There's a position to 'the back or down @ 5-4 oclock' the shackles want to be 'stationary' so that when the car lift/hooks the shackles end up vertical or straight up and down, it's all in the chassis book...
When your car lifts, the angle to the front only gets worse, and they don't move like they should because there is no give, hence a 11 sec toads shackle resting on the frame...
ha ha ha get it now, no more riddles lol