A Truck question

I own a Dodge Mega cab with a limited slip rear end. The limited slip started grabbing a little about the time it said in the owners book for a fluid change. Changed the fluid and added 2 bottles of the limited slip additive. To make a long story short it is still grabbing from time to time. Not bad but you can feel it.
Should I add a 3rd bottle of fluid and see if it stops it completely.

Ronnie