Double hung window track

Hello there. I can see what the problem is. The pivot shoe broke. The pivot shoe is the plastic block with the metal cam from which the window sash can tilt. The shoe also connects to the coil balances further up the sash--the coil springs are the tension mechanisms that regulate the window's movement. 

Sometimes pivot shoes break from age. However they can also break if you do not raise the sash a few inches before tilting it inward. 

Your pivot shoe looks like our 15-177, which works with Series 152 Coil Balances. Take a look and let me know if you have further questions.

Alternate image for 15-177

If the shoe is the only part that's broken, then you can get away with just replacing that, yes. No reason not to reuse your coil springs if they're in good working condition.

However you should note that two balance assemblies in the same window should be identical. It would be very odd for one side to be different from the other.

Great! I'm glad you find our system to be helpful.

Since this is the same window, you would still be using our Series 152 coil spring. Even though only one spring on this side is broken, you should still replace both just to be safe.

We don't sell the old style covers, unfortunately, but we sell the modern style that are made now. This is split up into three separate components designed to snap together: see our 15-143 bushing, 15-144 bushing cap, and 15-145 barrel.