Kingpin Refurbishment by Kingpin Specialists

How Does Kingpin Refurbishment Work?

At Kingpin Specialists, we provide kingpin refurbishment, repair, and maintenance programs to commercial fleets with trailers. We use an engineered solution and certified welders. But what is the step-by-step process look like and how does it help commercial fleets lower their total cost of operation?

Connection management involves maintaining and repairing both the truck’s fifth wheel and the trailer’s kingpin and bolster plate assembly. When a commercial fleet requires a kingpin to be repaired they will often call us, but before we arrive on-site to do the kingpin refurbishment, a very important first step must be completed to ensure that there isn’t a fleetwide problem.

Performing a Fleet Evaluation

The first thing we perform before doing any kingpin refurbishment is a fleet evaluation. There is no additional charge for this evaluation but it is a very important first step because where there is one kingpin that needs to be refurbished, there are often many more. In fact, many fleets require between 35% and 70% of their trailer’s kingpins refurbished.

During a fleet evaluation, we measure all the trailers’ kingpins to get an evaluation of the wear. We also look at the bolster plates to make sure the frame is structurally sound on the equipment.

In a typical fleet evaluation, our evaluators take 30-45 minutes to go through a fleet and measure up all the trailers. It usually takes two or three trips to capture the majority of the fleet. Once we have that data, we can then compile it. If we can’t get a measurement on a trailer, we can pair it with a similar trailer to get a good picture of where the fleet stands.

Kingpin Specialists is Performing a Fleet Evaluation
Performing a Fleet Evaluation

This will also help predict what needs to be repaired in the future, as well as what needs to be assessed right away and repaired immediately. Once the fleet evaluation has been performed and the fleet commits to the customized maintenance and repair schedule provided by Kingpin Specialists, our technicians go to work.

Staging the Trailers

Trailers are staged in an area for repair onsite, out of the way of daily operations so that it does not impact the rest of the fleet. In most situations, the only thing we need is a flat spot outdoors in natural light, out of the way of traffic. All of our equipment is self-contained, including our power generators.

When we’re working on multiple trailers in a fleet environment, we stage them next to each other so we can be more efficient. When possible, we assign multiple technicians to the job. This way they can weld the first pin and move over to the second pin, while a second tech can machine the pins right after.

This gets trailers back to the customer in the shortest amount of time. When the trailers are staged, we line up the trailers side-by-side and have them raised to a certain height. That way we can get our equipment under the trailer to do the work.

Inspecting the Kingpins

Before we start working on the trailers, we do an inspection process. The upper coupler grid assembly is inspected to ensure that there is no apparent damage.

Kingpin Specialists is Inspecting a Kingpin
Inspecting a Kingpin

The pin is checked for squareness and proper height, and the bolster plate thickness is measured ultrasonically. It’s very important to make sure that the structural integrity of the bolster plate is intact before we perform this process.

Cleaning the Kingpin and Bolster Plate

Removing dirt and grease in preparation for the refurbishment process is an important step that ensures a quality repair is performed. After we’ve completed the inspection process, we clean the kingpin. We use a rag to clean off the grease, then we use heat to warm up the leftover grease, making it easier to finish cleaning.

Starting with a clean kingpin is important because we don’t want to have dirt and grease getting into the metal that we’re applying – it needs to be a nice fluid weld without any impurities.

Pre-Heating Before Welding

After the kingpin is clean, we then apply heat to the pin before we start welding. Pre-heating tempers the pin by bringing it up to the correct temperature to accept the metal. This is very important to create a fluid transfer from the metal we apply, onto the metal of the kingpin.

It’s similar to electrical wiring. When you apply a solder joint, you first heat the conductive material, so you’re not getting a cold solder joint. That would result in metal that’s not fused properly with the copper. The same core principle applies to our kingpin refurbishment process when we bring that pin to a specific temperature. Once it meets our temperature standard, we begin applying the weld.

Welding the Kingpin

In our welding process, we use a spiral weld wrap-up. That means the weld wraps around the kingpin completely. As we fill in the wear pattern, it creates a uniform heat transfer on the pin. It gives us a solid base metal to machine back down to spec.

Machining the Kingpin

Once the kingpin is done with the welding process, we give it time to cool. Cooling allows the underlying kingpin and the weld to bond and solidify. Next, we set up our portable lathe. We’ve developed and patented this portable lathe, which has a cutting bit that squares up the assembly.

A Machined Kingpin Restored to OEM Specs
A Machined Kingpin Restored to OEM Specs

We cut the pin back down to the manufacturer’s spec. In basic terms, we first pour metal on to replace what’s worn away, then we use our portable lathe to cut it back down to spec. We overbuild it, then bring it back down to the operational standards.

Finishing the Kingpin Refurbishment

After the pin has been machined, we inspect it to ensure our weld was intact, our machining is up to our standards, and other quality checks to ensure that our process meets our standard for the pin to be completed. We check for porosity, which is trapped air bubbles in the metal of the weld. We also look for uniformity and that the finish and the specs meet our standard.

We stamp the pin with an identification number, which tracks the welder who welded it, the rod that we used on it, and every aspect of what’s touched that trailer. We’ve never had any problems with our welds, but if there was ever an issue, we want to know what trailers have that material.

Time to Call the Kingpin Specialists

Kingpin Specialists provides an engineered kingpin repair solution performed by certified welders who have been specifically trained with Kingpin Specialists’ industry-leading process.

Without understanding the scope of the connection management issues affecting a fleet, it is impossible to quantify the real long-term costs. It is also difficult to make any meaningful progress in fixing the ongoing connection management issues.

Most in-house technicians do not have an engineered solution at their disposal, lack the experience and training required to repair kingpins effectively, and even misunderstand the relationship between the fifth wheel and kingpin.

If you are responsible for fleet maintenance on commercial vehicles, why not take the first step and have Kingpin Specialists perform a fleet evaluation and report on the condition of your fleet?

Call us at 1-888-221-7774 or email us at

When Kingpin Specialists is done with your trailers, you will be done with excessive wear and damage to your kingpins and fifth wheels.

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