The damper is basically a shock absorber, which is mounted between the drag link and sub-frame. It's function is to dampen the impact of lateral movement of the front suspension. If you feel the steering wheel move left/right with each and every minor imperfection of the road surface, chances are the damper is shot.
Mine, when I replaced it, appeared to be an original unit. When I pulled it, it had no absorbing ability left in it. I felt zero resistance when pulling the shaft out, or trying to push it in. The replacement (ordered through PartsShop) required a good amount of effort to push, or pull, the shaft and the wheel felt much firmer and more stable after replacement.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.