SACHS useful tip:
Installing shocks and dampers free from distortion

Improper assembly or accidents can lead to a distortion of shocks and dampers and later to serious component damage. ZF Aftermarket describes what to pay attention to during inspection and installation.

Distortion can severely reduce the service life of shocks and dampers. ZF Aftermarket explains the causes as well as the effects on the chassis component technology and suggests preventive solutions.

ZF Aftermarket names two main reasons for shock absorber/damper distortion: Firstly, even minor accidents may lead to the shocks' and dampers' mounting points being displaced so that they are no longer flush. Frequently, the piston rod is also bent in the process. Secondly, lack of care during installation is a frequent cause. When the axle is still suspended, the shocks and dampers must not be tightened firmly – the reason: Once the vehicle stands on the ground again, the mounting points are not properly aligned anymore either. The serious impact on the inner workings of the shock or damper is identical in both cases.

Due to the distortions, one side of the chromium plating on the piston rod surface presses against the guide and sealing unit with each stroke – and is ultimately worn through. Thisresults in strong wear on the seals and piston rod guide, mostly ending in a loss of oil and, thus, performance of the shock or damper.

To prevent the described distortions and defects, workshops should follow one simple rule: As a basic principle, shocks or dampers may only be tightened once the vehicle stands on its wheels – or when the wheels are pressed upwards with tools such as hydraulic jacks. Also, the specified tightening torque must be observed.

Last but not least, shocks and dampers installed under tension or a fastening nut tightened too firmly may lead to the pin joint tearing out. To prevent material overexpansion due to excessive tightening torques, it must be observed that, as a rule, no impact wrenches must be used when performing this work.

If these ZF Aftermarket tips are observed, shocks and dampers will function safely and reliably in the long term. This provides peace of mind for workshop customers too.