coil balance # 18 (photo match)
Could we have you upload photos of the coil spring system in question? We will take a look over and get back to with some recommendations on a replacement.
I also encourage you to look over the coil springs we offer here.
i will have to wait for my daughter to do photos. your spring #180 looks like mine - it is about 40 inches long 7/16 inches wide - one of the slides where the bottom of the window (pin) sits in has a mark 8r the other side 8l - my spring also has two holes one end only (top end)- the widows are reliabilt - by survivor technologies, inc. model #7100 - built about 2002.
the end of coil spring just pushes into the piece the window connects to, it goes in about 20 inches.
Thank you for the additional information. If the coil spring is 7/16" thick, then I believe our Series 180, which happens to be 15/32" thick, could be a strong possibility for consideration. We will need to see the spring and pivot to give the ultimate confirmation. So far, I think you are on the right track.
thank you