Firstly, springs do not wear out. 2 things can happen to them as they age. They sag and/or break. Now I know that the earlies have a problem with rr spring breakage as I had it happen to my car.

Describing a ride harshness sounds like struts and/or strut mounts. Contours are well known for bushing problems both front and rear. At the front of the car check the end links, struts/mounts, sway bar bushings and especially the A arm bushings. At the rear check all the bushings including sway bar to subframe, trailing arm bushings at the body and the knuckle, struts/mounts, end link bushings, toe control arm bushings and the main lateral control arm bushings.

I'm sure if you go over the suspension as I've described you'll find the offending component(s).

Redcoat Raceworks. Performance parts and custom fabricating for Contours, Mystiques and Cougars. Specializing in chassis and suspension parts. Custom end links, control arms, strut tower bars, engine torque braces, etc.