2710 Series Arm Replacements

This product is called a channel balance. I'm confident that we have a replacement for this but I'm not sure what you have based on these photos. 

In order to figure out what Series this is, I need you to remove an undamaged version of this balance from the window and show me clear pictures of the top and bottom nylon fittings. I will also need to know the dimensions of these fittings.

Thanks, these photos are a huge help. Just note that I can't garner precise size from a photo of a tape measure, but we have reference photos that should help you determine the right size.

Based on what I see here, you have either our Series 351 or Series 390, depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match. Do also make sure to measure the metal channel before you buy anything to verify the proper length. Your original post mentioned a 2710 stamp with a 37" metal channel, which is irregular. A 2710 stamp balance should have a 28" long metal channel.

Comparison of the S351 and S390 balance shoes.

Thanks for verifying. You don't want to measure the overall height of the window, or the entire length of the balance. You only measure the metal channel; ignore the plastic fittings when determining length.

If your stamp is "2710" then the length of the metal channel should be 28". I also see in one of your photos above that you have a balance with a "15 5" stamp. Is this a different assembly? A balance with a "15 5" stamp would have a 16" long metal channel.

Regarding the shoe depth, 1-1/16" means that it probably wore down from use over the years. It happens all the time. It was likely 1-1/8" when it was brand new, which makes this our Series 390.

Great, glad to hear that our balance was a match.

Regarding the top sash guide, I'd be happy to look into that. The Series 390 is compatible with many, many different guides though. We need a photo of an undamaged version of the original, ideally removed from the frame.