Uneven Tyre Wear 79 series

He is running too much pressure, with radials the centre of the tread is stronger than the sidewalls because of the steel belting so the side stretch more under pressure and form an inverted u shape with the side trying to carry the load. I am running 235's and the running pressure is about 30psi. Barnray
PS CHANGE TYRE REP He is a retired bank manager.B

You also need to tell us what sort of wheels he is using as split rims with inner tubes etc will require higher pressures than radial on one piece rims in my experience.

Cheers,

Mark

Craig

Are these pressures being set with the same gauge all the time, either his own or at the same service station, or is it at different service stations? If it is the same gauge then it may not be accurate. Everything I have either read or been taught at TAFE about tyre wear points to the same type of wear on the outside edges of a tyre as being caused by under inflation. His 55 to 60 could be way under that if the gauge is out.

What was the wear like prior to fitting the new springs? I have no idea if they could be causing the problem but after working for many years at three different Toyota dealers, I have seen a hell of a lot of unusual problems caused by non genuine parts. I find it hard to believe they could be the problem but I would still be inclined to put the original ones back in and see what happens.

Also run factory pressures if he is not already doing it, providing the tyres are stock size and specifications. The car is not overloaded so there is no reason to go outside them. I do this with mine, a Hilux, and the wear is perfectly even. The stock tyres on it have a maximum pressure of 65 psi at a load of over 1100kg per tyre. Toyota recommends 25 to 34 at the rear depending on the load. The car is never fully loaded so I keep them at around 28 to 30 and there are no problems.

Another thing you could try if the problem continues is ring the technical information number for BFG. I have never hesitated to ring the manufacturer of anything if I want to know anything about their product. It makes no difference whether it is cars , Weet Bix or anything in between, I have always found them to be very helpful.

The link below from Bob Jane gives some useful information on tyres including wear patterns.

Site Link

Brian

Stock pressures on my Troopy by the manufacturers plate is 55 to 60psi on the rear with 750/16 tyres. That is what we run

Stevesub

Thankyou Gentlemen for your input.
The 79 series has standard steel rims - same as 100 series. I think it was a 2000 model.
The tyres are All Terrains
The Springs were actually modified at 1000km not 10000km. A new leaf added and the existing leafs were reset with a little more curve. It was found the sag was excessive for the load which was well within specifications. The spring works commented that they were doing several new Landcruisers each week at the time. I believe toyota upgraded the springs on this model shortly after.
The same tyre guage was used which we will endeavour to get checked in the next few days.
It was the actual BFG rep who declined any claim stating underinflation was the cause.
The same load, a glide on van, was used for many years on a 75 series ute before this with BFG's and the same tyre pressures from the same guage with no abnormal wear occurring.
Regards Craig