Transmission help needed

[MacGyver]

I am having a weird problem with my transmission.

Specs are: 94 4wd 4 door Eddie Bauer. Its my DD and I do nothing but go to work and drive children around.

Problem:
In the course of 3 shifts from park to drive the it took longer and longer for the tranny to engage. Now it will not engage at all in any gear selection except for reverse. In researching here it sounded like I needed to check the vacuum modulator. After taking it apart I find no fluid in the vacuum line. Start it up to see if the line has vacuum and it does. Sounds pretty strong too. I decided to swap the vacuum modulator anyway since I have access to it. I did put the pin in from the old one.

Result? Still not working. Same problem will not go into any gear. So I pull the vacuum line again, start it up, put it in gear to see if it still has a strong vacuum and it goes right into gear. So now I am stumped. Half ass thinking says to leave the vacuum off and cap it since its working but I know thats not the correct solution.

I also checked the whole line from manifold to modular and there is no vacuum leak. So again I am stumped.

 

[FIND]

First off, what is the condition of your transmission fluid?

 

[MacGyver]

Seems like a good shade of red and not like its burnt

 

[FIND]

You are going to need to determine how much line pressure you have on your transmission. Outside overdrive, every gear change is controlled hydraulically, therefore, you only have a few possibilities, and most of them lead to a rebuild or replacement of your transmission.