Yeah, my tranny is finally happy thus I am happy

[Biodiesel300TD]

I changed my tranny fluid and filter. Re-adjusted the modulator. Now the tranny shifts firm on all shifts. It was flaring on the 2-3 and 3-4 shifts particularly when it was cold. So, I'll see how it goes next time it I drive it when it's good and cold. It's been a long haul to get it there. Been chasing it down for nearly a year now. It used to slam so hard the drive shaft hit the floor.
It is leaking fluid out of the bell housing. So I am not in the clear yet, but I can certainly keep adding fluid.
If and when I go through this again it will be a much faster process.

[Biodiesel300TD]

Here is what I did to get the tranny shifting nicely. In the order that I fixed the problem.

1. Replaced every rubber vac connectors and 3 and 4 way connectors I could find.
2. Found a couple of vac lines that were disconnected.
3. Replaced both check valves in the door lock system
4. Pulled the dash and replaced the diaphrams in all the climate control actuators.
5. Adjusted the bowden cable.
6. Rebuilt the vac pump.
7. Replaced the 3/2 way valves.
8. Replaced the passenger lock actuator.
9. Replaced the tranny modulator and pin associated with it.
10. Adjusted the modulator.
11. Adjusted the bowden cable.
12. Changed the tranny fluid and filter.
13. A last but not least adjusted the modulator again about 2-1/2 turns. It was way off.

A lot of the thing I fixed were seemed to be okay but as I replaced parts that were broken or not functioning other part would become the weakest link and quick working. The passenger lock actuator and tranny modulator are two examples. They both worked fine untill I sealed up other leaks.

So there is a list of things to check for you guys with shifting problems.

[Ara T.]

Glad to hear it. I fixed all my vacuum leaks and got the door locks working perfectly but now the transmission shifts way to softly and sloppily! I've been tryin to figure out this transmission vacuum modulator but haven't been able to find any decent pictures of it online, but know that it is on the driver's side of the transmission, can you tell me if it has a cover or something that I have to remove?

Also my trans seems to be inconsistent in its shifting. One minute its shifting perfectly with solid shifts throughout the gears and the next stoplight it will shift lazily even under full throttle. Perhaps the vacuum line to the modulator needs replacement.

[Biodiesel300TD]

The modulator will look like on of these two. I don't know if yours is green or black. But basically all you will see is the colored part. There is a little rubber black cover over the adjustment key. You pull it off to adjust the modulator.



If the shifting is inconsistant you probably still have vac leaks. I would check the modulator itself. You can do that from the engine bay. There are two black lines that come out of the vac control valve near the injection pump (atleast on mine) The one that goes down behind the engine is the one that goes to the modulator. Pull vac there if is doesn't hold any it needs to be replaced. Mine leaked so bad I couldn't pump the mity vac fast enought to get it to read any vac. If you end up replacing the modulator there is a plastic pin that you have to replace to. Here is the part # for the one I needed. AT Modulator Valve Pin-126 277 93 75. I used the green modulator so if you have that one you will need this pin.