Pivot bar twists
A quick learner from Philadelphia says:
November 12, 2012
Paul from SWISCO responded:
November 13, 2012
Thanks for posting. Did they only twist when you removed the sash? When tilting a sash in, you should make sure to raise it a few inches up first. This might prevent tilt bars from twisting. It's either that, or your pivot lock shoe is frozen and needs to be replaced. Test the cam of the pivot lock shoe to see if it moves or not.