Kingpin Repairs for Commercial Trailers

step 1 INSPECTION

Before a Kingpin can be refurbished it must pass a general inspection. The Upper Coupler/Grid assembly inspection is performed to ensure that there is no apparent structural damage. The pin is checked for squareness and proper height. The bolster plate thickness is measured ultrasonically and visually inspected for cracks and deformations. If the upper coupler does not meet the inspection criteria, then refurbishment is not recommended. When evaluating fleets our technicians will inspect multiple trailers on a single visit. The wear levels and structural assessment is noted on an inspection report that is provided to the fleet service manager.

step 2 CLEANING

Once the kingpin has been inspected and approved for repair, the trailer will get staged out of the way of daily operations on a level area. The technician will clean the pin removing any dirt and grease in preparation for the refurbishment process. This minimizes any foreign compounds from integrating with the weld and allows the technician to evaluate the wear pattern and customize the weld overlay to build up the needed material to compensate for the wear. As the technician cleans the pin a second assessment of the upper coupler is completed to ensure no cracks or anomalies are present on the bolster plate.

step 3 PRE-HEAT

After cleaning the kingpin our certified technician’s setup, a specialized seat to begin the repair. Before the technician can apply the spiral weld wrap a preheat process is needed. Heat is applied evenly to the Kingpin to bring it up to the target temperature. Preheat and interpass heat must be maintained to ensure consistent hardness in the remanufactured kingpin. If there is too much variance in temperature, hardness becomes inconsistent, and will be difficult to machine. Wearable components need to be comprised of consistent material so that they wear evenly.

step 4 WELD

Our technicians follow an engineered process applying spiral weld wrap to the pin. Once they begin the process the technician must continue the work until it is completed. Just as with the preheat process you want to keep the temperature within your target zone to maximize the consistency within the metal applied. Throughout the process the technician uses a spiral overlay incorporated with tempered welds to ensure strength and consistency of the weld over the kingpin. This non-invasive process does not alter the structural composition of the upper coupler assembly. The weld is only applied to the wearable sections of the Kingpin.

step 5 MACHINE

After the kingpin has been built back up our technician’s setup our patented “POVOL” (Portable Orbital, Vertical Operating Lathe 2.0). This custom tool allows us to machine the kingpin onsite while still attached to the trailer. As the extra material is removed the consistent solid core is revealed. The result is a remanufactured kingpin that has the similar metallurgical properties and dimensions that coincide with the manufacturer’s operational specifications. All Kingpins are dimensioned to the J700 and J2228 hardness and dimensional specifications.  The extra material that was removed is cleaned up with a magnet and the kingpin is double checked to ensure it meets the quality checks. 

step 6 FINISH

After the kingpin machining is completed, the pin must then pass a post-production test ensuring that it complies to our internal quality control standards. If the pin does not meet our established standards, then the complete refurbishment process starts again. Once the kingpin has passed the quality control checks the pin is stamped with a unique ID# and a certified refurbishment sticker is applied to the trailer. This unique tracking number tracks all aspects of the refurbishment for start to finish. Our Kingpin rebuilds are 100% guaranteed to operate and function just as a new pin would.