An excavator can have a good engine and strong hydraulics but still require major spending if the undercarriage is heavily worn. Before buying a used excavator, inspect the complete track system rather than looking only at the track shoes. Links, pins, bushings, rollers, carrier rollers, idlers, sprockets and track tension all work together, and wear in one area can accelerate wear elsewhere. Start with a visual inspection of both sides. Look for uneven wear, damaged shoes, loose bolts, leaking rollers, worn sprocket teeth and abnormal track position. Then operate the excavator and check travel, noise and track movement. For a ...