Vacum Modulator Replacement 92 300E
 

I took out the old vacuum modulator on the tranny on my 1992 Mercedes 300E 2.6. It was very difficult to take it out and I had to apply allot of pressure. Now, I cannot install the new one as it looks like it barely fits. Overtime I try I do not have the strength to do it. Is there a method of installing it? Any helps appreciated, Ive been working on this for several days now and just cant install it. Thank you!

I'm not sure what's going on that it's that difficult.

These links may help:
W126 Transmission vacuum modulator replacement - Mercedes-Benz Forum
DIY W201 Transmission Modulator Removal, Replace, Trobleshooting & Common Problems - Mercedes-Benz Forum

Modulator
 

The o-ring that is located in the beginning of the modulator is preventing me from sliding it inside. Unless I slip the o-ring to the end then it goes in no problem. See in the picture thats where it is when I received it. I just won't go inside and I am slowing destroying the 0-ring because It won't go inside if its just like you see in the picture.

Is there any chance that the old O ring from the old modulator is still stuck in the transmission case?

Everything came out when I took the old unit out. Its perfect there. Are they the same for all Mercedes 124's? Maybe I have the wrong one? I have exactly what is pictured above, a red unit. Like I mentioned before when I slide the o-ring down to the end it goes in perfect. Should I use trans oil to lub the interior of the transmission so it might slide better? Thank you!

douse the O ring in a lot of ATF and then try to push it in. Make sure to reference the thread below. You may have the wrong intermediate part that is causing the bind

This is the thread from whunter
http://www.peachparts.com/shopforum/general-information/335721-722-xxx-transmission-vacuum-modulators.html