Re: E4OD/4R100 Gurus - diagnose

I'll take a shot at recommending a solution since I encountered a simular situation with my 97 F250 Power Stroke diesel. Your transmission is an E4OD. In the front pump, I replaced the line to lub pressure regulator valve with Sonnax 36424-04K. When this valve wears, it restricts cooler oil flow and also raises line pressure which could cause a hard Park/Neutral to 1/2 engagement. If you're going to replace this valve, also replace the front lub drainback valve with a meltproof aluminum one (Sonnax 36425-01K). The OEM is made of plastic and will melt at high transmission temperatures.