transmission will not shift into OD

Sounds like you probably have a sticky OD push rod... It is the mechanism that engages the overdrive. Have you tried to change the fluid? That could do wonders. It could fix it.

I'm having the same problem with my 01 Durango R/T,I replaced my lockup and OD solenoid because it didn't work at all and now it only kicks in about 20 minutes into a drive,I've also changed my throttle positioning sensor,the sensor on the back of the throttle body I can't remember what it's called looks like a coke or something and speed sensor and nothing is fixing it,could it be the ECM?

I have a 2007 dodge 1500 ram, when I'm driving, it will not shift into OD. It will shift through the first 3 gears smoothly, but snot shift into OD. I bought a second transmission to fix the problem hopefully. But it still does the same thing as the other transmission. it would not shift into OD. Is it the ECM, does it control shifting

Check the plug on rear axle(top of it), may be dirty or need changed

I was playing around in my 1996 dodge 2500 it’s a 12 valve Cummins I’ve never had it shift into over drive till that day I just drove around slow hit a couple of holes when I got on to the black top it shifted fine then it shifted to over drive I parked it and woke up the next morning and it won’t do it no more what’s going on

My 2000 Ram 2500 with V8 magnum engine won’t shift into overdrive until it’s been driven at least 20 miles. I replaced the trans filter, oil and both the solenoid and sensor that are in with the filter with no change. Has anyone figured this out yet? I need help