How to Reduce Kingpin Wear

How to Reduce Kingpin Wear in a Heavy-Duty Fleet

Our technicians crawl under thousands of trailers every year to evaluate wear patterns and assist fleets to reduce kingpin wear and bring their equipment back into compliance. There are many variables that could cause excessive wear in a fleet, including the type of trailers and use patterns.

So how can you identify the root cause of your fleet’s excessive wear and reduce kingpin wear?

We recommend a three-step process to identify the cause of a fleet’s excessive wear and get all equipment back into compliance. Each fleet is unique, but let’s look at the general risk factors that make connection components wear too quickly and what needs to be done to reduce kingpin wear.

What kind of fleets is at risk for excessive kingpin wear?

The type of work your fleet performs is a major factor in your wear rate. Long haul trailers with limited stops and disconnections typically will have low wear as the connection components experience limited stress.

As the connection components experience more stress the wear rate increases. Liftgates, auto unload floors, liquid transportation, and daily routes with multiple stops all create aggressive wear environments.

If your fleet is experiencing much higher wear rates than it should, there may be some other factors speeding up wear. If any of your connection components are heavily worn, the wear will spread like wildfire through the fleet, causing even more damage.

Also, older components wear faster, so if much of your equipment is older, you could be seeing more accelerated wear. Finally, seemingly insignificant factors like bumpy roads, unbalanced loads, and unlubricated components can contribute to excessive wear.

How do I reduce kingpin wear and keep it under control?

There is more to a kingpin than most people realize. To identify a wear problem and get the root cause, you have to isolate the variables so you can identify where the problem is coming from. This is the only way to reduce kingpin wear long-term.

When a fleet asks us “Why are we seeing so much wear?” there may be several factors that have created the wear pattern the fleet is experiencing. 10-20 years of neglect requires several years of correction and routine maintenance to provide a proven solution.

A Welder is Repairing a Kingpin for a Fleet that wants to Reduce Kingpin Wear
Kingpin Specialists Repairing a Kingpin

Below is an overview of a three-step approach we recently used with a fleet to identify anomalies and reduce kingpin wear.

Step 1: Reduce the Variance

The first step is to reduce the variance among the equipment in your fleet. Let’s look at one of our past clients as an example. Fleet A started out with an average wear rate of .025”. Out of their 220 trailers, there were 135 trailers that were close to or exceed the manufacturer’s operational threshold. That’s around 60% of the fleet being close to or exceeding the out-of-compliance threshold!

The high wear rate was not unexpected in this case. The variance between new equipment coming in and the high wear levels on the older equipment was overly stressing the connection components, causing excessive wear.  To reduce the wear rate, we had to bring the variance between new and used equipment under control.

Trailers that were going to be kept in service were repaired within a matter of weeks. Meanwhile, the in-house maintenance technicians focused on repairs and adjustments to the fifth wheels. When we re-evaluated the wear the next year, we saw an immediate reduction to the wear rate, which had dropped to an average of .015” a year.

Step 2: Preventative Maintenance

With the fleet seeing a better wear rate, we began a preventative maintenance program repairing the kingpins at a recommended wear level.

By repairing the equipment proactively, we can further reduce the variance across the fleet which helps reduce the stress on the connection components.

Taking a two-year budget-conscious approach, we brought the fleet to a maintenance level repair standard. During that time, we continued evaluating the wear rates and looked for anomalies.

Step 3: Yearly Evaluations and Monitoring

The overall fleet wear had reduced to .012” a year. However, we noticed this average was being driven up by the 28’ trailers. Some of the 28’ trailers were still seeing a .015 -.020” wear rate.

After digging into the data, we could see that the trailers with the high wear were being used as doubles. When one tractor is pulling two trailers (doubles), the first is attached to the tractor and the second is attached to a dolly. The in-house technicians confirmed to us that the fleet’s dollies needed service as well.

The following year, the fleet’s overall wear rate averaged .009” a year. The fleet has continued the preventative maintenance program and has seen a stable wear rate averaging around .010 a year for the past 5 years. That’s a 60% reduction in wear rate!

Time to Call the Kingpin Specialists

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 which will reduce kingpin wear.

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 an inspection and report on the condition of your fleet?

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

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