The newly rebuilt actuator and model 91 amp were installed and tested and to my dismay no combination (old act. /mod.79, reb. act./mod.79, old act./mod 91, reb. act. mod.91) will cure the low speed surging. At speeds above 50, I'm not sure if I can notice it or not. I will convince myself that it is not there and just deal with it as is. I think this is as good as it gets.
Overall I guess I am happy with it, after all, the cruise control does work well. I think maybe I expected it to work better than it was designed to. Most vehicles with cruise require 35 or 40mph for engagement and maybe the reason is my situation. Who knows, maybe it will 'break in'; stranger things have happened.
GDL has my highest regard and I encourage any of you ready to tackle your cruise to start with them.
1982 Mercedes-Benz 300CD
1982 Mercedes-Benz 240D - stick