Air suspension refers to air springs, and is a component that adjusts the height of the car body and softens impacts while driving, improving comfort while driving and reducing impacts on loaded cargo. The trailing arm uses the adjustment bolt as a fulcrum to transmit the impact that the wheel receives to the air suspension and absorbs the load in all directions caused by the rolling of the vehicle body, uneven driving due to the inclination of the road surface, and uneven road surface.

• Places where the impact load of the cargo is applied to the adjustment bolt fastening part of the trailing arm.
• Places where frequent retightening work is required due to looseness of the nut due to rough road conditions in the anti-loosening measures for the nylon nut.
• Places where there are many complaints from users and drastic measures to prevent loosening are required.

• The looseness of the nut has been eliminated, and the inspection cycle on the user side has been greatly extended.
• Excessive wear of the wear plate and breakage of parts can be prevented, and problems with the shock absorber due to loosening of the adjustment bolt have also been reduced, extending the life of each part.