Transmission problem
1999 Ford F350 V8 Four Wheel Drive Automatic 300000 miles

The truck will go into gear. After a short drive distance it will slip out of gear or just rev up. I can turn of the engine and check the fuse that has something to do with the trans because i replaced it this morning and it worked for awhile. When i turn the engine on it will go into gear and go about half a mile then it strat slowing down even if you rev up the engine.

Might want to have a diagnostic scan done on the trans, it may be giving out on you or have an electric problem internally or with the controller.Even if the check engine light isnt on, there may be something in "freeze frame data" that will lead to your fix