92 dodge ram 150 not shifting

welL what transmission is really there, 2001 year.Dodge RAM 1500 pickup I guess.
many this old 21yo have the wrong box, and wrong gear ratio's now.
or has TV cable or has vacuum modulator bad.
as transmission evolved fast, the cable TV and modulator was no longer used, (and both delay shifts)
the E box, TCM that knows load on engine
this is mix of old and modern Eboxes

dodge name is 42RE; Trans. code 46RE
and knows vacuum and throttle angle and shift by engine load
and throttle angles and by road speed. (VSS)
scan the PCM/TCM yet,see if it is not happY> that be first of sure and Ebox.
it has TV cable and gov. modulator that both can fail.
cable rusted and suck open is common'
it has EPC tool pressure mudulator that if fails so do shift points.

When did you last replace trans filter and fluid? Dirt may be causing shift valve to stick.

Did you check the universal joints. Then try a transmission shop if you think it's the trany. Should not be shifting into 3rd at 20 mph for one thing

transmission clutches bad for third gear operation. needs trans overhaul..

try replacing the fluid and adding some LUCAS brand stop slip to the fluid also check the transmission mount and motor mounts

Most likely the second gear section of the transmission has gone bad. There are 3 or 4 different gear sections or assemblies in an automatic transmission, when they go bad, they go bad.

the valve body has a vavle stuck in the trans you could take it in and have it fixed at a trans shop or take the pan off the trans figure out which is stuck free it up and maybe put a spring behind it if possible on that model.

It depends it could be a bad servo for the 3rd gear trans or it could be that 3rd gear clutch is worn out
Only way to sepearte these problems is to have the trans pressure tested and distinguish the problems

Your description does not sound like solenoid issue.

I need to know what your vehicle uses for throttle position indication to the trans. IS there a rod from throttle body area to the trans? If so, adjust that to have slightly less effect.

If not, look for vacuum leaks or cracked hoses to trans...

Doc

ummm i would say you need to adjust your trans shift cable, check your fluid level, and the problem i had with my dodge was similar to yours... it was my 3rd-4th actuator spring, it had broke and couldnt hold the pressure to keep it in gear