I have a 2002 F150 5.4L with a 4r70w tranny. Today i was leaving my friends house and a few minutes of driving after i came to a stop and then proceeded to go the engine revved up but it didn't accelerate until I revved it up to about 3000rpms but after 1st and 2nd gear it drove fine. While in 2nd gear and driving the rpms would rev up a little by their selves. I had to stop at the vet and pick up my cat. When I went to leave I put the truck into reverse but I didn't feel it go in to the gear and when I tried to give it gas it wouldn't go. I had someone help push me backwards and put it in drive and same as before. I tried putting it in reverse when I got home and same thing until I revved it up and it caught the gear and went into reverse. I checked the shift linkage to make sure the cable wasn't the problem and it seems to be shifting. The fluid is still red and doesn't smell burnt (I changed the fluid about 2 months ago, didnt flush it though). I took the pan down and though there was plenty of metallic paste around the magnet about a 1/4" wide all the way around (I'm assuming it has never been taken down and cleaned or had the filter changed) but I didn't notice any large metal flakes on the pan. It has had what I think is torque converter shudder that happens around 40 mph and then stops once I either accelerate past 45 mph or slow down under 40 mph. Any help on the problem would be very appreciate as this is my only transportation.

 

It can be low fluid, the internal filter fell out, or a failed seal, requiring a rebuild.

 

Thanks for the input. It got late last night so I didn't finish draining the pan but this morning i did and as I was emptying it I found the dipstick plug from the factory so I definitely think the transmission pan and filter have never been cleaned or changed.