I'm finally ready to change the rear diff fluid, and have decided to go with Amsoil. How many quarts does it hold? Do I need a special additive for the limited slip?

 

For a Dana 70, 6.5 pints. For a Dana 80, 6.3 pints. Amsoil says you shouldn't need the modifier. Some people still need it, others don't. Depends on the clutches in your limited slip unit.

 

I would go to Dodge and get the Mopar additive it is cheap and you only need 2 of them.

 

If you are going to use a synthetic, I would use caution on adding the friction modifier.

Here is a suggestion: Install your new fluid. Go for a test drive, turning some tight figure eights, listening to the rearend. If you hear it grabbing, add friction modifier 2 ounces at a time. Test again. Continue til you have a quiet rearend.

If you add too much, your limited slip will slip all the time! Then you will have to drain the fluid and start over.

 

[quote author=cstmfabman link=board=4;threadid=19427;start=0#msg182336 date=1063085129]
I'm finally ready to change the rear diff fluid, and have decided to go with Amsoil. How many quarts does it hold? Do I need a special additive for the limited slip?
[/quote]

I'm not sure how many quarts you need, but usually you don't need to use the friction modifier with the Amsoil product.

http://www.amsoil.com/products/tgo.htm

If you do feel that you need to use a limited slip product, Amsoil just came out with a new product called Slip Lock that can be added to any gear lube to eliminate chatter. It comes in 4 oz bottles and treats differential with 2 to 4 quarts.

 

The Dana 80 on a 2 wheel drive may hold upwards of 9 pints.