Tilt lock or balance
Thanks for reaching out to us! I am confident we have a replacement recommendation for the coil assembly you need. Although, to confirm the right replacements, I will need to see the assembly removed from the window.
In addition to the photo of the coil shoe, I'll need to know if there are any stamps/markings on your existing coils. If there aren't any, I'll need to know the exact weight of the window sash.
Please don't hesitate to reach out with any questions you might have.
Your coil balance assembly appears to be a discontinued Simonton pivot shoe. For this, we typically recommend our 15-192 Certainteed pivot shoe but you may need to shave down the aligners from the shoe to install it into the window. Take a look at the dimensions to confirm if it may work for you.
You should also be aware that the compatible pivot bar may be discontinued. That said, if you are able to reuse it, it should be compatible with the 15-192 Shoe. If you need to replace it, I suggest using the 26-336 Pivot Bar, but you'll need to shave down the rounded-color so that it will fit into the replacement shoe.
The 15-192 is compatible with the Series 170 Coil Balance as well as the Series 171 Coil Balance. The S171 is stacked on top of the S170 in situations where there is more than one coil. To confirm which coil strength you need, you'll need to look for any stamps/markings on the metal coil. If there are no stamps/markings, you'll need to get the window weight and divide it by the total number of coils in the window. The compatible cover is likely to be part 15-156 and the balance drum part 15-157.
I also wanted to make you aware of another option that could potentially work for your repairs. We are now recommending the 15-259 Coil Balance Pivot Shoe, which should fit will in the window track along with the Series 159 coils. To confirm the right replacement, you would use the same method described above.
You'll need the 15-256 to replace the cover. You would also need to replace the pivot bar with the 26-083 since your Simonton pivot bar wouldn't be compatible with the 15-259 shoe.
Take a look at the video below for a detailed explanation on this conversion.