Need replacement window balance

Handy Person from California

Jul 19, 2025 8:34 pm

Windows are from around the '80s, non-tilt out, one side gave out and slid down in the frame so I pulled it out. Looks like one of the pulleys broke a rivet?
ID printed on channel – 28 4 GX CMC 11. The metal channel measures 29" long.
This has happened before to a couple of the other windows and we had to order the part but replaced myself. Came across your website to see if I can order through you guys and get a cost.

5 user uploaded images

6 Replies

Bob from SWISCO

Jul 20, 2025 1:49 pm

Hello there. I am confident we can help, but can you show us photos of the 'guts' or underside of the metal channel? Some of these balances from the west coast have a special design we must account for. Once we see whether or not that is the case here we can proceed.

Handy Person from California

Jul 20, 2025 7:23 pm

Hi Bob,
Thanks for the response on my question. Here are more photos of "inside" the metal channel. Hopefully these wil cover what you need.
Thanks,
Kevin

4 user uploaded images

Bob from SWISCO

Jul 20, 2025 8:17 pm

Thanks for getting back to me. It seems to me you have either an S351-29 or S390-29. The only difference between these two channel balance is the depth of the bottom nylon shoe. See below. Measure your old balance's shoe depth to see what matches best. For a stamp option choose 2840.

Comparison of the S351 and S390 balance shoes.

Handy Person from California

Jul 21, 2025 10:20 am

This is great! So mine is measuring 1 1/8". I'll go ahead and order two of the S390-29 (stamp 2840). Thank you so uch for the help on this!
Separate question – If the window starts to get harder to open is that a sign of the channel balance getting worn is needing replacement?
-Kevin

Bob from SWISCO

Jul 21, 2025 3:05 pm

Hey Kevin. Yes that can definitely be a sign of channel balances wearing out, and if one pair fails usually other windows aren't far behind, since all this hardware was likely installed at the same time.