I have an 01 F250 with the 7.3 and 4r100 auto transmission. When I'm in overdrive and build up speed, let off the pedal, it drags down normally, kinda like the engine is braking until it gets to about 1200 rpm's or so, then drops to an idle. That is normal from what i can tell. However, if i have the overdrive turned off, when i let off the pedal, it will drop on down to an idle no matter what speed i'm going. I've tried building up speed in overdrive then letting off the pedal, then manualy turn overdrive off and it will drop to an idle. Shouldn't this act as tho i downshift and go from overdrive to the next lower gear?
Thanks in advance for any answers........NUB......

 

Has the tranny always behaved this way as long as you've had the truck? When did you buy the truck? Did you ever have the PCM re-flashed by a Ford dealer? I have an early 99, and I was going to get a re-flash because of a TSB in late 2000, but I found out just in time from a fellow RVer that got his done first, that it screwed up the coast down shifting and he couldn't use his exhaust brake. Sounds very similar to what you're describing. Even worse, Ford couldn't put his PCM back to the original program!

Also, try manually selecting 2nd from about 45 mph and then coast down to see if this gives engine braking.

 

I had the same problem way back at like 30K, The dealership tried to tell me it was normal. I could drop it into 1st gear at 45 and it would drop to idle. I took the mechanic for a ride in mine, and showed him exactly that. Then he took me for a rise in a new truck to prove that it was normal. When we peeled our faces off of the windshield, he says "ok, we'll fix it" Amazingly, the next day, there was a bulletin from Ford about some kind of clip either in the TC or on the shaft that falls off. They pulled the trans and replaced it with a new style clip, and no more problems.

 

I've had the truck almost 3 years. It had 60,000 mile on it when i got it. Got stuck in Houston on a Sunday morning last June. Ended up having to have the trans rebuilt then. To be honest, Ive never noticed it doing this until just recently, but it seems out of the ordinary. I just took it for a spin and if I pull it down manually into second at about 50, it catches and the rpms go up for a bit, then drops to an idle. Tried doing the same for 1st gear and it revs also. The only place that seems odd is when i have it out of overdrive. Not sure if its been flashed or not. I have no overdrive light flashing or anything like that. Thanks for any help you guys can give.......NUB.......

 

The problem is a snap ring that should be holding the coast clutch together. Most likely it's come out of it's groove and the coast clutch isn't working.