The "Gorilla Knob" was the control knob for the glow system and the fuel on and off on W115 and older MB diesels. At least both our W115 and W121 had them. They were used in conjunction with an extra glow element mounted on the dash behind a chrome plated cover with holes in it like a "salt shaker" top. The last item in the old system was the twist knob for idle speed adjust also located on the dash below the instrument panel.

These were all originally the old series glow plug systems with the heavy bare wires that ran between each glow plug to provide enough extra resistance that 4 ~2v glow plugs could survive on 12 volts. Of course the glow element behind the salt shaker also provided some voltage drop, so maybe 4.5 glow plugs.

As noted above the "Gorilla Knob" provided a Positive fuel cut-off and there were no concerns about the vacuum status when shutting off the engine. The nick-name for the Knob came about because it took some arm strength to pull against the spring, especially in below freezing temps where it needed to be held for long periods of time.

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150