97 caravan no reverse and cant roll vehicle in neutral with key on
 

Have 97 grand caravan sport 3.8l engine 4 speed transmission just out of blue transmission starting acting up. vehicle has no reverse and neutral was like it was in park can not roll car in neutral. forward gears the car wanted to move. first change fluid and filter there was some metal shavings. second changed in and out speed sensors. third changed TCM and transmission solenoid. forth checked linkage. No change . Any ideas internal problem?
thanks