The crank will not close the window.
The gears skip when the window is almost shut
Dave Sr. from SWISCO responded:
November 13, 2014
Looks like you have an older version of our 39-099. Andersen states this is the replacement for the #1521101. Take a look and see how well the dimensions match. Also be sure to check if you need to use the 39-362 adapter plate.