I use pliers on the upper clamp before ever trying to actually attach it to the coupler body... With proper tweaking you can get all six fingers of the cover to snap on tightly, then you put the clamp on the shaft, build the coupler & snap the clamp on, never trying to tighten it any further.. Cause every time I've tried to tighten it the damn thing winds up popping off.... So play with it off the car then leave it alone..