Need transmission help

[MacGyver]

I know I posed this in the stock 1gen section did know if i would get more help here.

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.

 

[wood1]

Did you check your fluid level? Also, when was the last time the trans was properly serviced (filter/fluid).

 

[MacGyver]

Thanks for the reply.

I have checked the fluid levels and they are in range.

The system has not been serviced in a while maybe 50-60k ago. I did check the fluid that came out when I changed the modulator and it seemed fine and not burnt.

What is puzzling me is the fact that its engaging when the vacuum line is disconnected.

 

[wood1]

So you can repeat removing the vacuum from the VM and replacing it and you get the same result every time? If you only did it once it could be a coincidence.

 

[wood1]

When the VM is hooked up does reverse engage properly or slowly?

 

[MacGyver]

So you can repeat removing the vacuum from the VM and replacing it and you get the same result every time?

Yes

Also reverse engages instantly (normal) with the VM hooked up.

 

[wood1]

OK, this is what the ATSG book says:
-Improper fluid level
-Manual linkage - misadjusted, damaged
-Low main control pressure (leakage). Forward clutch center support seal rings leaking.
-Forward clutch burnt/damaged/leaking. Check ball in cylinder/leaking piston seal rings.
-Valve body bolts loose/too tight
-Valve body dirty/sticking valves.
-Transmission filter plugged
-pump damaged, leaking.

I would adjust the bands, check the linkage, replace the filter/fluid and hope you find a problem with a VB gasket or a sticking valve. Personally in my mind, when I had problems and removed the VB I had already decided to rebuild it. Up to you. You could check the pump pressure too, if there is a problem with the pressure you might have to rethink your approach.

Gotta go to the gym, I will check in later.
http://www.explorerforum.com/forums/showthread.php?t=158160