My '97 Factory Service Manual says to use Dexron II or ATF Plus. Obviously this must have been before the later Dexron's and ATF+'s. The '01 FSM says to use ATF+4.

My '97 FSM says 80W-90 GL5, but the '01 FSM says you can use 75W-140 if heavy duty use is in order. I'm guessing I should probably stick with the 80W-90 since I live in Northern Utah and it gets cold in the winter.

What are you folks using?

 

look into redline products...i use it, great stuff.
http://www.redlineoil.com/Products.aspx?pcid=4
i think it gets as cold here (elevation 7200 feet)

 

Your rambling has everyone confused.
NP241 uses automatic transmission fluid. It really don't care if ATF+4,+3, dexron 3 or 6. It will all work.
The differentrials can use 75-90 or 80-90 in GL 5 formula. If you pull loads or heavy service you can go to 75--140 and synthetic if you like. The syn oil is what factory calls thermally stable for HD use.

 

Yeah, what dozer12216 says. My FSM says ATF+4 for the transfer case and I just drained it and put in dexronII. A synthetic 75W90 or something similar will work in the diffs. Most synthetics don't need any LSD additive so that's a plus....

 

I you need any help just yell, I'm not that far.

 

Got it. I figured that since the transfer case was made up of gears and a chain, with no friction materials, that it wasn't necessary to use ATF+4. Thanks.

 

Here's some good info.
http://www.allpar.com/mopar/transmissions/fluids.html

 

That's a pretty interesting article. Although the NP241 only uses about 2 1/2 quarts therefore not too expensive to use, I can't see it would be much of a benefit for the ATF+4. It's just an open oil bath lubrication system. Not too many close tolerances in a transfer case.

 

ATF+4 is a synthetic fluid, and it would be a benefit because there is so little fluid in the transfer case, it has little to no way to shed heat, and by shear volume its being overworked. TC oil is like the powersteering, lots demanded from it, yet its fluid is seldom changed