Well, I guess it was bound to happen. Everything worked great with my differential swap... until I looked at my rear passengers tire. The tread blocks were wearing funny, they were angled up at the back. The drivers side was ok though. The axle shafts don't look bent and the truck drives ok, except for an occasional wander when i let out of the accelerator. Pulled drain plug and there was sludge on the plug... does it look normal?

 

Don't know about the tire, subscribing though but my plug looked like that also when i changed my rear fluid with R.P.. Pulled my drain plug again and i had some very small shavings like in your pic. I hope its just whats left over from the old fluid. Subscribing to this too..Bump

 

When you did your swap did you take the cover off to inspect the guts? Did you do a gear oil change?

I can't say that I have seen sludge on my plug diff plug.

 

Everything on the inside looked good. The gasket surfaces had some rust. I cleaned it off and re sealed 'er up. There was a very faint 'shadow' of what the pinion would have left if it had scored the differential. This wiped off though, may have been the lighting. The wear patterns on the gears looked great. The diff oil was yellow/reddish colored but smelled ok. There is valvoline 75 140 synthetic in now, but no friction modifier... It locks up really well right now with no chatter



kalsc on a side note, did you get my pm? I have the hub part sitting on my kitchen counter...

 

My newest set of toyos started to do that scrubbing stuff when i bought them. It ended up bieng towed out up front too far. These trucks especially lifted with larger tires are a bear sometimes to get aligned. If you have a shop locally that can do a tractor trailer or a dump truck take it their and have them toe it in im pretty sure thats it.

 

Good question. What rear end ratio did you put in? It's possible to have some initial wear with the new gears, but it's something I would keep an eye on. As for the tire, unless you have a LS unit that is installed backward from the traditional units, I'd start checking out your right rear shock. A bad shock can cause uneven wear in the tire. I learned this lesson the hard way with a new, bad shock.

 

I dont understand whats wrong with the tires? They look normal - im probably just overlooking somethng

EDIT - forget that statement

 

My bad.. the tires on the back? Ya unless its "dog leggin" down the road, its most likely a shock problem. The shock keeps the tire on the road, once it loses its compression the tire hops and creates the scrubbing.

 

Well, the whole axle was replaced from another truck. It saved me a lot of money, until I found the funny tire wear... now I'm beginning to wonder what it helped with...
Yeah, just the back passengers tire is lifting it's blocks. I don't think its dog legging, although i'm never following it. What would cause the occasional wander to the right when i downshift and let off the throttle?

 

Bent axle housing.

When my truck was hit the axle got bent on the passenger side. I straightened the axle, however, it also crushed the bearing surface on the spindle which caused the inner bearing race on the outside bearing to move around. The truck exibited the same tire wearing pulling symptoms you describe. The wandering is because the power and traction is shifting from one side to the other.

What you are showing on your tire is definitely toe alignment wear, where the tire is pointing too far inwards or outwards. Since it is only on one side the axle must be bent, or otherwise damaged on that side.

I found this two ways. I used a laser pointer to check the rear tire alignment to the front of the truck. By just hitting the front and rear edge of the tire I could see that the passenger side tire was pointed inwards. Then I pushed the front bumper up against a pole (i beam sunk into the ground) and when i pushed into it I could see the rear tire actually moving on the end of the axle.

You can check the axle straightness front to rear by placing a mark in the middle of the tire tread on the surface facing forward on both tires. It doesn't have to be exact. Measure between the marks with a tape measure, making sure the tape is straight across, not hitting the springs etc. Roll the truck striaght forward until the marks are facing backwards and take the measurement again. Anything more than 1/4 inch and you will definitely see abnormal wear.

 

Well I must be having no luck at all. I measured the axle and can't believe that I didn't notice it was bent this bad. Measurements behind axle are 6ft 1.5" and front of axle are 5ft 11 5/8". Well there goes nearly $800. What are my options now?

 

You can straighten it if you have a full sized acetylene torch and a rose bud tip. It's difficult for me to explain how to do it, so if you have access to the tools, I'd be more than happy to talk to you on the phone about how to do it. I was able to succesfully straighten mine to within 1/16" at the tires. Unfortunately the spindle was crushed like I mentioned so it wasn't usable anyway.

You need to try and identify about where the bend is. Then you heat the long side in a spot until it it cherry red. This will cause that side to shrink and pull the axle back, effectively shrinking where it was heated. It works because the metal molecules are stretched when it is bent. Heating in a spot causes it to expand and compress the molecules tighter. When it cools, the material shrinks and pulls the area together.

 

Unfortunately I no longer have access to a full sized oxy acetylene torch... I do have access to Mig welders, but those are wire feed and wouldn't help... Did you just heat it then cool it, then heat and cool? Let it heat cycle, or did you just heat it until you think its good? I guess i'm going to have to find a shop who does axle repair... I don't have to trash the axle do I? The wheel bearings looked good still as well as the spindles. Thanks for the offer for over the phone help though...

 

No, you don't have to trash the axle. It will burn the oil off the inside of the tube, so it is best to drain it.

It's not a matter of heat cycling. I heated it up and measured before and after to get an idea of how much area i had to heat to get a certain amount of movement. You can get quite a bit of movement out of it eventually, but there is a limit to it each time it's heated, as well as how much a certain spot will move at all. Mine was off 3/4" inch to begin with and only heated a couple of spots a few times to get that movement.

 

Mr aldridgec deserves "Rep Points". Good advice!!!