107 Thermostat Question

[Don K]

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.