CSprain

I have a 2006 F150 5.4 4x4. 197,500 miles. It was a company truck for the first 180,000 miles, lots of highway life. I have been noticing recently (past 2 months) when shifting into reverse it seems to take longer than usual and it will shake if you throttle too quickly. Last night I was towing a flat bed car hauler with a small tractor on it. Only about 70 miles. Anyways I was in a hurry and forgot to shut overdrive off. Most of the trip was at 55mph or so and not too many hills. When I got home I had no reverse. Fluid is full, not burnt, and has a good color too it. I have not ever flushed it in the last 18,000 miles or so that I have had it. All forward gears worked fine the whole 70 mile trip home. After I had no reverse I simply parked the truck for the night.

My question is what are your thoughts?

I do believe I have everything to complete pulling the transmission and reinstalling a new, used, or rebuilt one. Does anyone have a walkthrough? Usually will make things go a little smoother. (I used a walkthrough and completed the phasers and timing components in a weekend.)

Are all transmissions interchangeable within the 04-08 F-150s as long as it came out of a 5.4L 4x4?

I plan to bring it to a shop here this Monday depending on what is open.