22 yr old windows that need balances..

Question

These tilt-in vinyl windows were installed by Pulte in 2001 in North Carolina. They appear to be Block and tackle style but instead of pulleys, the string wraps around nylon blocks with curved tracks for the string. The nylon blocks run up and down on a center rod that sits in the channel. One of the blocks is attached to a spring which runs to the shoe and is attached there as well. The other is the one that slides up the pole, taking up slack as the window lifts.

The shoe is a T-style (it needs to twist to get it into the channel) but isn't a locking style. The tilt out window just has a cylindrical pin with a slight head on it and fits into a forgiving slot (1/2" tall) in the shoe )presumable to make setting it in place easier). it is not a squared off pin that could turn the cam of a locking style T. Back when they weren't all busted, I don't remember the shoes springing up as soon as the windows were removed. I thought they stayed in place but I can't be 100% sure. I do know there's no locking mechanism on the shoe.

The entire construct sits inside a channel that is part of the window itself and does not have a separate channel as all of the block and tackles online seem to.

Sadly, short of some patent numbers, there aren't any markings aside from a NAMI certification sticker. I expect it's boilerplate but it reads:
Code: PAT
Spec: NFRC
Series: 1100/1200 SH
MST: 4060
PAT-M-021

I'm thinking I could swap in a spiral balance more easily than a block and tackle that has a channel already. but that seems to require a locking shoe, which seems to require a new pin in the window, which would require figuring out if the screw hole lines up.. etc.. So I was wondering if a more direct replacement exists.

The T-shoe is black nylon, and 15/16th at its widest. It's 1 and 1/2" tall and a half inch deep. The channel seems to be 1 and 1/16 or 1/8th wide with the lip providing only a 9/16" opening. The channel is 9/16" deep. There are no openings along the channel for a shoe to slide in (hence, the T-shoe).

Jasmine · Accepted Answer

Thanks for posting. It appears you have an old crossbow balance which has been discontinued. However, I am confident our Series 795 Channel Balances may work for you. To start, you'll need to confirm the length of an undamaged balance as well as if the channel of the balance measures 1/2" in diameter. If it is not 1/2" please let me know.

These balances are used with T-Lock Pivot shoes that do have a pivoting cam. Since yours measures 15/16", you'd need the 15-194 shoe.

You'll also need to confirm the exact weight of the sash to determine the weight range your balances should be able to carry. I'll so need to see the clip at the top of the balance.

Take a look at the video below for details on the information we'll need from you to confirm the correct replacements.