I have a 2002 F-150 5.4L 4x4. It has the 4R70W transmission. A few weeks ago I was driving it to a friend's house and as I was about to turn left into their neighborhood it didn't want to go. I revved it up and it worked and I managed to get it to their house. I had a transmission shop tow it to their shop. After about 4 days they called and said it needed to be rebuilt for $2500 or they found a used tranny with 140k on it for $1500 plus labor to install it which would be about the same cost as rebuilding it. I told them I didn't have the money to do it then and paid them to tow it to my house. After a few days I noticed a large amount of gear oil under the differential. I thought it was leaking from the housing so changed the gasket. It turned out to be the pinion seal. Changed that. Stopped it from leaking found that the reason it failed was the axle vent was clogged and the hose was missing completely. While under there i saw a small amount of tranny fluid on the driveway. It wasn't leaking before going to the shop as well as the exhaust leaking water. I tried taking it for a drive because when it first happened all forward gears and reverse was not working. Went out at the same time. Got in, let it warm up. I drove it down the street, got to a stop sign, stopped and made a right turn, then again no forward gears. I backed up down the street and then reverse stopped working. I pulled it back home. Today i wanted to try to get it back in the driveway instead of sitting by the street. Got in it put it in reverse and it backed right up. Seems to not work once the tranny warms up. Also before all this the torque converter had the notorious shudder. Does the tranny need to be completely rebuilt? I figure I would replace everything that comes in the rebuild lot even if it's just one part causing the problem. Might as well while I'm in there. I just wanna make sure it's the tranny and not the TC or anything. Any help is appreciated.

 

Have you checked the hot running level?
Have you had a check for transmission codes?
Some effort has to be put forth for any decision to be made about the issue.
Good luck.

 

Fluid level is fine. I did hook up an OBD II code reader and no codes are coming up so I guess all sensors are working fine.

 

If it was a generic OBDII code reader it won't read the transmission codes. So all you can determine from that is that you don't know if there are codes or not.