Double Hung Window Balance

Hello,

We can't be sure with the hardware still installed but the shoe resembles the 15-180, which uses the S190 coil springs. You'll need to locate the numbers stamped on the original coils to choose the corresponding strength options. These coils use the 15-181 support and 15-182 bushings for installation. Take a look at these parts, as well as the related videos and return policy here. Thank you! 

Alternate image for 15-180

I agree that it seems like you've picked out the correct parts besides one of your coils appears to be stamped with a 9. Since it can be tough to determine if the stamp should reach 6 or 9, I'd recommend weighing the window sash. From there, you can divide the weight by the number of coils on both sides of the window, 4 in your case, to confirm the correct strength options. You are also correct that you should be able to reuse the original supports and bushings if they are still in good condition. 

As for the sash lock and keeper, take a look and compare the specifications of the 90-309 lock and 90-307 keeper to yours. We also offer the 90-308 opposite-handed version of the lock. Just let us know if you have any other questions. 

Alternate image for 90-309

Alternate image for 90-307

You're correct that for a window that uses one 8-pound coil spring on each side, the sash would generally weigh 16 pounds. For a 26-pound sash, I would recommend using one S190-640 and S190-740 on each side of the sash. Just let us know if you have any other questions.