Piston Rod Damage

While installing a shock absorber, strut or cartridge, it is often difficult to prevent the piston rod from rotating when tightening the top mounting nut. KYB piston rods have been designed to allow for a Spanner (Figure 1), Hex Key (Figure 2) or Key Way (Figure 3) to hold the piston rod in position during fitment. The Key Way design locks the piston rod in the top hat mounting assembly preventing the piston rod from rotating.

Every KYB piston rod is hard chromed to ensure a completely smooth surface guaranteeing perfect metal to seal contact. However, sometimes fitters use pliers, multi- grip or vice-grip type tools to clamp the piston rod while tightening the top mounting nut. This results in the piston rod becoming burred and scored by the teeth of the tool biting into it; consequently once the piston rod starts to compress and extend while in the vehicle, the burs quickly cut through the oil seal resulting in leakage. The suspension item is now damaged and not performing at its optimum level and needs to be replaced.

**What must be noted is that KYB do not cover incorrectly installed suspension products under warranty. The suspension item failed, not because of a faulty product, but due to incorrect installation.