What would cause this tire wear?

[tip]

I just got new tires for my K3500, and want to make damn sure they don't end up looking like the ones that came on it:





HUGE cups on both sides and lots of outside wear as you can see. I'm planning on doing king pins here shortly, plus an alignment. Just want to make sure there's nothing else I should do. The rear tires have the same amount of miles and look like 80% tread is left...

[garmar]

You should pop off your dif cover and see if the spider gears are welded. If so that would cause your tires to get pushed through turns. Provided nothing else is worn or out of spec.

[Stocker]

Aggressive mud tires like that will tend to cup when mounted up front. Biggest problem I see is all that extra wear on the outer part of the tread. Alignment should fix it, could just be toed-in too much. Hard cornering and low air pressure can make it worse too. If you rotate the tires every 5K miles, you'll get a lot more out of the set.

[obijuan]

That's pretty atypical of a solid axle. Are you sure they have been there on the truck since new?

The welded diff and low pressure weighted turns can do it if it was a plow truck? Lastly it would be camber which can be fixed by a spindle shim or an offset kingpin bushing.

[Bigdav160]

Since it's both tires, I'm with Stocker, toe is too positive

[OrrieG]

Originally Posted by obijuan

Lastly it would be camber which can be fixed by a spindle shim or an offset kingpin bushing.

I thought the only adjustment was toe on those front axles, hadn't considered offset bushings.

[beardface]

Originally Posted by garmar

You should pop off your dif cover and see if the spider gears are welded. If so that would cause your tires to get pushed through turns. Provided nothing else is worn or out of spec.

I'd jack up one wheel and give it a spin before pulling the diff cover. Unless you just feel like taking a peek in there.

[Stocker]

If the front spiders were welded, wouldn't the truck be nearly impossible to steer all the time?

[Bigdav160]

Not if the hubs are unlocked

[burnin oil]

The factory had the tires tipped in slightly at the bottom and slightly inward also. It does good for handeling and tracking straight but eats tires, especially when pushed hard. The only way to fix it that I know of is to have a tappered shim added to the knuckle. The only time I have seen them used is on a bent axle though.

[LONGHAIR]

Unless it has some mechanical issue, like a bent housing or spindle, it is probably just under-inflation and lack of rotation. The tire tilt into a turn pretty heavily and this puts extra pressure in the outer edge of the tire. When under-inflated the outer lugs of aggressive mud tires get worn on the trailing edge, making them look like saw teeth. Many guys run them a lower pressure though to keep more of the tread in the street. If you inflate them to 30-35 PSI, they wont wear like that, but the outer lugs will not touch the ground on hard pavement either...

BTW, if the hubs were unlocked, welded spiders wouln't make any difference.....other than still being a stupid thing to do to a truck.

[croatoan]

It's toe in. Jack up each side and mark a center line on the tire by rotating it and marking it with a peice of chaulk. You also need a tape measurer, 5' peice of angle iron, 2 framing squares and 2 C-clamp vise grips. Mark center line on both tires, clamp one square to one end of the angle iron and line up the outside edge of the square on the pass side chaulk mark, go to the drivers side line up the outside of the second square with the chaulk line and clamp it to the angle iron. Go back and make sure both sides are on the marks, adjust if needed, when happy measure with a tape. Write down the measurement, lay down the squares and angle iron rig and move it to the back side of the tires you should be able to slide it under and stand it up without unclamping it, repeat what you did on the other side of the tire. If the rear measurement is less than the front it's toed out (will wear the inside of the tires). If the raer measurement is more than the front it's toed in (and like yours will wear the outside of the tires).