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It appears you need a new coil balance system. That pivot shoe looks like it might be our 15-111. This shoe tends to use either our Series 160 1/2" thick Coil Balances, or our Series 165 3/8" thick springs. You'll need to remove your assembly and measure the spring thickness to confirm which you need. Watch the video below that shows how to remove and replace coil balance systems. Let me know if you have further questions.