Searching for Simimngton window balance upgrade

Hello there. Could you show us a picture of the Simonton coil balances you're looking to replace, preferably removed from the window if possible? The pivot shoe they connect to would be especially helpful to see--the shoe is the part further down the window track that the coil springs connect to, and also from which the window sash pivots. Simonton windows can use a few different coil balances, so identifying these parts would help us narrow down your options.  

That will suffice, thank you. The closest match we have to this pivot shoe is the Certainteed 15-192. It's quite similar, but the Certainteed version of this shoe has alignment 'nubs' on its face that your old shoe lacks, and we've had customers report this prevents the Certainteed shoe from working in a Simonton window. You could rub the nubs down so that the shoe fits properly, but I can't guarantee this would work (also note modified items cannot be returned for refunds). 

Another possibility would be to replace this entire coil balance system with a capable substitute. We potentially have just that with our 15-259 and Series 159 Coil Balances. We've tested using this setup to replace old Simonton coil systems and it seems to work. The video below explains how to do this in detail. Note that you'd have to replace the assemblies on both sides of the window for this to work. 

Note that when tilting a window sash to clean or remove it it's always important to raise the sash a few inches first, to give the shoe clearance for the tilting--otherwise they can break. That said, the 15-192 design seems quite delicate to begin with, so I'm not surprised you've had trouble with it. Let me know if either of these options work for you, or if you have any other questions.