Window Balancer Parts

I am confident we can help you replace these balances, but these stamp codes only refer to the calibration of the spring inside the balances. To know their identities, we need to see pictures of the nylon fittings or attachments at either end of the metal channel. From there, we'll do our best to narrow down what you need. 

This appears to be either a Series 380 or Series 385. The only difference between these two balances is the depth of the bottom nylon shoe, or the 'heel-to-toe' measurement. The image at the bottom of this post illustrates this dimension. Compare both with your old hardware to see what matches best.

Assuming that these are the same nylon fittings on each set of balances you need, once you determine what Series you're working with, you'll then need to determine the balance length. Measure the length of the metal channel, not including the nylon fittings, to do this. Finally, you'll then have to choose a stamp option, which is predicated upon those old stamp codes you gave us. That stamp code also generally indicates the length of the metal channel--it is usually 1" than the first two digits, but not always, so it's best to confirm to be sure. 

In short, I believe you'll need the following:

• (QTY 4) 31" balances with a stamp option of 3040
• (QTY 10) 31" balances with a stamp option of 3030
• (QTY 4) 28" balances with a stamp option of 2740
• (QTY 2) 16" balances with a stamp option of 1530

Comparison of the S378, S380 and S385 balance shoes.