I have a buddy's 99 250. It's not shifting into 3rd when cold. Once this thing warms up it shifts fine. It's throwing a P0782. The weird thing is once it starts not shifting , you can go in clear the codes and it's back to shifting fine. He took it to a trans shop and they cleaned the 2-3 valve and said it's good. Replaced the shift solenoids, and switched out a PCM to make sure that wasn't an issue. Would this be a wiring issue. The weird thing is, is once you clear the codes it's fine until it throws the codes again.

Thanks.

 

If it was a wiring issue it would have a code for a wiring issue. This issue is mechanical. There is something wrong with the direct clutch. It's possible that the feedbolt under the valve body that feeds pressure to the direct clutch has loosened, allowing pressure to the clutch to bleed off. It is also possible that there is a damaged seal inside the direct clutch.

 

Thank you Mark, we will take a look.

 

He is going to get it looked at by a local diesel shop that I use, based on what you said. I finally got the full story, so I will post it. Just to make sure we are still on the same page.



About my truck 1999 Ford F250 Super Duty 7.3L Auto Trans rebuilt 2 years ago With Suncoast Diesel transmission parts- triple disc torque converter and other upgraded parts $6500. Mostly stock motor other than 5in Exhaust system, K&N intake, DP tuner, larger Trans pan, bigger tires 3 Months ago I went out to my truck and fired it up it was about 50 degrees outside. I drove off as I got on the main road it would not shift into 3rd gear I pulled over and check the trans fluid looked good didn't smell burnt and still looked nice and red. After pulling back out on the road it shift fine up and down through all the gears. I took it to the shop where I have all my work done (I have been going to him for years and he knows Power strokes very well) He also was the one that did my trans rebuild on 2 of my trucks, He said it needed a shift solenoid He replaced it and changed the filter and fuel. After a couple of days it did it again, It would shift from 1st to 2nd gear but not into 3rd I tried to make it shift by giving it throttle and getting up to red line it would sometimes shift it would as shifted into 3rd after pulling over shutting off the truck and taking off again. My over drive light was flashing which I knew meant my trans had trouble codes. Over the course of a week it would sometimes not shift into 3rd and other times shift fine. I called my diesel guy and told him it wasn't fixed and brought it back to him. He did some test and said he needed to pull the trans out and take it apart. He did so and had the torque converter sent to Suncoast and had them rebuild it he also said one of the valves inside the trans was slightly sticking and sent it to a shop to be repaired. He said the Trans shop put everything back together and the trans was working great. They reinstalled it and said it shifted good. I took the truck back and the next morning same thing wouldn't shift into 3rd gear. I have since learned that if I let the trans temp warm up to 150 degrees (I have a trans temp gauge) It will shift no problem. My shop told me to bring it back up and they would look at it again. $1800 later he called and said he thinks it's the wiring or a sensor but was busy and wouldn't have time to look at it for a few weeks or so. Frustrated I picked the truck up and brought it to another shop he did a quick test and told me he thought the computer needed flashed by Ford. I have three 7.3 trucks that I use for work 2 being 1999 super duty (Both built in June of 1999) I went home and took the PCM out of that truck and swapped them I know there are something that might not work the same due to each truck being programmed on its own but tried it and still wouldn't shift into 3rd unless I warmed the truck up. My other truck which I pulled the PCM from was stock no tuner on it which I could tell my truck was back at stock when I switched PCM. I put the PCM back in the trucks they belonged in. I also replace the speed sensor on top the rear end. I then took the truck to a transmission specialty shop to take alook at it he had it for 2 days and called me he said he got 3 codes out of it which where P0603, P0782 & P0471 he also said if he reset the trans codes it would shift fine or if he let it warm up it would shift fine. He also said his computer said the EPC was going to max pressure of 70PSI (I believe that's what he was saying) He felt like it wasn't the trans and that is may be the PCM or something electrical but also was pretty booked up and said maybe check with the ford dealer (Bad idea) When I took it home I hooked up my scan tool (just a cheaper one) and it gave me P0605.
I brought it to the Ford dealer and gave them all the information above including all the codes and everything I have had done and tried along with how I can make it shift by warming it up or resetting the trans codes. They called me and said it needs a new trans in it I asked if the tech had gotten all the information about what was going on and if I could speak with him. He didn't not have any of the info I gave. He said he would check the wire harness and test to see if when the PCM is calling for the shift that its sending it to the trans which it was he said he check some of the wiring and connections and $550 later said it needs a new trans still. So I brought it home.

 

With this new information my best guess is a sticking 2-3 shift valve.

 

Thanks i will relay the information.