No personal experience with the 48RE, but plenty with the 47RE. Nearly all of the problems I have experienced have been computer, transducer, or pressure solenoid related. The fact that yours works for a short period after restarting makes me suspicious of your electronics. Are you getting a "check engine" light? if so, pull the codes and see what they say. There is a website: transpartsusa.com that sells 47/48re parts at good prices, ships from FLA. You might check some of the Dodge Cummins forums for specifics on known 48RE failures. Both the 47 and 48RE's are essentially '61 torqueflights with OD, lockup converter, and an electronic governor/oil pressure regulation system. They should have kept the '70s mechanical governor setup, a lot less to go wrong. Oh yeah, make sure the check valve in the trans cooler line is not plugged. Good Luck.