[hatzie]

Originally Posted by kljfamily

Hello,

Just picked up a 2003 8.1 2500 with about 170k. Everything was fine until I drove it on the freeway and the t-case (gm 246) started grinding and blew. Found it the pump had rubbed through the case (know I know common problem).

Not a novice, so I tore into the t-case. Turns out the planetary gear exploded in there so I have a lot of shrapnel.

A friend has a 2002 t-case I can have for parts on the cheap. Since i just bought this thing I don't have a lot of extra cash.

I see on researching that there was a change in the np246 in 2003. So question is will the 2002 np246 work on my 03? (I think the change had to do with the push button 4x4 but I could be wrong) or at least are they similar enough I can rob parts from it especially that planetary gear which is a costly part. Then I could buy a general rebuild kit and bottom half since it has a hole in it.

My only other option is to go to u-pull it this weekend and see if I can manage to pull out a t-case in the middle of the desert here in Albuquerque.

thanks

Kris

I don't see why not. It should bolt up mechanically as long as the spline count is correct.
If the shift motor is different you can probably swap the shift motor from your burnt xfer case. Any switches the same way.

Originally Posted by OldCreek

I can't really help you directly but this link may be of help:

https://www.merchant-automotive.com/t-gastruck.aspx

I think you can get the parts schematics and compare..


Also, I wanted to thank you for posting this. I just bought a 2003 8.1/Allison 1000/NP263XHD with 185k miles. I didn't know about the pump rub issue and researched it. I went out to my truck and found a pinhole and wet transfer case...
looks like another weekend day soon to be occupied! But, that's better than a grenaded case and being left on the side of the road.

Best of luck!

Wil

If you already have a leak you'll need to replace the rear case half. It's common enough that there are aftermarket replacements.
Worst case you have to swap a bnch of bearings along with the pump repair.
Make sure to get the o-ring for the pump pickup tube. It doesn't come in the kit.
I always clean off and put the magnet back in the pickup screen area even tho some folks say not to.

Look at the South Main Auto re-assembly video for the GM NV261. Eric does a pretty good job of explaining how to put one back together. The 261 & 263 are pretty similar.