JoFreed

Hey guys, new to the forum. My younger brother and I just got ahold of a 1992 f150 with the E40D transmission. It runs fine and engages into drive but after driving it for a bit, the transmission feels like it pops out of gear and free revs. We have to pull over, put the truck in park and shut it off for a few minutes. After starting it back up, it will engage just fine into drive and we'll make it a bit farther down the road before it pops out again. We read the MLPS (manual lever position switch) could be the cause of this so we replaced it but to no avail. Any tips or ideas on what to try next would be greatly appreciated!