andersen sash balance J18 5 23 7-77

Hi,
I need an andersen sash balance, my numbers are J18 5 23 7-77. I was assuming I needed the 523 balancer, however the picture of the new balancer does not show screw holes through the balancer like the picture of old balancer has, I need these screw holes. Does the balancer come with the 2 screw holes through the balancer? I can take picture if needed.

thanks for your help,
Geoff

Hi Mike,
Thanks for your reply. My concern is that the balancers I took out has 2 screws in the middle of the balancer, one of the screws is used to attach the top sash liner the other screw is screwed in under the top sash liner. The balancer 24-531 does not appear to have these screw holes.

I attached a picture to help visualize, one of the balancers is up, the other down (show both sides).

Do these new balancers have the screw holes to reflect where the old ones are?

thanks,
Geoff

Thanks Mike,
I assume then that I would need to make new holes in the top sash liner to fit these (as they are not aligned with the current balancer holes) or order a new top sash liner for the new screw hole placements? Is this what is normally done?
Also, does Swisco sell new sash liners for the Andersen Narroline Window?