I have a 2000 Dodge Durango 4x4 4.7 l. My truck started revving high during take off and lacked power, also there was some bucking while driving. Initially I had gotten a trouble code that stated Shift solenoid D was the problem. I went to find the part and a guy told me that it was dirty. I changed the fluid and filters and everything cleared up. Two days ago I pulled out of the parking lot and it revved high again I stopped at the red light and then it wouldn't move. I towed it home and noticed that the transfer case was out of gear and it wouldn't shift back into gear. I drained the fluid which was black I put in new fluid and then it shifted, But still revs like it's in neutral. I went to the junkyard and picked up a valve body for the transmission and replaced it, new filters and fluid again with no change. My OBD II scanner acted like it didn't recognize the vehicle. I put the old valve body back in and it still acts like it doesn't recognize the vehicle. transfer case acts like its working fine but transmission acts like it's not shifting into gear. Sorry this is so long. I am new to the site and would greatly appreciate any help anyone could give.

 

pm master tech he's the tranny expert here