By main you mean the line pressure tap. I need to go back and recheck my numbers but I think the line pressure falls to near 50 and the forward pressure falls to 0 and then when it engages it comes back to 60. Also when driving down the road in 4th gear around 55-60mph and let of the gas it bucks and engine brakes like its going into 3rd gear. I have my scan tool hooked up and the PCM is commanding 4th, but it being an 04 I can look at the Trans_Rat PID to see what the actual ratio is, but when it acts up the RPMs will raise and the car slows due to engine braking.
This is my theroy on the engine braking. We took it apart and the O/D band was destroyed and the reverse drum was scored bad, replaced both parts and installed a SONNAX servo pin b/c we thought it has to do with a worn case bore, BUT what I think is somehow the transmission is appling the FWD clutch, direct clutch and O/D band all at once and the O/D band is the weakest link. All help is welcomed. I have had reports of cracked cases to bad PCM's and RF interfernce from a bad alternator. This car is running me in circles. THANKS!!!!!