Take a small mirror and look from behind the crank handle. I'm thinking of various door handles that I have removed in the past.
Maybe it has a set screw or a retaining ring that fits into a groove on a splined shaft.
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Vent Window Crank.jpg (28.8 KB, 117 downloads)

Last edited by buoymaker; 09/23/2021 2:26 AM.
"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."