My window won't crank open or close due to crank handle"slipping". My plastic cover also broken. The part of crank that fits into mechanism appears stripped.

Hi there, thanks for writing in. In cases like this where the gears have been stripped, it is unfortunately not possible to replace just the handle. In this situation the whole operator would need to be replaced. I would be happy to assist you in identifying the correct operator. However, in order to do so I will need to see the arms of your operator from a birds eye perspective. Thanks! 

Take a look at our 39-035 and 39-036. Look over their dimensions and see if you could use these as replacements.