Metal cams broke in coil balance

Hello! Your coil balance appears to be a match for our S140-12. Look it over and see if you agree. I also recommend that you check if your sash weighs 23 through 24.99 pounds, just to be safe. That is the operational capacity for this balance.

As for the pivot bar, that'd be either the 26-398 or 26-405, depending on hole placement. We have detailed measurements on each pivot bar's store page that you can use as a reference.

As for removing the balance from the window, it is possible but very difficult. What I do is use a slotted screwdriver to pry it out. The goal is to kind of leverage the opening a little wider, then "feed" the balance assembly out. In other words the bottom end sticks out and then you pull the whole thing out through that hole.

That makes it sound easier than it is, though. I'm not going to lie to you: it's very frustrating, even for someone who has done it a million times like me, but that's the way it has to be done. You can try to make the cutout larger, but then you run the risk of the balance falling out during normal operation. That's the last thing you want, so just use your best judgment.

Yes, that's exactly right. All coil balances work under that principle. The coil springs are held in a plastic cartridge and connect to what's called a pivot shoe, which is what connects the assembly to the sash. You can see detailed photos of the Series 140 on the store page I linked to in my previous response.