Window crank

Thanks for writing. We've seen this difference come up before. Your best bet is to consider replacing your old track connected to the window sash with our 39-505. This is compatible with the 39-031's roller and should solve any potential problems. Take a look and see if you think this track could attach to your sash. 

Profile view of 39-505

Thanks for getting back to us. I see what you mean about the position of the track in relation to the sash. The problem is that we don't have an operator in this style with that steel wheel. In some cases you might have the clearance underneath the sill cover in your window, so my hope is that you would have room for the 39-505 so as to accommodate the new style operator, but it's of course not a guarantee. It will be a gamble.

Another thought would be to remove your steel wheel from the old operator and install it on the end of the 39-031. This could be a little tricky, though. They're not easy to remove and swap around like that, but if you're handy then it may be an easier solution.

Lastly, take a look at the 39-365 single arm operator. This has a steel wheel, same as your original and might just work in your situation, plus it takes the same track you now have. However it will almost certainly take some clever adaptation since it only has one arm. 

Ultimately, you may want to seek the help of a local professional if these kinds of adaptations aren't something you've done before. This could quickly turn into a Project, with a capital P.