Take it to a tranny shop. Get an estimate. It could be several things. Pump bad, valve body needes replaced, one way clutch bad, bad servos, bad pressure relief valve and so on.
my 1997 ford escort wagon 2.0 i put a transmission in it it changes low second but not drive what is the problem
Could it be the clutch? Or cable?
When my 1995 would not shift out of park I called a local dealer and ask what possible causes could be (they were not so pleased with giving free advice) the first suggestion was to check the fuse for the break lights. It was blown, I relpaced it and "magically" the issue was fixed. If your car still shifts I would check the bulbs first.
its a shift light for a manual trans. means opimum rpm for shifting to higher gear
If it is an automatic the dipstick is right next to the brake fluid master cylinder reservoir. If it is a stick shift there is not dipstick.
Check for play in the shift lever and linkage. If is shows signs of play or looseness adjust it, or, perhaps it lacks or has too much lubrication at the joints and friction points.
The shift solenoid is under the console in the shift assembly.
I'd bet that the clutch is dragging, not releasing fully.
Our 1993 Ford would not randomly (or so we thought) shift into overdrive. We eventually figured out this happened when the headlights / parking lights were on. We then traced it to a bad ground in the parking lights circuit. We fixed the ground and the shifting issue was fixed. No joke.
Inside transmission
what would transmission not to shift in to overdrive
when my car wouldn't shift it was because the cat.converter was cloged