i'm sitting here trying to figure out the viability of doing it myself. i haven't bought the atsg book yet, i'm simply looking at the service bulletin from bmw and a transtech monthly bulletin that addresses issues in doing those transmissions. also, i have the 100 page pdf/foldout from gm hydramatic/powertrain, but that only addresses the operation, and not disassembly--it is a great thing to have around, though. if any of you have ever rebuilt a transmission and would like to tell me the viability of doing this, i'd appreciate it. the step-by-step from bmw about this gasket is located here

http://plaza.ufl.edu/rroopnar/attachment%5b1%5d.pdf

my concern isn't the amount of effort it would take to do this, but whether or not i would require the special tools described therein. the biggest hurdle i see is getting a fixture to compress the spring plate without f'ing it up, but i wonder if regular tools would work for the rest of the procedure. this transmission had the overdrive slapped onto it, and the gasket in question is where the overdrive joins the rest of the unit. 2 valve bodies are involved, iirc. a big thanks in advance.