice anything in the front, maybe some odd wear before the rotation. No vibration or other issues that I can feel. Running about 35psi. These two rear ones were rotated from the front 3000mil ago. Any takes?

 

[ppc]

Got a 97 FJZ80, running 35” Cooper STT Pros (E) about 1.5yr old. Got Fox 2.0 extended shocks, about 1.5yr old.

Age is insignificant, how many miles is going to be more helpful.

 

[PeterTheBeater]

Age is insignificant, how many miles is going to be more helpful.

No more than 15k

 

[BILT4ME]

Got a 97 FJZ80, running 35” Cooper STT Pros (E) about 1.5yr old. Got Fox 2.0 extended shocks, about 1.5yr old. OME mystery springs. The rear tires are having a funny wear pattern, almost feather like. Can’t notice anything in the front, maybe some odd wear before the rotation. No vibration or other issues that I can feel. Running about 35psi. These two rear ones were rotated from the front 3000mil ago. Any takes?
View attachment 3414472View attachment 3414475

How many miles ago did you rotate them?

What I see there is typical front tire wear, then rotated to the rear and the rear is straight and flat, so the pattern looks off.

 

[PeterTheBeater]

How many miles ago did you rotate them?

What I see there is typical front tire wear, then rotated to the rear and the rear is straight and flat, so the pattern looks off.

Interesting,

These two rear tires were rotated from the front 3k miles ago. When looking at the front tires, the wear “looks” even, meaning I don’t these contact witness marks.

I could be wrong, but I’m assuming the darker spots is where the tire is wearing more.

 

[vfrer]

They looked cupped. Could be several things.... suspension worn, steering worn, balance, alignment or just bad tires too

 

[alia176]

I have had similar issues for many years, regardless of the type of tire or rotation. Full time 4x4 contributes to the front tires due to the wheels pulling and the toe adjustment needs to right on the money. However, I've been 2wd for about 18 years and I still have similar wear pattern on all four tires. My suspension is always fresh, including bushings and such. For me I try to rotate the tires as frequent as possible and also do the chalk test to make sure the pressures are correct.

 

[Tower1]

school me on this chalk test

 

[alia176]

Chalk test - steal a fat chalk from your kids then draw a line across the tread, then bring it down to the sidewall just a tad so that you know where the line is suppose to be at. Then go for a drive, do some figure 8s, pull over and look at the line. If your tire pressure is good, the entire line should disappear evenly. If not, then adjust your pressure accordingly to make the line disappear evenly.

 

[Tower1]

Got it. Cool trick , thanks

 

[mudgudgeon]

Got it. Cool trick , thanks

If chalk is gone on the middle, but not the edges, lower the air pressure.
If its gone on the edges, but not the middle, increase air pressure

 

[leonard_nemoy]

Also when doing the chalk test remember the optimum psi will most likely be different for the front and rear tires. I do the test on 1 front tire and 1 rear tire.

 

[Rifleman]

If chalk is gone on the middle, but not the edges, lower the air pressure.
If its gone on the edges, but not the middle, increase air pressure

This is correct, i had the same type of problem, i went from 35 psi to 55 psi for highway use, and my strange wear pattern went away As an added plus of the extra tire pressure i went from 9 to 10 miles per gallon to 11 to 12 miles per gallon

 

[mudgudgeon]

This is correct, i had the same type of problem, i went from 35 psi to 55 psi for highway use, and my strange wear pattern went away As an added plus of the extra tire pressure i went from 9 to 10 miles per gallon to 11 to 12 miles per gallon

And how are your kidneys?

I've always settled on pressures in low 30s.

I'd rather cop some tire west and a softer ride than have my fillings and kidneys shaken loose.

There's always a trade off I guess

 

[alia176]

This is correct, i had the same type of problem, i went from 35 psi to 55 psi for highway use, and my strange wear pattern went away As an added plus of the extra tire pressure i went from 9 to 10 miles per gallon to 11 to 12 miles per gallon

35 to 55 psi?

 

[robnicko]

Looks like mild sawtooth effect or ramping of the tread. Run your hand forwards and backwards across the tread and youll feel it
When you rotate them put the lower leading edge so that it makes rotational contact with the ground first as opposed to the higher edge. They will then even out and slowly start sawtoothing again at which point you rotate them again
Key is to always have the lower edge contact the road first when driving forwards

 

[LandLocked93]

On the fringe side of things, a bent axle tube can do similar things I believe.
But perhaps it's just worn control arm bushings causing the rear axle to yaw under accel/decel?

 

[robnicko]

On the fringe side of things, a bent axle tube can do similar things I believe.
But perhaps it's just worn control arm bushings causing the rear axle to yaw under accel/decel?

true, play in wheel bearings, incorrectly adjusted LSPV etc. Many things but looking at the tread blocks which are quite aggressive they cop a hiding driving on sealed roads which exacerbates the issue

 

[Rifleman]

And how are your kidneys?

I've always settled on pressures in low 30s.

I'd rather cop some tire west and a softer ride than have my fillings and kidneys shaken loose.

There's always a trade off I guess

My kidneys are just fine, and at a cost now a days of over 250 to 300 dollars a piece for new tires i want to get as much wear and mileage out of a set of tires as i can

35 to 55 psi?

The tires I'm running are M/T (large open tread blocks) and have a max PSI of 80 printed on their sidewall, so running 55 PSI for highway use is far from the tires max pressure, When i go off road i air down to 15 to 20 PSI, then air back up when i hit the pavement

 

[mudgudgeon]

My kidneys are just fine, and at a cost now a days of over 250 to 300 dollars a piece for new tires i want to get as much wear and mileage out of a set of tires as i can

No criticism here.

I'll also say, I guarantee I pay more for tires than you would in USA. There's the downunder freight tax, and shìtty conversion rate that slaughters us on anything imported.

I prefer a softer ride than you'll get at 55psi, but it's traded for this wear, and a more vague steering feel.
Difference in pressure can be felt in steering behaviour and bump absorption.

Different tires I've had have been comfortable and still responsive in low to mid 30s, or harsher, but more direct at low 40s psi.
Add more air if you're heavily loaded, towing, or doing a long highway trip.