My buddy has an 06 2500hd with an 8.1l, and the allison, and when he puts it in 4x4 something in the driveline feel like it it slipping. Almost feels like the chain is slipping a tooth in the transfer case. Can the chain stretch enough to slip on the gears, or could it be something in the front diff?

 

Yes the chain can stretch enough to slip. I have experienced it firsthand. Its very loud and echoes through the driveshafts.

 

That sounds about right, it is a really loud clanking sound. When it does it, it happens a couple of times real quick.

 

This ended up being the little wear clip, broke, and it wore a small hole in the case. The lack of fluid wore the shifter fork, so that it won't hold it in 4x4. He ordered a replacement fork, but how do we plug the hole?

Can the hole be jbwelded, or does it need to be welded over?

 

You can use jb just make sure its real clean when you do it..

 

He took it to work and put one half of the case in their parts washer and left it on all day, then switched sides today. When the parts come in we will use 1/2 a can of carb cleaner, hit it with a sanding disc, then use the other 1/2 of the can to finish cleaning it.

He also ordered a new chain, and the revised wear clip. It's crazy that it ate half of the fork away, but didn't harm anything else at all.

 

Very odd that it only screwed up the fork, but lucky if that is all. That pump wear clip is such a bummer that they all fail, just be sure that the clip sits all the way in the case half when you put it in. Also be sure to flush out the pump pickup tube and screen.