Rear wheel alignment

Bob,

Are you sure the tyre(s) haven't been rotated? (swapped front to back)

Noticed mine had at the last service, even though I had instructed the Service Company not to.
I think it is just an automatic task that they get into the habit of doing by following a check list.

It does sound like the rear tyre was on the front left for most of it's life. I don't think you have any camber or toe adjustment on a rear rigid axle

Its a bugger - I got 80k from my first set on the Jack - all shoulders were thin while there was some meat left in the middle. With even wear I may have got to 85-90k tops. The stony outback trips take a big toll on the rubber. I'm running my new set up in pressure to try and get more even wear across the face. The inside shoulders of this new set are wearing a bit quicker on the front than the others so it goes in for a check next week. Gotta stretch that lifespan - they cost so much !

Bob, could it be a rear wheel bearing that needs adjustment ?

80,000 is pretty good milage from a 4WD tyre. I have only beaten that once. I got 90k out of BFG AT 33 inchers and they still had a bit left.

If your rear end is out it could be the diff alignment. Most rear ends (all Toyota solid axels) have a "centre bolt" that comes down from the axel and goes through all of the rear leaf springs to locate them centrally. It is kind of like a stud that is a few inches long. They can break off or rust off if they have been dipped in salt water as they are not very thick. They can also be broken after serios off road travel on really rough terrain. When driving with a broken centre bolt it feels like your alignment is out and you have to correct by turning the steering wheel off centre in order to maintain a straight line.

When travelling behind a vehicle with a broken centre bolt it appears that the rear wheels are not following the line of the front tyres. It also looks like the vehicle is driving a little "sideways" down the road.

To see if this is the case hose down your driveway and drive through the puddle. If there are 4 tyre marks exiting the puddle onto the dry surface then this would indicate a mis aligned rear end. If there are only 2 tracks then the alignment is OK. Another way to sus it out is to get someone to drive the vehicle in a dead straight line and follow behind to see if the vehicle is out of alignment.