I have a 2004 F150 2 wheel drive with the 5.4L V8. Just recently I had to replace the Tailshaft Housing because it was cracked but the mechanic said that my transmission itself was fine. This past week my truck ran beautifully and just the other day when ever I would stop and try to go it wouldnt catch into drive. Eventually it just gave out completely and wouldn't catch at all but it still drives in reverse with no grinding or weird noises. The thing is that there is no leak at all. Is this a sign that my transmission went out. I heard it could possibly be a computer thing.