Don't know if they compress or just get dry rot with age. Probably compress, though. Honestly I won't know exactly what is the cause as I am replacing both strut mounts, shocks & dog bones (pitman arms). All are toast on mine, I'm sure. Pretty sure my springs are original as well, and that's the one thing that I am not doing, as I am not lowering the car. When all's completed, if it still sags, then I guess I'll know that springs were necessary as well.Originally Posted by Morgenster