Pulling off the Perfect NP246 Transfer Case Rebuild

[rockola1971]

I've been staring at my core. The tcase I bought to use while I was rebuilding mine. It's been sitting completely disassembled on my bench since I finished this project. I think it's time to clean up my garage and get parted out, or rebuilt and sold. The one thing that held me back from before...

The original clutch pack spacer was all chewed up. I think somebody maybe tore it down before and didn't spec spacer correctly. I'm not sure how to spec one w/o measuring the old one or that stupid expensive factory tool. Any tips would be appreciated.

Here's a good vid and the guy shows GM spec pages too.

(There is a part 1 and 2 video) Im working on piecing together a J44295 kit together so I can get the measurements and then anyone can build their own test fixture up at home. The circular weight weighs 10lb so GM specs a 10lb preload on clutch pack before measuring play.

 

[Matthew Jeschke]

Yeah I watched that video when I built mine. He's using the tool, I need to figure how how to do it without the tool.

The last one I did I just measured the old clutch pack and made sure new one was same thickness (or really close).

On this one I suspect the clutch pack is wrong as the spacer is all chewed up.

 

[rockola1971]

Yeah I watched that video when I built mine. He's using the tool, I need to figure how how to do it without the tool.

The last one I did I just measured the old clutch pack and made sure new one was same thickness (or really close).

On this one I suspect the clutch pack is wrong as the spacer is all chewed up.

No way to short cut with chewed up shim. Once I get the J kit pieced together I will post up the measurements so anyone can make their own jig up.

 

[Matthew Jeschke]

Oh awesome thanks!

 

[rockola1971]

Oh awesome thanks!

Looks like someone already did it for me. He is the man!

You can make the weight out of anything you want as long as its the right spec height. You can add weight to it from above to achieve 10lbs.

 

[Matthew Jeschke]

Nice! Now to rig something up like that. I might have to have a machine shop do that for me.

Do you know what kind of paint will stick to these magnesium cases? Mine is corroded really bad.

 

[Matthew Jeschke]

Looks like someone already did it for me. He is the man!

You can make the weight out of anything you want as long as its the right spec height. You can add weight to it from above to achieve 10lbs.

Did you have a machine shop make you one? If you do can you let me know, I may just order one from them too. My closets machine shop is in Tucson and I kind of avoid that place but if I get up there I'll let you know and see what they want to make you one too.

 

[rockola1971]

Did you have a machine shop make you one? If you do can you let me know, I may just order one from them too. My closets machine shop is in Tucson and I kind of avoid that place but if I get up there I'll let you know and see what they want to make you one too.

Ive got an original base already. Been looking for the other 2 pieces broken up from a kit so I can land them cheap. Then I might have to look into a way to get past any copyright if you know what I mean.

 

[Roadstar01]

You dont need a special tool. All you need is a caliper to measure your clutch stack and compare to specs. Measure your old stack for comparison.

But you can't compare the old clutch pack height because the material has been worn off the clutches. I wish I could find what the special tool height is and then I know what to Mike at with the tolerance is can you help with what that is or anybody who has the special tool?

 

[Matthew Jeschke]

Material worn of is minimal. Less than even rounding error would be. Unless you have a badly worn transfer case in which case a visual inspection would show burnt clutches, cooked steels, and other problems. I tore down a second txcase to rebuild and had issues which precluded me from using the comparison method to spec clutches.