Replacing thermostat on my 1985 500SL. This thermostat has a small arm that extends to one side with a vertical "pin" attached. The pin moves up and down in a recess in the housing. My question is what is the purpose of this arm and pin ? My Mercedes mechanic says that whenever they install one of these that they cut the pin off. He says that this pin can acutally bind or rub after a while and cause erractic opening/closing of the thermostat. I'm assuming the good German engineers had some purpose in mind for this feature.

Your tech is correct... MB mis-designed that part!

Cut the arm off & install like any other t-stat.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

interesting info. thanks.

__________________
Ben
1987 190d 2.5Turbo