So of course, I recently broke something that allows the single cup-holder door to open and close properly. I mistakenly forced the front most side (closest to the radio) of the door down, rather than depressing the rear/upper most side (where you are supposed to press to release the door).
As I performed this bonehead move, I (of course) heard a snap.

The actual cup holder works fine in it's opening and closing, it's just the door I'm having the issue with.....It doesn't have it's normal, press and release to open the door function now.
Anyone have any tips on fixing/replacing the door parts?

 

As a general rule, the 'snap' sound does not denote goodness. And with this particular assembly, it is not a good sound. I fear you did what the previous owner did to my S55. The wood veneer attaches easily to the door piece, which is (unfortunately) an integral part of the box assembly. The 'snap' you heard was in all likelihood one of only two pins that guide the door up and down along the sides of the box. The dampening action is performed by the two arms that snap into the door piece. If you look carefully you can see how it works. One of the arms (RH, if I remember) is attached to the dampening/catch assembly while the other is attached to a more aggressive spring. You have probably broken one of the guide pins, but not snapped it completely off the assembly. This may explain why the door sort of works.

Through trial and error on my part, I have found no long-term repair of a broken pin. The engineering of this door assembly is not as robust as it could be and the two small plastic pins are, I think, the Achilles heel of the assembly. Replacing the door is the only long-term alternative.

You’d think MB would sell just the door, but nooooo... you have to buy the entire box assembly. The good news is I have been able to successfully replace the door assembly – using a fair amount of care – without tearing apart the entire center console. The trick is to be careful and work slow with minimal amount of pressure. The following procedure assumes one or both of the guide pins are broken, requiring the door to be replaced.

1) The wood veneer piece slides upward and slightly forward to disengage from the black plastic door. Use caution as you do not want to snap the plastic pieces on the veneer assembly. Replacement of this piece IS expensive, so be careful!

2) With the wood veneer removed, gently unsnap the each spring arm from the door. Again, use minimal strength to detach each arm. The top of the arms, where they snap into the door, is a weak design; not robust enough. The arms will want to spring downward - that's OK, let them.

3) At this point the door should be flopping freely and you should be able to easily see the two pins. Simply twist the door to disengage the pins from their respective guide grooves. Note how you twist the door to disengage; you’ll simply reverse the ‘twist’ direction upon reassembly.

4) If you’re smart, take this opportunity to clean the crap out of the grooves and the bottom of the box. I was shocked at what biological science projects were growing in the bottom, nooks and crannies of my assembly.

5) Remove the new door from your replacement assembly using the above steps.

6) Install the new door, reversing the steps above.

Wish I had better news for you, but the door probably requires replacement.

Cheers,
Jeff

 

MB- Dude,
Thanks for the in depth explanation. Very detailed.....
I am going to attempt it, but have to either find doner parts or order the new box assembly.....
Again, thank you for the 411.

 

You're welcome. More info is always better than less.
Cheers,
Jeff

 

You gave a great explanation on how to fix this and I just need to know how to buy a new door with unbroken slide pins. I have a 2003 S430. Any direction you could give would be greatly appreciated!

 

Quite interesting. Here is what my cup holder looks like and it is from the factory.

 

Is that aftermarket or factory ?

 

I believe it is factory. The receiving hole was only up to 2003. They are relatively rare and difficult to find.