I went to check diff lube, stuck my finger in and the lube is not the honey color it should be. Removed cover is very brown looking and also notice the you can see the side gears through the end of the diff housing. What's causing the side gears to wear into the diff housing. Can this be repaired or do I need a whole new rearend. I will try and post a picture when I get one.

 

That side gear wearing is actually oil flow ports machined into the carrier on the new trucks. Although they look like and feel like they wearing from the parts.

 

Ahh, thank you. This all started a couple weeks ago, after a run on the highway the truck will make a strange growling noise when first starting out in 1st or 2nd, but you can drive it around town all day and it will not do it, do a 30 mile drive on the highway and stop and take off from 1st or 2nd and then it is seems to do it more if you are turning. Thats why when I noticed the dirty rearend fluid I popped the cover and seen the gears through the housing and I didint remember seeing them last time I changed the fluid but must have.