The balance will not hold the window up, but I think it was capable in the past - just has worn out.
Based on the information I provided, can you tell me the parts you recommend for replacement? I've attached 5 photos.
Thanks.


Great, thank you for the additional information. Now, it looks like this balance is similar to our Series 770 channel balance. Check it out and let me know if you agree. If so, we can make what you need, but they will have to be custom built to accommodate that weight.
Before we get started, though, I just want to let you know that there are a few options. If you are replacing the 32" balance, I recommend either our 32G option, or 32H option. Two balances with 32G can support a sash weight range of 37 through 40 pounds, while 32H can support 40 through 43 pounds. Take a look and see which is better.
If you want to replace the 28" balance, though, then I would go with either our 28G option (36 through 40 pounds) or our 28H option (40 through 43).
Let us know what you decide and we can go from there.
The G and H options are not standard, so I'll go ahead and email you a purchase link and price quote for your review. Please let us know if you have any questions!
As for the shoe, since yours is 9/16", I would consider our 15-129, which has the same thickness.