skimo0104

hey guys i have rebuilt my transmission on my 01 dodge ram 4x4 once and now about 24000 miles later it no longer shifts when i put in drive. i have to manually shift it and even then i have to work at it.. it will not go into overdrive, and it will not downshift at all. ive heard it is some solenoid sensor, but no specifics on it were given so im looking to mopar knowledge to see if anyone knows what it is??/ thanks guys !