I have a 2005 Ford ranger 4x4 with 4.0 auto. The truck runs and drives good. I've owned the truck for about 3 years. I purchased it from a small garage, that has bought it from a long-time customer whose husband passed away at which time the garage had put a newer engine in it, the rest of the truck including a transmission have 206k miles.. I work with the truck every day and for the last year the truck will randomly "jump into neutral" shifts good never slips or anything even towing but randomly will just go into neutral not on the shift indicator visually but it will not move even if you put it in reversed or second or first. Whatever it does, nothing you have to put it back in park. Let it sit for a minute and then back to drive and it works fine. It seems it happen more often when it is cold in the morning. If I only let it run for 5 minutes and take off it almost always doesn't. Before I hit the end of my driveway. I'll have to sit and park for about a minute and then it'll be fine. But I've also had it do it when the truck was hot many times Occasionally I will be driving 55 down the road and it will jump into mutual. Usually before I cost to a stop it will jump back in gear. I have changed the transmission fluid and filter. It did seem to help for a little while. If that's a coincidence or not, I'm not sure but it is full of fluid and is clean. I have also adjusted the bands with the two studs on the side of the transmission that seem to do nothing to help. Today the truck ran for 10 minutes in my driveway. I drove about a mile up the road. It revved up because it jumped into neutral. I sat for probably 2 minutes before it would go back into gear. Seems to be taking longer as this issue progresses. I am unsure if it is a torque converter issue or what? I'm not sure if it's the original torque converter or if anything is updated when the previous owner changed the engine. But again other than jumping international it does not shift bad or slip or shift hard or anything. Sometimes I will drive 2,000 mi without it messing up at all. Other times it's everyday. Does anyone have any idea what it could be?