I got my G a few months ago, and have slowly been bringing it back up to a decent stock level of cleanliness/drivability, ect. One of the main thing that SUCKED was the really harsh shifting transmission. The guy the works on my cars (I can do a lot myself, but I work 55 hours a week, and just don't have time) told me to add about a half a bottle (4 oz) of GM limited-slip additive (Part # 1052358) to the transmission. I finally did this about a month ago, and have driven a few hundred miles. I can now report that it fixed the problem. Shifting is now very smooth, and improved the overall driveablility of the car tenfold. My next question, do the transmission and differential share fluid? Or does the diff have a separate fluid reseviour?