i have a 1999 sport with 4.0 pushrod..5r55e...160k...my transmission a couple months ago under heavy throttle on a freeway onramp dropped into neutral between 3rd and 4th...ever since it kept on doing it....ive got so many projects in the garage i had to take it to a mechanic i know...from reading threads here we thought epc solenoid and valvebody gasket...he tested it and found pressure problems so all the solenoids and gaskets were done...but nothing fixed it....now could it be a valve body problem? [ the last affordable fix left] or the REBUILD?he says its low pressure in the main system..A pump or leak on the way to the EPC..THANKS for any help
there is a large piston looking deal when you drop the pan. it has a 5$ oring around it that when it fails the transmission will drop into neutral. i find it happening in lower gears like 1 and R but it could happen in others too. it holds the lower pressure. You just pull that piston out replace the oring and reassemble.