Are you having problems with a rough ride?? Sometimes over the years the springs can get in pretty rough shape.. With the springs working over the years they will cut into and wear a ridge in the spring below each other.. Then when the spring really needs to 'spring' it can't as the spring can't work past the ridge.. Plus these things can get all rusty and 'sticky'.. Many times they can be pulled apart and cleaned and ground smooth.. Put them back together with a little oil or grease on each leaf and they'll ride like new,, well,, almost like new..