Replacement window lift parts

I am afraid this is not enough information for us to make a determination on a replacement. If you have not done so already, you will need to remove the balance out of the window and attach some images for us to see. We will also need for you provide the tube diameter and indicate whether this balance is for a non-tilt or tilt window. 

Thanks, this is a huge help. If your spiral balance is 35" long and has a 3/8" diameter tube, then I recommend our S900-35. You will have to weigh your sash on a scale to confirm the best color tip option. It is definitely not black; no Series 900 balance was ever made with a black tip. If that's what yours looks like, then it has either de-colored from age or is covered in dirt. Weighing your sash will settle it for sure. We have a chart on the S900-35 store page that you can use as a reference.

For the pivot shoe, I recommend the 15-045. You may also find the 75-006 charging tool helpful for installation. 

If you don't have a pre-existing cutout on your window, then you'll likely have to make one. The video below should help clarify what I mean.

Awesome! That makes life a lot easier. In that case, I recommend the Green Tip option for the S900-35. Two balances with that option can carry 14 through 26 pounds, which easily covers your sash weight.