Just replaced the window regulator -- driver's side -- on my '80 300SD. I had to cut my own holes in order to access the bolts holding the motor to the regulator; your 116 may already have the proper holes, mine does, now.

For sure, one cannot get the entire mechanism out of the door while those two components are attached to one another. Even after having the access holes, though, mounting the motor after replacing the regulator is no walk in the park. I have these rather large, muscular forearms -- village smithy types -- and the inside of the door could not accomodate all that beef and metal. Just too much of a hassle, and too little room.

My solution was to take the regulator off, and remove the front window channel. By front, I mean the one nearest the door hinges. By doing so, I had enough room inside the door to re-install the entire Rube Goldberg rig, motor attached, without the first drop of blood being spilled. Easy to install the channel once the regulator/motor are tightened up.

I have learned a lot from reading this forum, and could not own this car without the invaluable input from the seasoned techs and owners. I hope this little tip can help someone down the road.

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1980 300SD 146K miles.