Atf 3

 

The easiest way for me to do mine is to drop the skid plate. I put a bottle jack on the oil pan and take the pressure off, then unbolt the trans mount and the 6 skid plate bolts.

Then you can get a drain pan in there instead of the oil from the trans running all over the inside of the skid.

The trans takes 75W80 gear oil, however some use 10-30 motor oil and others use synchromesh, or full synthetic.

The T-case uses ATF-3 or the equivalent. I have Royal purple synthetic in both the trans and T-case in mine. Makes for much smoother shifts but it is expensive at about 4 times the cost of using conventional oil.

 

This is a big discussion because the fluid was originally 75W-90 GL5 gear oil. Since then, it has been found that GL5 lubricants are tough on yellow metals, such as brass syncros.

Here is the sum of what I have found: use 10W-30 FULL SYNTHETIC motor oil (Mobil 1, Royal Purple, Castrol, Valvoline, Pennzoil, Lucas, AMSOIL, or any good brand), or use GL3 gear oil. Redline is very popular and so is synchromesh. Basically, you should choose between GL3 and 10W-30. No GL5 or ATF.

Now, the most convincing argument I've heard is for the 10W-30 motor oil, and apparently the Mopar part number listed for the old fluid now directs you to motor oil. I haven't looked into this, but it sounds interesting. I personally use motor oil, it's easy and cheap. Plus gear oil and axle grease are some of the worst smelling things, especially because they stay on your hands for a solid day.

As for the transfer case, I use the Castrol ATF +4 for Chrysler vehicles. At least that's what I put in my power steering, I will do the transfer case fluid next year. Haynes manual says ATF +4.

 

The transfer case if not real picky, but you can't go wrong with ATF+4.

Synthetic 10W-30 or Redline MT-90 work well in the transmission.