Dodge Repair: dodge avenger trans., solenoid pack, dodge avenger

Question
do not know much about dodge trans. installed what looked to be a good 2nd hand trans. oil,seals, gears and filter looked new. the trans shift good for about 7 days. then it would not shift. installed a new trans control seloniod. would only shift up one time in drive after install of soleniod then it would stay in low gear.noticed that if i would run the shifter manual from park to low a couple times the trans would shift up in drive one shift and would not shift all the way out. then if you stopped in drive and try agian it would not shift.

Answer
Those transmissions are very tempermental and if they act up electronically they could go in to a limp mode that prevents shifting.  There's internal transmission failures, the trans controller, the solenoid pack, or even the speed sensors.  These speed sensors look about the same from the outside and one mounts between the solenoid pack and transmission while the other mounts further to the driver's side.  Both connectors look the same from the outside but once removed you can see a difference.

One important thing to keep in mind is that if you don't clear the fault codes in the controller and replace part after part then you will still have the transmission in limp mode.  A battery disconnect works sometimes other times you physically have to remove the codes using a scan tool that can access the transmission controller as well as the powertrain controller.

I would suspect that either the codes aren't cleared out and you've actually corrected the problem or you've transferred defective parts over to the new transmission causing your problems to transfer as well.
Doug