Replacement spring rial for vertical sliding window, "Unique 31-C-30"

Question

Hello, recently we've had two of our 4 rear windows have their vertical spring loaded rails pop out the top and we can't keep them up anymore. I've removed one set of rails and found the upper spring mounting bar is shearing the metal rail itself and the lower pully broke away from the bottom mounting bar. This happened with a second window also. I'm hoping i could find/buy two replacement rails with pulleys. The springs are still good but if i need to buy it as a full rail set i will.

The channel width is 9/16" wide, the metal channel is 31 7/8" long, and the bottom fitting is 1 1/8" deep.Please help. Thank you.

Jasmine · Accepted Answer

Thanks for writing in! It looks like you have the S390-31 with a 1-1/8" shoe. These balances have a wingless top and bottom attachment.

To confirm that this is the correct series channel balance needed for your window, look over the dimensions from the diagram below to double check the depth of your bottom shoe.

You'll need to select the 3130 stamp.

Comparison of the S351 and S390 balance shoes.