yes, they are adjustable. You can crank them down tight for the full load handling, back them off when empty, or anything in between. I adjust mine to offset for the slide AND the crown of most back country roads I drive around here. You know; where the center of the road is higher than the shoulder making driving with a camper feel like you are walking with one leg longer than the other?
I keep my battery operated driver/drill with the deep socket sized to fit the nut in my truck with my jack.
BTW, I use BOTH air bags AND the overload springs. I use the air bags at around 30psi as a way to just take some of the weight off the shackles.