Rear dif oil condition

[DGamelin]

I just drained the rear diff. The oil looked like black metallic paint. The truck has 47k miles and allot of metal files in the oil. Has anyone seen what looks like allot of metal?

It has a limited slip.



04. 5 cc 4x4 dully 6speed 373 47k

93 xc 2wd auto 354 250k

 

[dseabaugh]

I've got a late model 1 ton rear I picked up for the disk brake setup and the gears in the rearend are SEVERELY worn and cupped. never saw a ring gear with teeth worn in a cupped out shape before. this one has lots of shiney oil. My guess is someone put regular gear oil in it. The only time I let the ******** change my oil they put regular gear lube in the differential and when I checked it a year later it was black as the engine oil... . burned up. I changed it to synthetic and the oil has stayed clear like new for 7 years. Lucked out no damage. Just fried cheap ******** oil. After the ******* oil I pulled the hubs and everything and checked them. luckily I had only put about 9,000 miles on it that year. If I had put on a lot of heavy loaded miles it probably would have looked like aluminum barn roof paint when I drained it. I almost think the later model trucks have softer gears. JMO.

 

[DGamelin]

The ring and pinion look good, I think it came from the inside the carrier. I bought the truck used, the lube didnt look like synthetic. On the right end of the carrier you can see the inner gears wearing on the carrier where they stick out of the little slots on the right end, it had burrs hanging from slots. You can feel the posi on dry asphalt and when you need it in deep snow it is useless. I am a little disappointed in the amount of repairs this truck needs at 47k. Front and rear u-joints, front pinion seal, looks like the rear engine main seal is leaking, rear diff oil looks like mud. finding u-joints wasnt no fun. The spicer are about 10thousands to big we wound up takeing 4thousands off each clip. This is the first AAM axle we have had in the shop.

 

[MA2LA]

Most people don't change the oil in the rear when they should. with the first change should be at about 15k if you do any real towing.