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.

 

Wow, which dealer was that? Those are rip off prices!