After draining out all the type F thinking that is why my tranny was acting the way it was an putting Dexron III back in , it was still the same. Meaning the convertor was going crazy it was short shifting an missing gears. We were down to a stretched TV cable or the TCC switch. An after adjusting the TV valve per GM recomendations time an time over we finally just unplugged the TCC on the driver side an the darn thing shifted like always. So I must think this was it all along. To my understanding this is the main switch used to lock the convertor so now I just got to find out where i can get one!!!