So I'm about to service my t-case. It has a slow leak from the pan gasket and both output shaft seals.
Being that I don't have a service manual (yet), the forums are my go-to!

Here's what I'm going to do:
Pull fill plug.
Pull drain plug.
Drain fluid (looks like ATF leaking out! wtf was the last service guy thinking? )
Pull t-case pan.
Clean mating surfaces, inspect for wear, damage.
Fit new t-case gasket (I'm foregoing rtv... is that okay?)
Replace t-case pan, torque all bolts to 25nm (?)
Replace drain plug with new copper washer, torque to... ?
Add a bottle of white shepherd.
Refill with valvoline DuraBlend gear oil.
Replace fill plug, torque to...?

And that's it!

 

No need to torque things, just good and snug.
And def ATF was the wrong thing to put in there, Jeeps, Chevys and Fords use ATF in their t-cases.
Real trucks use gear lube.

 

There is an inspection window so no need to pull the whole sump off if you don't want. Also you only need 1/3 bottle of white shepards in a gear box of that capacity.

 

Drain and fill, but I would try the White Shepherd before you went to all of the trouble of changing the seals, that is what the White Shepherd is for. All you are out is the cost of some gear lube if it doesn't work. Phil

 

I didn't touch the seals, just pulled off the pan and replaced the leaky rtv gasket with a proper LR paper gasket.