the reason I ask is I'm reading up on changing the rear diff fluid on my 2005 Ram 1500, I understand the process, but not sure, on the anti -slip and what the correct fluid is, and do I need the additive

also should you change the gasket or use the old one

thanks

If unsure your Local Mopar Parts (dealer) guy can look up your vin and tell you exactly what you need. Your owners manual will list what you need as well. There should be a sticker on inside of your glove box that tells what diff you have to tee up with your book.

Sorry never heard the term anti-slip used with the 9 1/4 rearend but if you have an LSD (with 3.92 gearing I assume) I would say there is a "friction Modifier" type additive for sure and you want to buy the right fluid which i believe is 75w140 synthetic.

About the gasket there probably isn't one as most just use the Mopar Gear RTV on its own and I beleive thats how they come from the factory. Personnally i make my own gaskets using thin fel-pro cork and am assured no leakage.

Yes, they are the same thing. L.S.D. (Limited-Slip Differential) is the generic term for a differential having a basic traction-aid. Anti-Spin, is Chrysler's name for their limited-slip differential.

LSD=Posi=Anti-spin

thanks for the quick replies, all it says on the door sticker ( not one inside the glove ) was anti-slip Diff and it says 3.55 Axle ratio, is that what is referred to as the rear end gears ??

is 3 quarts of 75z-140 fluid correct and enough ??

If it's an LSD you must add the additive - mine held a bit over 2quarts with the additive. Synthetic Mobile 1 - 75-140.