The top nut holding the piston rod and the upper mount on top of the shock absorber plays a very important role. (Photo 1)

If the top nut is properly tightened, you may hear unusual clattering noises while driving. In some extreme cases, there is the possibility that the shock absorber and/or the vehicle may suffer damage. For these reasons, it is very important that the top nut be firmly tightened at the appropriate torque. When tightening, please use a torque wrench to hold the nut so the piston rod in the shock absorber does not move. (Photo 2)

For damping force adjustable shock absorbers, over tightening the top nut will apply too much pressure onto the piston rod top, and there will be a possibility the piston rod will be deformed or damaged. If deformed, the damping force adjustable mechanism will cease to function.

To prevent this from happening, tighten the top nut at the appropriate torque before installing into your vehicle. If you use tools that are not of appropriate size to hold the piston rod, it may also result in damage. Also be very careful with the flat surfaced part (sliced part) on the piston rod threading, because if you under estimate it you may damage the threading.

If the piston rod becomes damaged and the damping force adjustable mechanism fails to work, the piston rod will need to be overhauled.