Modulator questions for the Ford A4LD

[LonesomeSTX]

My 87 Ranger has an A4LD automatic in it. Since I got the truck it has shifted rough. It slams into gear when I put it in drive and reverse. It also shifts in and out of gear when I am on hills. It does it on flat ground as well but not as bad nor as often. I dropped the pan and it looked decent inside without any junks. Just normal material build up. Even though I do not have any fluid coming out of it, I bought a new modulator in hopes that is the problem. While I am doing some exhaust work I was going to replace it. However, do those symptoms sound like and adjustment problem instead? I am assuming the line pressure is too great and that is why it slams into drive. I have not had to deal with these very much over the years so please chime in on other possibilities you may think of.