MI Windows Series: 3540

Hello,

We do not suggest tilting the sash in while the sash is on the sill. Raise the sash about 6" before tilting it in to prevent the bottom corner of the sash from breaking.

We can't be sure of what you need with the hardware still installed, but the 15-087 coil housing pivot and 15-086 tandem coil housing would be a good place to start. These use the Series 180 coil springs. There should be a stamp code on the spring you'll use to choose the corresponding strength options. Thanks for posting! 

Series 180 coil balance diagram

Detail of 15-087

Detail of 15-086

Inside view of 15-086