Ok so i put my truck up on a hoist the otherday to change my axle fluids and i discovered they my NP-231 transfer case is leaking fluids, this is coming out of the rear gasket that drives the rear axle, is this serious, hard to change any help at all is greatly appreciated.

 

Not hard at all to change. If you really want to do a good job, pull the case and replace all your seals and bearings (rebuild kits are about $100). I did a complete rebuild in about 2 hours.
If you are really set on just changing out that one seal:
1) drain t-case
2) pull rear shaft
3) remove the rear tailshaft housing (4 bolts)
4) replace that seal
5) reassemble
--should take about 30 min. Seal will be about $10. But like I said, if your seals are starting to go bad, you will end up having another leak shortly (but in a different place).

 

thanks for the advice man, im not to confident about changing all of the seals, i only noticed it because i went to go change the oil in it, and went WTF