Accessing/Changing Trans Modulator - need lift?

[jgroover]

So i'm assessing the work that needs to be done on my car so i can plan/budget accordingly. One of the things i need to diagnose is my harsh shifts. I have tested the end of the vacuum line that leads to the trans (engine side) and it has vacuum there. I even left the line unattached and there is no change at all in the shifting so i'm assuming this:

1. The line is soft/collapsed where it enters the modulator
2. THe modulator is messed up.

So, do i need to take this to a shop to get looked at or is it easy enough to access with jacks and stands?

[Pete Burton]

You can do any tranny work with jackstands, and change the modulator without lifting it at all. But first, check fluid condition and level and buy yourself a miti-vac. Then, you can test your modulator and much more by yourself.

[tangofox007]

It certainly can be done with the car on the ground. Disconnecting the transmission cross member and lowering the transmission will allow easier access to the modulator. And I would recommend buying a new modulator valve pin (part #126 270 92 79.) It's very easy to break the old one when you remove the modulator.
If the modulator is original, don't bother testing it. Just replace it.

[dannym]

Hey,
I have read that you can damage your transmission by not following directions on calibrating the modulator. I can't say so for myself and many people seem to have done a straight swap without any major problems.

Here is a link to a thread I found in the archives:

MB manual for 123 vacuum modulator replacement

Pay special attention to the links in post #7.

Don't want to create panic here Just thought you should know what your getting into.

Danny