RE: What Model Transmission?
That external filter is preventative mainenance only. It's not going to fix your problems. You need to drive this car, not run it around the block. The tranmission needs to get hot. Get that fluid up to 200 deg (aprox operating temp) Get your DMV paper work and take this car out for a day. Run it at all the different speeds. Don't be afraid to kick it in the a__ a little. You might be surprised how sticky things in an (old) automatic transmission can free up when you use it. Worked with mine.
Run it !!!! I make it a point to run my car at least every two weeks weather permitting. And I run it right down the free way. 10-15 miles out and then back.
1960 Convertible (Orig owner)