Transfer case swap question

[JeffsJeep04]

My 208 seems like it's on the way out. I'm guessing worn shift fork pads are the root of the issue based on past experience, but regardless, it has developed a whine in 4x4. Happens whether the hubs are locked in or not. I started searching around for a replacement and managed to score an NP241 from an 89 suburban Plan is to roll with the 208 as long as possible because...well, it's cold out!

Anyway, I got the case with the adaptor and I'm trying to figure out what the best way to tackle this is going to be. I've always been a manual transmission guy, so this auto stuff is still new. I'd like to pull the case off in a way that will avoid loosing any fluid from the transmission if possible, but I'm open to ideas from those who have done this before. Am I better off unbolting the adaptor from the t-case and keeping the current adaptor in the blazer, or should I save myself two bolts and pull the 208 with the adaptor attached?

 

[496truck]

I've done the t-case change out too many times lately...
Get yourself a large by huge piece of cardboard to lay under the truck. Easy to slide around on under the truck and easy to wipe up any drips from loose fluid before they soak into the driveway. Seriously, it was way easier than a creeper.

jack up the rear of the truck, as high as possible and put it on stands. this tilts the assembly forward to minimize trans leakout.
drain t-case
remove front and rear d-shafts
put a jack under the trans pan, use blocks of wood to distribute load
unbolt and remove trans x-member
remove t-case mount, good time to replace it if needed
lower trans/t-case a few inches for better access
remove speedo cable, shift linkage and the 2 bolts for the support bar
unplug 4wd switch at the top of the case
put the drain pan under the t-case to adapter area
remove the 6 bolts that go from the adapter to t-case and a bit of fluid will come out, not a whole lot
lay under the t-case and get ready to bench press that biotch out of there
slide it off the back of the trans, let it down on to your chest and roll it on to the floor

Clean up the mating surfaces of the adapter and t-case before the new one goes in and use some good ol' black RTV to seal it up.
bench press the new t-case up onto the splines and it will support the case while you line up the first bolt
get that first bolt in and the rest is cake.

 

[JeffsJeep04]

So the 6 bolts are pretty accessable? I know on my jeeps the top two were always a huge PITA to get to. Is the seal between the trans and tcase between the adaptor and the tcase (at the rear of the adaptor)?

 

[496truck]

The input shaft on the t-case has a seal to keep trans fluid and t-case fluid from mingling. The adapter is open to trans fluid, no output shaft seal. Technically there is a gasket that goes between the t-case and adapter to keep trans fluid from leaking out between the 2, but you can seal it up with black RTV if you don't have a gasket. Personally, I prefer the RTV over the gasket.

The top 2 bolts are easy once you lower the trans down a little bit on the jack. I used a ratcheting wrench. Take out the top 2 first and work your way down to the bottom. Leave the easiest one for last. When you remove that last bolt don't be surprised if the t-case rotates down a little because it's heavy on one side, just be ready for it.