8 3/4" Gear Oil Level

There is a plug on the side of the case. Fill it up until the fluid starts coming out of the hole which would indicate that it is full and then put the plug back in and tighten it down. Your Pinion seal is probably leaking. YES there is a Friction Modifier that comes in 4oz doses Mopar Performance makes some. You need 1 of them and about 2 1/2 pints of 85/140 Gear oil if it is drained dry to start with. Some guys use the lighter synthetic stuff but I dont.