Casement window crank mechanism

Quick Learner from MA

Jul 22, 2026 10:22 am

Will crank out but slips when trying to crank closed.
note picture is from left window which works fine. Trouble window is the left window

1 user uploaded image

4 Replies

Bob from SWISCO

Jul 23, 2026 1:47 pm

Thanks for posting. Please compare to the 39-188 Dyad Operator. See if this matches what you have. For a handle, see the 39-114L.

Alternate measurement of arm

Quick Learner from MA

Jul 23, 2026 2:58 pm

The arm is about 4.5 inhes long rahter than 5 inches as how shown in picture but all else looks identical. Is the 5 inch a rough measurement?

Bob from SWISCO

Jul 24, 2026 12:10 pm

The 5" is an exact measurement. We've seen versions of this operator with a shorter arm from time to time. Unfortunately we don't carry a version of the 39-187 and 39-188 with a shorter link arm. We're not sure if it even is available anywhere. You do have a few options to make this work though. You could try installing the replacement as is to see if it works. Next, you could try repositioning the stud bracket to make up the difference. If all else fails, you'll have to swap the new and old operator link arm. You'd have to drill out the new and old arm and use the 62-014B rivet. To install this rivet, you'll have to hammer it in; I recommend doing it over a metal plate if you have one.