Hey there!
Thank you for your patience during our busy season. Take a look at our 15-087 pivot shoe, which uses the Series 180 coil balances and compare our dimensions to yours to see if this matches what you need. I've also attached some videos below that you might find helpful.
Your coil springs can lose their strength over the years and can wear out from constant use, which makes them prone to breaking or snapping. You can use silicone spray if you want to lubricate. It will keep the track clean, whereas an oil-based lubricant would catch dirt. If your coil housing is undamaged you can reuse it, but if you need a new one see our 15-086. All orders can be placed directly on our website at your convenience as well!
It looks like your coil might have the number "4" on it, but I suggest weighing your sash on a scale just to be 100% sure you choose the appropriate spring weight. Get back to me with the exact sash weight and we can work it out from there.
Thank you! Since you have (2) coils on each side of the window, you'll need a total of (4) S180-4 coil balances. Two of these on each side of the window will support a sash weight of 16 pounds.
My apologies. Yes! You can use (1) S180-8 on each side, which would support a sash weight of 16 pounds.