[hayjayhorses]

what year truck? how many miles? stock or modded tranny? Any tunes? What dose your tranny fluid look like? Dose the ATF smell burnt? Is your ABS light on or dose your speedometer needle ever bounce around? If you post the answers to these questions you will give the people who read this forum a little more info to help troubleshoot your issue.

When you say "falling out of gear" dose it fell like the tranny is going in to neutral, as in no drag on the engine at a stop; at this time dose the engine idle up?

As for putting the truck in park and reving up a couple hundred RPM. Sound like the (1) Torque Converter (TC) may be pulling harder then it should, or the (2) PCM thinks the truck is still moving,

(1) In my '00 F550 about 1500 miles before my tranny blew, a few times I noticed at a few stops I had to really push on the brake like the TC was pulling hard and the engine sounded/felt like it was fueling more to maintain an idle, when I put it in Neutral the engine would rev up then go back to idle. Have you heard any growl noise from the tranny?

(2) when I put my truck in to Neutral while still moving it will rev up, but it will rev to 1600-1700 rpm.

Good luck, I hope it's an easy fix, My tranny came apart 1000 miles from home with 9 horses in the trailer.

PS: this is why I am putting a 6 speed in my F550