How to remove heater core from heater box?
 

My 1991 350SD has a bad evaporator. I got the heater box out -- what fun that was!!
According to the manual, I am supposed to remove the heater core before I remove the evaporator.
I took the heater core cover off and took the support for the three pipes off. There is supposed to be a retaining bracket inside the area where the heater core is and I am supposed to unscrew it and remove the heater core.
However, I have nothing that is screwed in. What I have is a shaft that goes through the opening that is attached to a vacuum element that rotates the shaft.
The heater core will not come out because the bottom pipe hits the shaft when I pull it up. It seems like the shaft has to be removed.
Has anyone done this and can tell me how to get the core out?

First, Lock yourself in the Attic,so no one will hear your Cry
 

No, Really...If you've gotten the Heater box cover off... You're much more patient than I'll be in 6 or 7 re-incarnations. 'Job Well Done!

I Don't have any access to the W126 Chassis HVAC manual.
(Or ANY W126 Manuals)

I believe you're talking about one of the operating rods for the Vacuum Pods ?
[Gently, remove it from your work path]

Just for fun,inspect the engine compartment side of the FireWall(s?) to make
sure one of the Gnomes in Stuttgart didn't SECURE the rod on the other side
with a nut.

All the MB Vacuum Pods have got to be the same,same.
(Germans hate Non-Conformity,and standardization is kinda a religion over there)
they are kinda a Twist lock release design.

These are a couple of GSXR's AND SIXTO's Vacuum pod Tutorials for W124 they should be
generic enough to help you:

http://www.peachparts.com/shopforum/showthread.php?t=245697&highlight=Vacuum+pod

http://www.peachparts.com/shopforum/showthread.php?t=246382

And

http://www.peachparts.com/shopforum/showthread.php?t=35373&highlight=Vacuum+pod

http://www.w124performance.com/images/W124_dash/

I ended up getting my evaporator core replaced. What a PAIN!!

I had to pretty much take the whole airbox completley apart to get to the evaorator core. Now I need to get the airbox back in the car and get the cooling system filled again so I can get it to the mechanic to fill it up with freon and see if it will hold a charge now.

It better after all that work. If it does, then I'll get it all back together. I saw a post for someone that got the dash off in 2 hours. for me it is more like a day....

Save the charge, see if it will hold a good vacuum, if so, then freon.