Hello this is my first post and I am new.
I recently had transmission issues where I lost D gear. Transmission was rebuilt has new drums, forward piston which is the only non oe part used and used correct special tool to install, and a new solenoid. After completion of the rebuild I had a p0775 code and had delayed 1st to 2nd and delayed 2nd to 3rd . I replaced valve body as I had some concerns for its integrity as well as the separator plate for it. I now have reverse in D gear and I am a bit curious as to why. The fluid was good, I have tried swapping the old part out with the new one to the same result as well as warrantying the new valve body for another one. The unit also has been sleeved for the servos. I am questioning the forward pistons integrity since it isn’t oe. If anyone has any thoughts as to what a cause for this it would be greatly appreciated.

 

The 5r55s does not have a reverse piston/servo accessible from the outside of the transmission. . Both Servo's are for the forward gears. One is the intermediate servo that controls (4th-5th aka Overdrive), the other is for the 2-3 shift I believe. The reverse servo is inside the transmission, when you take off the pan.

The servos would not cause the problems you are describing.

Instead, focus on the valve body components. What brand of valve body did you buy? Sonnax is the best one. I would suggest doing your research on the corret parts on a reputable transmission-only website like this one. https://globaltransmissionparts.com/...on-valve-body/ or this one https://www.cascadetransmissionparts.com/ I've used both before for several Fords over the years. They are both stellar.

What date does the drivers door date show the car was built? There was a change made to the valve body in mid/late 08 for the 09. If you got the wrong valve body and/or separator place, or gaskets, that could cause problems like D and R not working correctly or D not working at all. Did you use new gaskets for the plate? Were they installed correctly and all the bolts torqued to 89 in/lbs? When disassembling the Valve Body there are two ball bearings as well when you remove the plate from the valve body. They act as check valves. If you missed one, it will cause problems. Either way, it sounds like a valve body issue is what you got.

For Solenoids,
It's best t to replace the entire solenoid pack on these transmissions, not just a solenoid. They require adjustment to work properly. DO NOT buy aftermarket junk (that includes Dorman). Buy a Bosch pack or Motorcraft Solenoid pack only! Bosch makes the packs for Ford. The Bosch PN is the 7G391-A. Look around to get the best price.

 

So I have put 2 different oem valve bodies in it and replaced the solenoid pack with a new oem one. The valve body is torqued to 89in lb as well as correct sequence. Solenoid pack is also torqued correctly and in correct sequence. When I put the first valve body in it had reverse in all gears except P. When I put the second one in I just have reverse in R and D and nothing in the manual forward gears. Each valve body also came with a new separator plate which did have the check ***** . I have also looked at what the pcm was showing when I shifted into each gear and it was correct.

 

It's hard to believe that after two valve bodies plus the original, and one or two solenoid packs you're still having issues. It sounds like a problem in the transmission itself.

I presume you have the correct valve body for your year (2007) They look identical and will bolt up interchangeably. They will not work interchangeably though.
Casting number on 01-'08: RF1L2P 7A101GA or RF5L2P 7A101CA
Reference: https://www.sonnax.com/tech_resource...identification

I presume you know the proper refill procedure for the transmission.
I presume when you replaced the filter you made certain to remove the old O-ring.
I would say it's a range sensor issue but, if the PCM is showing the correct gear, that's not it.

A trans shop would test the line pressures of the transmission.

This is how complex the 5r55s gear shifts are. Manual shift would override the electronics of it all but, if you have the wrong casting number, the fluid will get moved around incorrectly.
https://www.transmissiondigest.com/u...l-engagements/

Beyond that, the choices are, tranny shop, or swap out the entire thing for used trans from LKQ or something.

 

Ran across this and thought of this thread.
Transmission pump.