I was looking for a decent video but only saw this quickly.
but basically the lifter rides on the cam lobe and pushes the back of the rocker arm up, which pushes the front down. the spring pressure then pushes the opposite way to follow the down side of the lobe. if the valve is stuck down the spring can't come up and close the valve. when I lifter gets stuck it doesn't open the valve.
I don't know if that makes sense haha. but both are needed but kinda the exact opposite of each other. you'll have to figure out which side is causing the slop.
but basically the lifter rides on the cam lobe and pushes the back of the rocker arm up, which pushes the front down. the spring pressure then pushes the opposite way to follow the down side of the lobe. if the valve is stuck down the spring can't come up and close the valve. when I lifter gets stuck it doesn't open the valve.
I don't know if that makes sense haha. but both are needed but kinda the exact opposite of each other. you'll have to figure out which side is causing the slop.