2003 Sport Trac 5r55e 4x4 w/ no reverse nor engine braking

[jdjr131]

My sport trac has lost it's reverse and it's 1st gear engine braking. I'm having trouble diagnosing what's wrong. I tried installing a rebuilt valve body w/ rebuilt solenoids too because when I took everything down from underneath, looking behind the reverse servo it looked like the reverse band was still there and pushing a screwdriver down the hole gave some resistance. How much resistance is the reverse band supposed to give? Additional when dropping the pan there were no bits of reverse band or sprag floating around. I did also buy the improved seals for the reverse servo. Alas, none of this has improved the reverse situation.

I also installed the reverse servo with some resistance because I did not realize I probably have to put the servo in the freezer prior to installation, so could this installation method be a potential issue?

So where do I proceed from here? Do I try to once again install new wiper seals after putting the servo in the freezer? Could it potentially be an issue with alignment with the band? The servo pin seemed to be in good shape when I pulled it. Could it potentially be an issue with my transfer case or sprag (some things I see mentioned on the forums). I'm considering taking it to a shop to diagnose it, but I am operating on a college budget. Or do I drop the transmission, get a repair manual, and try rebuilding this thing myself? Would it be worth it to pickup a pressure gauge and diagnose what's going on?

Or is it even worth trying to diagnose this transmission? I'm considering swapping in a M5OD-R1 because at this point I'm kinda done with autos (plus I hear it's a relatively easy swap because of how much these STs share with the ranger); how much could I get a for a reverse-less trans w/ a rebuilt valvebody to recoup costs? In addition to the reverse going out, I've had the flashing O/D light which I'm still procrastinating on getting a proper OBD2 reader and trying to diagnose it with forscan. I'm thinking a bad torque converter.

My parents had the transmission replaced or rebuilt (I'm not sure which one) from the local aamco a couple years ago so I'm not sure why it's decided to go out now.

Any potential help is appreciated, thanks.

 

[JK080]

I would recommend having the codes read first but it sounds like it going to be a problem with the low band itself.

Swapping in a manual is a bad idea, if you were going to attempt that and you can install the valve body you should be able to pull the transmission out and fix it yourself. Hopefully AAmco did a quality build and the only issue is a failed band, parts can fail at anytime, even new ones.