Hey guys, my family has owned this 1971 Mercury cougar for the last 40 years and we've always had an issue with it. After putting the gear selector into drive it always takes a while to actually engage. Back in the 80s it only took about 10 minutes or so. Now it takes 30 minutes to an hour and only seems to be getting worse. Once it engages it shifts nicely and doesn't seem to slip. If I stop for gas or something after it's been engaged for a while it doesn't cause problems when I restart the car. It engages into reverse perfectly as intended even when cold or if it hasn't been driven in a while. Also something to note is when it's in gear, reverse or drive, after it's been engaged, it seems like the transmission is really grabbing and trying to move even though I'm just idling, drops my rpm by a good 300. Any ideas guys? Anything is appreciated. I already flushed all my fluids multiple times, I've added Lucas transmission fix and my fluid levels are topped off. I also checked my modulator and my vacuum and it all seems to be in working order visually

 

What about the trans filter?