
Originally Posted by
oj88
The spring is the one bearing the weight of the car. If the ride height becomes too low when you put passengers in (with the car parked), the springs may have sagged and probably needs replacing. This is normal because they wear out and sag over time. Some springs, even on the same car, wear down faster than the others, most likely due to imbalanced loading of the car throughout its life. That's why you see some 10-20 year old or older cars with uneven ride height from left to right or front to rear. This is aside those cars who encountered an accident that put their suspension out of whack.
The work of the shock absorbers or dampers is not to carry the weight of the car, per se, but to dampen the tendency of the spring to bounce. So if you find your car bouncy, the dampers may need replacing as well.
Now, if you combine the two factors (sagging spring + worn-out damper), you'll be hitting the bump-stops (or your tires touching the fender liners) more often when you fill the car to capacity, even on a relatively level road.