Replacing constant force spring assembly

Thanks for posting. I'm afraid the Series 140 isn't the right replacement for your window, as it has a different thickness and width compared to your old pivot shoe; this will adversely affect window function. You can view our Return Policy here. I believe you have our 15-087 Coil Shoe, which works with the 15-086 Tandem Housing and 16-04 Housing Bracket. This system uses our Series 180 Coil Springs, which are sold separately. If your window sash weighs exactly 30 lbs, then you'll need (1) of the S180-7 7 lb spring and (1) of the S180-8 8 lb spring on both sides of the window sash. This would equal 15 lbs of support on either side of the sash, for a total of 30 lbs of support overall. 

As far as your pivot bar goes, we don't have an exact match for this pivot bar, but I believe the 26-089 may work as a substitute. Just go over the dimensions, particularly the distance between the mounting hole(s) and the tip of the pivot bar that inserts into the pivot shoe, to confirm this will work for you. Let us know if you have any other questions.