NP200 Transfer Case Rebuild

[NAM VET]

My TC is back in, and about to add oil, and be back on the road. I have found the pictures and experiences of others invaluable in my truck's restoration. So, though I would post my own saga with a series of pics here. My NP200 slowly leaked more and more, oiling up the brake, and needing at least some added oil, perhaps a half pint every 100+ miles. I read whatever I could about how others replaced the main seals, and Charles T also gave me pointers and cautions. I first thought I would replace the main shaft seals in-truck, then just decided to drop the TC. I put my truck on stands, and then found it was too high for a jack mounted bracket, and too low for an under lift trans jack. So I made a wooden bracket, tall enough to drop and then reinstall, and low enough to slide my bracket under from the rear. Undid all the bolts, and gently lowered my TC, and it started to topple off my wooden stand. But got it down and out without dropping it. Then found I could not get the rear big oil seals out. So after cleaning it, took it up the 100 miles to M37 Rebuild, where Charles completely rebuilt it. New SS shifter shafts, replaced one internal cracked gear, new shims, and a new machined brake drum, as mine had tiny cracks at the bolt holes. All new Viton seals.

Here at the start: More pics to come. NV
[url=https://postimages.org/][img]https ... .jpg[/img][/url]

[NAM VET]

Here, the greasy mess, with years of baked on crud. While it was out, I cleaned all the shafts and painted them. NV
[url=https://postimages.org/][img]https ... .jpg[/img][/url]

[NAM VET]

Here on my wooden bracket. My intention was to install with the rear cross member bolted on. My plan was to raise it up, shove forward to mount the front on the riveted cross member, then jack the rear member up and bolt it in. Easier said than done, had to notch the wood several times, and it was a close side to side where my wooden sides were. I was worried about the TC falling off, so drilled and tapped several bolt holes in my jacks steel plate, then bolted the bottom of my wooden bracket to that, and strapped the TC to the bracket. I did not want to drop steel pins in the front bolt holes, because if it fell off, it would bend the front brace. I used wooden dowels, which would snap off if it fell off. NV
[url=https://postimages.org/][img]https ... .jpg[/img][/url]

[NAM VET]

now to jack up. This was some hours to move it slightly and clear under carriage rods and frames and such. NV
[url=https://postimages.org/][img]https ... .jpg[/img][/url]

[NAM VET]

I found trying to push the TC up and forward on the front crossmember kept shoving the TC almost off my bracket, so used these clamps to hold it to the rear of my wooden bracket. NV
[url=https://postimages.org/][img]https ... .jpg[/img][/url]

[NAM VET]

If just the seals had been replaced, this broken tooth and cracked gear would have eventually caused big problems. Charles T had another good one he installed. I used Blue Loctite on all fasteners. And I ordered from Jegs racing reduced head nuts for re-attaching the drive shafts and output yoke shafts. The smaller ones are 5/8 wrenching, a lot easier to wrench than much larger nuts. It was a lot easier to use a 5/8 flex socket too to bolt them up. More Loctite here too. Charles suggest I use a 50 wt Amsoil synthetic heavy truck transmission oil, looked it up, sounds good for gears in the TC. It should be here this PM. New brake band. I removed the shifter rods, and cleaned the threads on the clevis attatachements and the rods, so I could adjust much easier.

It was a two month and exhausting project for me. Many thanks to Charles for both his suggestions and then doing a complete rebuild. NV
[url=https://postimages.org/][img]https ... .jpg[/img][/url]

[NAM VET]

Oh, just to add that all bearings and races were replace too. NV

[Cal_Gary]

Outstanding replay Nam Vet! Thanks for the photos too-brought back some memories when I changed mine out.
Gary

[sturmtyger380]

These are heavy suckers! Great Job!

[PoW]

the hardest part to find whilst doing a through TC rebuild is the loose rollers used. they don't seem to have come in the rebuild kits.

DG

[NAM VET]

We were for awhile, so finally adjusted the two shifter rods perfectly. I was not able to move the short new SS TC shifter rods in and out with my hand, per the TM, but following the instructions to position the rods with their threaded clevis pins and cottons and drilled bolts at the front by the transmission, they both now click into their detents for both shifter handles and rods. Makes it a lot easier to clean the threads on the rods and the clevis before being underneath the truck. I am driving the 200+ plus miles down to Charleston soon, will be there for a couple of weeks. Test drive this am shows no leaks on the Charles T rebuild, and easily shifts in and out of four wheel and hi and low ranges. And does't pop out of any lever positions. Stay health, NV in UpState SC

[Cal_Gary]

Thanks Hal, let us know how it does on the trip!
Gary