I've had the Kore Blistein 7100 system on the '01 for about 3 years. Noticed a knocking in the rear the other day over bumps and examined the rear shocks yesterday. The left rear heims are lose. Not the mounting but the joints themselves. Probably about 2mm of play at each end. You can feel it and hear it. Right rear is OK. I would have thought such and expensive shock would last a little longer before maintenance. Performance is great but this is a little aggravating. I've also had a little (but noticable) play on the front upper mounts since new. Called Kent and he sent me a new heim joint for the front a while back, but it didn't help. The truck does get driven off pavement (forest service roads) about to 30+miles a week. Just wanted to see if this could be considered normal of if I should look for a problem.