A55F auto trans No 2-3 upshift

[rocco611]

I am in the process of rebuilding a 85 4wd wagon, went through the engine no problem, runs great. while I had the engine apart I figured it was probably a good idea to go through the 30year old trans as well, the seals couldn't be in great shape. I carefully replaced all the seals, rings and clutches , put it back together there was no visible wear on anything,although the seals were very brittle. I drove the car, have 1rst 2nd reverse and 4wd. but it will not shift into third, doesn't slip , just doesn't shift. I pressure tested the trans, line pressure , gov pressure and throttle pressure all within normal range for 1,2 and R .the service manual suggested the problem would be the 2-3 shift valve .I cleaned the valve body during the rebuilt all the spool valves moved free, everything in the right place. I picked up another transmission , a 2wd version that was known to be working, swapped the valve body into the 4wd, didn't fix it. pulled the transmission out, and carefully compared the assembly to the other trans I bought. all the check balls are in the right places, no torn seals, pressure tested the servos all good. governor valve moves freely, all the pressure tubes seated correctly. I have rebuilt transmissions before, never had a problem, hmmmmmm figured if I took it a apart and carefully inspected everything I would find what I missed. any Idea's ?

[Mark]

I'd check to make sure the mechanism that shifts the trans and the throttle link are adjusted properly. The service manual has instructions. The things circled in red:

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You're braver than me. When I took mine apart to replace the governor/coupling, I avoided even looking at the valve body and just replaced the o-rings/seals.