Constant force Balance S140-?

Thanks for posting. The Series 140 Coil Balance system is compatible with a number of different pivot bars. The only way to know what works with your windows in to show us pictures of the old pivot bar removed from the window for a closer look. Speaking of which, I'd like to see pictures of your old coil balance system, including the pivot shoe and the coil housing, just to be absolutely certain we know what you're working with--the Series 140 looks like a lot of other, different systems at first glance, so I'd like to make sure we identify this correctly for you. The video below shows how to remove and replace coil balance assemblies. Take a look. 

Thank you. This is not the Series 140 you have here. Your assembly is actually discontinued and no longer made.

The good news is that we have hardware that will work for you, and without having to change your pivot bar, either. See our 15-177 pivot shoe and Series 152 coil spring. The 15-177 shoe looks a little different than yours but it was specifically designed to replace the original and should work perfectly well without issue.

We don't sell the plastic cover that goes over the spring, but as long as the original is undamaged then it can be reused. If not, let me know and we can look into other options.