Unknown part, possible linkage

[junker68]

Hi,

I was preparing to replace my glow plugs in my 1987 300sdl. As I was poking around, I noticed a part which looks like it's missing a linkage.
If you look at the photo, the part in question is just below the very center of the photo. It is located next to the red marked black plastic piece.

The question, what is the part and is any linkage missing? The ball on top of the part does move/rotate.

I couldn't attach the photo, so here's the link to the photo.

http://library-static.snapfish.com/library/share?w=snapfish_us&c=snapfish&l=en_US#4wfZXy_a60D4X2MxQT1zvw/AUS/27938661414/SNAPFISH

Thanks!