Here is one for you. I have a 99 Ram and I do know there should be TF4 in the transfer case, but after I had a center pin break in the rear lift spring this past week I found gear oil coming from the tail shaft of the transfer case. It also seems the seals on the transfer case are leaking as well. What should I put back into the transfer case

 

I would flush it out REALLY well, then refill with ATF +4....

 

Not really a big deal actually. ATF+4 is only required so that when tranny/tcase seals fail and they swap fluids there isn't supposed to be immediate catastrophic failure. No clutches or friction surfaces in the Tcase to be picky. If it's thick and slick, the Tcase don't mind.