HPF Regulator Switch Unit Screw, W116 6.9 and W126 with 4 corner HPF
This screw is located on top of the HPF regulator aluminum block ist mounting the cam disk to the aluminum block . If the original screw is damaged or broken it can be replaced. Often time the old broken off thread need to be drilled out carefully.
If this work is too much for a DIY mechanic our repair shop at www.600airsuspension.com is offering renovation of the switch unit.