Tip: what is the purpose of the groove adjustment on the shock absorber?

A frequent question relates to the purpose of the so-called groove adjustment, which can be found on some series shock absorbers as well as the BILSTEIN models B4 / B6 / B8. This specifically concerns the grooves for the snap ring of the spring plate. First of all: this has nothing to do with a freely selectable height adjustment à la coilover suspension in the OE area and in series replacement, even if such solutions exist in the tuning and off-road retrofit segment.

Groove adjustment shock absorber

But what are the grooves for? Most series vehicles have different equipment and engines and thus different axle loads, which require corresponding vehicle heights. The different grooves are then required in order to be able to define the correct body height with the variable spring plate. Correspondingly, this option is also available with the standard replacement shock absorbers from BILSTEIN. Alexander Kranz, employee of the BILSTEIN Academy explains: “During assembly, the spring plate heights, or the correct position of the snap ring and spring plate, must be set exactly according to the functional dimensions of the existing original part.

The grooves are therefore not used to lower or raise the height at your own discretion. ”In simple terms: where the snap ring was on the removed shock absorber, the new snap ring must also be mounted on the new shock absorber. If this is not observed, deviations in the height of the spring plate upwards or downwards can lead to problems with the preload. During compression, there is now a risk, among other things, that the spring will block or that the support bearings will be destroyed. When rebounding, the locking package, piston rod, support bearing or vehicle dome can be damaged.

Important points during assembly:

• Pay attention to the correct position and assembly of the snap ring
• Make sure that the snap ring is correctly seated in the groove
• If the snap ring is not properly seated, the entire spring plate will slide down
• Pay attention to the installation position / orientation of the spring plate: do not interchange the top and bottom