After about how many miles should you consider replacing the shocks?. Just wondering because my roadmaster sedan has what I am sure are the original shocks, standard FE1 suspension no load leveling in rear. The car currently is just under 68,000 miles it does not bounce uncontrollably or bottom out and when my mechanic friend had it in the air none of them appear to be leaking. Just wanted to know when to consider replacement. By the way should the springs be replaced as well?