FOR INFO:
Some misinformation on this thread needs addressing.
These transmissions & transfers can definitely be re-built & not leak.
Any bolt that goes to oil must be sealed & the thread must be perfectly clean in/on both parts.
Sealant is used on gaskets as you don't intend to be doing the job again.
There are different types of bearings used in these transmissions:
(a) fully sealed
(b) fully shielded
(c) 1/2 shielded
The shielded ones are NOT sealed & a totally different animal.
Use fully sealed bearings & following the advice below, may help.
1. Sealed bearings are sealed for life & ripping out half the seal ruins that aspect as the proper hi-tech lubricant sealed in is diluted/contaminated by external inferior oil.
What do we think are on most cars/semi hubs today?
They're sealed for life & will do 100000 up to 1,000,000 miles
So no-one on this Forum is ever going to have to worry
2. Bearing outer to case clearance should be sealed.
3. This sealing is pointless if the bearing is not held in place securely by the bearing retainer as intended ~ if the bearing can move back & forward oil will be pumped. Gasket thickness or even skimming the retainer is a solution to ensure the bearing is clamped tightly
4. The original circlip on the input bearing was generally thicker section than the replacement ones & that can alter things going on in 3.
5. The oil return hole in the transmission case needs to be sealed if the rest is done properly.
6. The output bearing [I always use sealed] should not move in the cavity between the transmission & transfer, case as it will also pump oil.
7. Shims in front of or rearward of the bearing will be necessary to eliminate movement [if there is any] of the bearing outer.
8. Gasket thickness is critical BUT all must be calculated into the correct positioning/adjustment of the mainshaft, as is sealing in the housing.
Why some of use use dummy bearings for setup
Folk who live in the past are often not purists. They don't know any better, refuse to learn & have not kept up with progress.
Often they don't help but hinder.
There are many fabulous solutions to many problems we had back in the 50's & 60's.
Locktite for example.
I would not be wanting to go to a '60's trained surgeon who loved cutting, but knew nothing about micro-surgery or kept learning, working on me, that's for sure.