omg, wish I'd watched this first. I was just cleaning the bottom window, had it inside, resting on a chair, went to get more window cleaner from the kitchen and when I came back, my big cat was laying on the window in the sun....she had finger printed up the total half of the window...got her down but the weight of her, slightly tilted the window, so when I went to close it, it came crashing out, smashing into the woodwork, etc. Then they are so very heavy, had my husband 80, try to reinstall it, and I didn't know if we had to get both sides into the groove or clutch as you call it, we only got in it right side, it all closed up ok but I'm afraid it might come slamming down on us, it appears to be fine, tho. I could tell by your picture that it was only in right sash. Clutch.