Spiral balance replacement

Thanks for posting! I agree, you don't need to replace the whole windows. If they don't stay up, then the problem is likely with the spiral balance. Since you noted the diameter of the outer tube as 3/8", see our Series 900. We also have a helpful video on how you can install and charge these.

By plastic piece, are you referring to the pivot shoe? If so, you only need to replace it if it's broken. I don't know what you mean when you also refer to the piece on the window but the same rules apply: if it's not broken, you can reuse it.