Up until a few days ago, I’d been daily driving my 93 f150 w 302 and AOD transmission (75k miles atm). When I first got the truck, 1-2 and 2-3 shifts were smooth, but shifts into OD were a bit hard. The truck only had 64k miles and had sat for a while, and I was told driving it more should smooth out the shift

The shifts did start to get smoother; part of it was me also getting a feel for what speed&rpms it liked to upshift into OD and timing when & how much I let up on the throttle

But, about a month ago i started the truck and noticed it wouldn’t shift into OD - it would just continue to pull in 3rd. Would only happen when truck was warm (driven for a bit, shut off then started it again not long after). When it first started happening it took me turning the truck off, waiting a bit and on restart it’d shift fine. The problem was intermittent until recently. If I let the truck sit for a couple days it’ll shift into OD fairly smooth; again not as smooth 1-2,2-3 but much smoother. Soon as I turn the truck off and start it again not long after, it won’t shift into OD.

Was surprised that when i checked my transmission fluid, the level at both cold and operating temp showed way above the normal range (checkered portion). I never added transmission fluid since i'd bought the truck about a year and a half ago, and could've sworn when i checked the level a while back it was within the normal range but that was probably a year ago not long after when i first got it.

Given symptom presentation, I think the 3-4 shift valve may be stuck but I’m at a loss. Any help is appreciated.

 

Did you check the level after going P,R,N,D,D,1, then shifting back up through each gear? And then checking it while running in park?

 

I did initially; will check again tomorrow to see if it's replicated

 

If it’s overfilled, drop the pan or suck out the fluid till it’s correct. My AOD took 4 quarts and one liter I think after dropping the pan but if you drop the pan keep an eye on level as you fill it since you may need more or less than I did. Make sure you put at least 3 quarts in before starting it as well since that’s the initial fill (according to AMSOIL website) if you drop the pan. Overfilled fluid can screw up a transmission just as bad as under filled I hear. Sorry if I’m just saying things you already know.
I don’t know much about transmissions, so someone else has to tell you about things it could be besides fluid.

 

First make sure the TV linkage is free and not binding.If the fluid shows being overfilled and you know the level was once good, I might suspect a restricted filter.

I would try a chemical, allow it to work for a while to help with a possible sticking valve body. Then drop the pan, allow fluid to drain as well as draining the torque converter if you want a complete change. Check and make sure the valve body bolts are torqued to specs. Change the filter, refill with MERCON V and road test.

Other possibilities causing no 3-4 shift issues include:
Direct clutch problems, valve body issues, governor leakage and 3-4 accumulator issues involving hash 3-4 shifts.

 

Took it to a transmission shop thinking I'd need a rebuild. Turns out there's a couple screws holding the gear selector in place on the column that were loose. Mechanics said they see this often with older ford trucks. Truck must have been slipping from OD to D as the gear selector was weakly held in place. Also explains why I would try to put the truck in reverse and it would be in neutral. Might not be describing this as well as I could but truck now runs and shifts great no problems