Sorry, to hear the B2 piston was not the problem. If I could give my .02 worth. If you decide to fix the transmission...don't take it to anyone other than a shop that specializes in MBZ transmissions. That is if you don't do the repairs yourself. I learned the hard way. I put confidence in a brand name shop, and I ended up R&Ring that transmission 3 different times. I was in a quandry for over a year with them. Finally, I heard about a MBZ only shop, and contacted them to do the repairs. They dyno test them before they leave the shop, and when I got it back in was like a dream. The original transmission shop ended up refunding my monies, but it didn't pay for all the lost time and other money.