Inner tire wear - rear solid axle

[JHZR2]

Any ideas? Top pic was driving through a patch of grit I had rinsed out after hauling a ton of 3/4” stone.

Rear axle, 96 Ram 2wd.

I wouldn’t rule out bent axle, it is very easy to load this truck heavy, because of its special large bed, and it was also set up (hidden fifth wheel in the bed) and towed heavy by the PO for around the last 330k miles. That said, it tracks very nicely down the road, tires aren’t too noisy, etc.

Tires have kind of always been like this since I owned it, and I’ve run it pretty heavy, 50% of the time with 2000-4000 lbs in the bed. I thought it might be shocks, I snagged a close out set of Gabriel Ultras and it rides much better. But tire wear hasn’t gotten better in ~2000 miles. Is that too short a time?

 

[oldhp]

4 wheel alignment will tell you for sure. How many miles on tires at this picture?

 

[wpod]

Wear some where.

 

[mattd]

Worn leaf spring bushings or the axle housing is bent/twisted. I would have it put on an alignment machine to see how bad the toe really is, and which way the axle is actually pointing.

You’d need to rotate the tires to see if the wear continues on the others.

Are there full floating hubs on the truck?

 

[RooflessVW]

If the shocks fixed it, the wear won't get better; it just won't get worse.

 

[MParr]

Like mattd said. I would also suspect fatigued springs. Is the frame bent? A bent frame or your axel not being square to the frame could cause this to. Get someone to drive it for you and you follow in another vehicle. If it runs down the road like a bulldog, it darned sure ain’t square. Another thing is your limited slip staying locked up.

 

[Rand]

its not just inner wear, its the worst there, but the tread blocks are worn cupped/scalloped?
ie it looks like someone randomly sanded the tread blocks.

is it possible the front end is starting the wear pattern?.. and you rotated them?
What do the other 3 tires look like?

 

[ripcord]

Has a locating pin on the axle perch sheered off allowing the spring pack to shift forward or back relative to the axle? Also, look for bent and out round wheels, non functional shocks, bad springs or spring bushings, bent or busted spring shackles, etc? You've got something going on for sure.

 

[SwampSurvivor]

How are the wheel bearings? Would that year Dodge have used greased bearings on the rear instead of oil lubed bearings? If it's a full float 60 itll run with bad wheel bearings and not lose all the fluid.

 

[MNgopher]

Did the wear start on the rear or were the tires up front at some point in their life? How are the front tires looking?

 

[JHZR2]

4 wheel alignment will tell you for sure. How many miles on tires at this picture?

I really don’t know. I bought the truck with 436k miles on it, and now it has 439k. I didn’t get A tire receipt, but the po said about 10k miles... so at this point probably between 10-15k miles?

Worn leaf spring bushings or the axle housing is bent/twisted. I would have it put on an alignment machine to see how bad the toe really is, and which way the axle is actually pointing.

You’d need to rotate the tires to see if the wear continues on the others.

Are there full floating hubs on the truck?

All of that is in the cards..

Its a Dana 70 LSD.

Honestly I don’t know how to tell if it is full floating. Here’s the FSM:

 

[ripcord]

Scalloping or cupping is usually caused by worn out shocks, BTW.

 

[ripcord]

With 400K miles on the truck and the uneven tire wear, it's for sure due for some suspension work.

 

[JHZR2]

If the shocks fixed it, the wear won't get better; it just won't get worse.

I’d think the high points woukd wear down faster. Maybe not...

Like mattd said. I would also suspect fatigued springs. Is the frame bent? A bent frame or your axel not being square to the frame could cause this to. Get someone to drive it for you and you follow in another vehicle. If it runs down the road like a bulldog, it darned sure ain’t square. Another thing is your limited slip staying locked up.

No reason to think the frame or axle are bent, it no reason not to either. Old truck with lots of use. Once in a while I think it sits lower on the right side, but it’s always parked on a road or someplace with a slope so it’s tough to definitely say.

Good idea to follow behind it.

LSD has fresh fluid and additive.

its not just inner wear, its the worst there, but the tread blocks are worn cupped/scalloped?
ie it looks like someone randomly sanded the tread blocks.

is it possible the front end is starting the wear pattern?.. and you rotated them?
What do the other 3 tires look like?

The two pics are the two rear tires. The two fronts look a lot more evenly worn. I havent rotated the tires...

Has a locating pin on the axle perch sheered off allowing the spring pack to shift forward or back relative to the axle? Also, look for bent and out round wheels, non functional shocks, bad springs or spring bushings, bent or busted spring shackles, etc? You've got something going on for sure.

From what I can tell, everything looks the same on both sides. Shocks before werent great, but are now new. Wheels are fine, and truck rolls down the road smoothly, no wobble or bumpiness. I don’t really know how to verify bad springs or bushings, though I’d suspect at least some rubber is done for...

How are the wheel bearings? Would that year Dodge have used greased bearings on the rear instead of oil lubed bearings? If it's a full float 60 itll run with bad wheel bearings and not lose all the fluid.

It’s a 70LSD, picture above...

 

[mk378]

That is a floating design. The hub rides on the greased inner and outer bearings, which are put under tension with the adjusting nut just like the wheel bearings of a trailer. Those bearings completely hold up the weight of the truck. The shaft "floats" through the hollow spindle and applies torque to the hub through the flange.

 

[JHZR2]

That is a floating design. The hub rides on the greased inner and outer bearings, which are put under tension with the adjusting nut just like the wheel bearings of a trailer. Those bearings completely hold up the weight of the truck. The shaft "floats" through the hollow spindle and applies torque to the hub through the flange.

So is that something I should re-do? I have set bearings on my MB cars...

 

[ripcord]

If if the bearings were bad enough to cause cupping like that, you should be able to jack the rears up and feel the slop by rocking the tires. They would probably be making plenty of noise, too.

 

[JHZR2]

None of that... I know it’s solid from when I did brake shoes...

 

[mattd]

I really don’t know. I bought the truck with 436k miles on it, and now it has 439k. I didn’t get A tire receipt, but the po said about 10k miles... so at this point probably between 10-15k miles?



All of that is in the cards..

Its a Dana 70 LSD.

Honestly I don’t know how to tell if it is full floating. Here’s the FSM:

View attachment 41348

It does not have full floating hubs. I was getting at a wheel bearing problem but it can’t be that.

 

[Silver]

Measure the distance between the front edge of each tire, then the rear edge, at exactly the same height, to find toe.