Noise when raising and lowering window

Thanks for writing in, and sorry to hear you've had trouble with your new S351-35 balances. It's best to start from scratch to make sure these were indeed the right balances. If you still have the original balances, that would be a big help in this process.

• First, you say you chose a stamp option of 3430. This supports a window sash in the weight range of 18 through 23 lbs. Please confirm that A) your window sash's exact weight falls in that range, and B) the old stamp on your original balances.
• Next, we need to make sure the S351-35 was indeed the right balance. Can you confirm the length of the metal channel on the original balances, not including the nylon fittings on either end? Can you also show us pictures of both of those nylon fittings? 

From here, we'll do our best to help you identify the issue. Thanks.

Thanks for posting. The difference between the nylon fittings you're showing me here shouldn't be an issue. Yours is an older style, but ours still works the same way. It's important to note, however, that you're showing me the top nylon fittings, not bottom. You mentioned in your post that the pictures are of the lower nylon fittings. I want to make sure you aren't installing these balances upside down.

Can you confirm that the bottom fittings are the same size? The depth has to be the same, not just the style. Can you also confirm that your old stamp read 3430 and not something else? When using the new balances, did they leave a scratch mark on the window track? Finally, is the window aluminum or vinyl?