I recently had my Auto Trans Services (about 5k ago) and my trans has a minor surge going from 25-30mph of about 250-400 RPMs. It is a slip but if you feather the throttle it isn't there. I thought I might try some auto rx in the trans but don't want to shell out another $130 to get the trans re-serviced. Would it hurt anything to keep the auto RX in there for 10-15k?