July 2013: How It’s Made


KYB’s OEA Piston & Valves

Damping valves are the heart and soul of a shock or strut. In a twin tube there’s two sets; one in the piston and one in the base valve. The combination of fluid passages and various size valve discs are how a shock is calibrated. All of KYB‘s manufacturing and assembly processes are the same for OEM (new vehicles) and aftermarket products (Original Equipment for the Aftermarket). The only difference is in the damping valves: KYB’s Excel-G shocks and struts are calibrated to help restore the vehicle’s designed performance, not alter it.


There are hundreds of similar but slightly different valve discs to choose from so a sorting machine selects, measures and stacks the individual pieces that will be used during assembly.


The KYB assembly area clean rooms look like what you would expect at a NASA facility. Anyone entering must go through two compartments to be air-blown off and then into a de-pressurizing chamber to remove any lint or hair.

DSC_0167Small DSC_0172Small DSC_0151-2small

Assembly begins with the piston body. A Teflon piston band is heated to make it expand, then placed and bonded to the piston body as it passes along an automated conveyer. Air is then blown onto the assembly to quickly cool it down.

15Small  ValveAssemblySmallv2

Each shock or strut part number has a unique calibration and set of valve discs. Shims, leaf discs and notched leaf discs are final cleaned and moved to an assembly technician to be placed inside the piston valve. The base valves are assembled in the same way and then a retaining nut is torqued into place with a pneumatic tool. The assembled piston valves then move to a separate area where they will be attached to the piston shaft and base valves welded into working cylinders.Along the way, laser beams and other measuring devices will check to be 100% certain that all components match perfectly. Every step of the process has a pass/fail.

That’s one of the reasons why both KYB OEM and OEA products have the highest quality standards in the industry.