We have several windows where the channel balance top has broken out of the sash. These are Starline SL6000 series vinyl windows from ca 1999 with 1/2in nominal balances. Note that the balance top is secured with a screw into the sash.
Emily from SWISCO responded:
January 11, 2023
Hey there!
Your top sash guide may be a match for our 18-171 but I recommend you review our dimensions and compare them with yours to see if you agree.