Common

I'm changing the fluid tomorrow, what type of fluid do I need and how much of it?

Thanks!

Fueling around

http://www.dodgeram.org/tech/specs/a...RBI_specs.html

Lube grade & brand is wide open. You'll need something with friction modifier to quiet your limited slip.

Dartmouth 12V

Unless you are towing really heavy in hot weather, I would suggest a synthetic 75w90 oil. If you are going to be towing heavy and don't see really cold weather, you could look at 75w140. As far as brand goes, that is your choice.

46mech

80w90 didn't cut it for my LSD; didn't matter that I put the friction modifier in it, it still chattered real bad. It was recommended to me a long time ago to use 80w140 so that's what I've used ever since..... still use friction modifier with it.

WyomingDennis

I just did the fluid replacement on a 98, Dana 80 LS with Mobil One 75W-90. Ten pints is the correct amount but don't believe Mobil that you don't need a friction modifier, my truck chattered terribly in turns. I siphoned out 10 oz of gear lube and replaced it with 10 oz of Mopar friction modifier, the chattering went away immediately.

Fueling around

That was a lot of friction modifier to add in 1 gulp.
Recommended method is to add about 4 ounces at a time. Drive the truck including lots of figure 8s to allow the modifier time to get into the clutch material. If the LSD chatters add more and repeat.

stock600

I do know you want to use at least the correct amount of FM, because in my 99 with the D80 it didnt work as well without it. I to used 75/140 from O'Riellys. My 04.5 doesnt require the FM as it is a mech. posi and works so much better than my 99's.

WyomingDennis

10 oz. is the Dodge recommendation for that dana 80. I added it all at once and it seems to work fine.

frankv

do regular auto parts stores sell the friction modifier, i am getting ready to change mine this weekend

46mech

Yep, just about any parts house will have the friction modifier. Just tell 'em you're looking for the LSD friction modifier. It's been a while since I did mine, the modifier may not be specifically state it's for LSD's, but should at least include them so don't let that hinder you.