During my ham fisted f'up up my chain slipper I noticed that the drive gear to the oil pump and PS pump is not keyed. The timing sprocket is however. I beleive this is to help protect the crank should a lockup failure at either of those pumps happen and the gear simply spins. Obviously if enough slipping happens the bushing behind the gear will be toast.
Get that crank bolt torqued!
Get that crank bolt torqued!