Not sure how these work

Question

I have 4 windows that have this style regulator. The white item with 2 screws is new to me. There are letters from A-F on the sides and the #2.  All the other windows have spiral type. I am not familiar with what I have. Do you recognize this style. I'm afraid to unscrew the part, in case it's under tension. Looks like I'll need some pivot lock shoes as well.

Bob · Accepted Answer

This Pivot Shoe looks like our 15-175, which uses our Series 152 Coil Springs. Those springs are what are inside that housing support in your photos. If the support itself is undamaged, you could reuse it; otherwise, we use a different support system with these springs: the 15-143 Bushing, the 15-144 Bushing Cap, and the 15-145 Support Barrel sandwich around each spring in question. The video below shows how to replace multi-spring balance systems. While a different Series, the principles are the same.