Modulator questions for the Ford A4LD

[Lonesome7.3]

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.

 

[Draenor]

I dont have much experience with the A4LDs. I would start with the basics with the harsh engagement in drive/reverse. Check u-joints, transmission mount, etc. Could be the vacuum line to the modulator.

If it's line pressure, you'll have to get a gauge and check it vs. spec. The shifting problem sound like a valve not engaging properly. The valve could be worn, or maybe have an o-ring that is bleeding off pressure.

 

[Lonesome7.3]

I think I have it sorted out now. I have been driving it over the past couple of days after some repairs. It seems to be doing much better.