If you're going to follow the tsb why don't you just get the torsion really warmed up and drain n fill then road test it....you might only need one drain. You will barely get a litre in there when you fill.
If one drain n fill doesn't do anything 2 or 3 probably won't either.

 

Your gaskets will be much cheaper I think.. the 90430 ones.

I'm not sure now which number was for the transfer case...

 

Just get Redline fluids, same or better quality and far less expensive.