On three occasions my reverse vanished only to return a short time later. First occurrence was after a one hour drive at highway speeds on a summer day. I shifted into reverse but for some reason it didn't engage. I did have forward and drove home discovering the reverse had returned. A month after the problem reoccurred twice in one day. Drove at normal speed on a dirt road for 45min. I shifted into reverse and again it wasn't working. A short time later it returned. An hour later it disappeared again only to start working a short time later. It hasn't happened since but kind of not a great feeling when planning a trip. Truck is a 02 F150 5.4 4X4. Any idea's anyone???

 

My idea is that the seals in the reverse clutch are failing. If I'm right it is going to do this more often until reverse doesn't work at all.

 

Had considered it as a possibility but hasn't happened since last summer. Heat related I wonder?