How Much Weight Can Semi-Trailer Landing Gear Hold?

How Much Weight Can Semi-Trailer Landing Gear Hold?

We know that there are many landing gear products on the market to choose from, and it can be overwhelming to find the one that fits the specs of your trailer. One important deciding factor is how much weight your semi-trailer landing gear can hold. We’re here to break it down for you.


What Is the Purpose of Semi-Trailer Landing Gear?


Trailer landing gear is the retractable support equipment that keeps a trailer level when removed from the semi-tractor. It’s located at the front of the trailer and will keep you and your truck safe. The landing gear consists of two legs that can support the heavy weight of the trailer. 


Jost Landing Gear

What Are the Different Types of Semi-Trailer Landing Gear?


Here at JOST International, we’re an industry-leading manufacturer of trailer landing gear and component parts. We offer an expansive product line, and our signature internal gearbox is the key feature and integral part of our landing gears’ durability and . Our internal gearboxes protect the gears from damage and significantly reduce moisture intrusion, which extends the product’s life and provides our customers with a stronger, more reliable product.

While there are several types of semi-trailers landing gear, most can be divided into either drop legs or standard landing gear legs. Here’s what you need to know about both. 


Drop Legs


Drop leg landing gear products utilize a spring-loaded lower tube. The drop handle must be turned 90 degrees to disengage. The internal spring keeps the drop leg retracted until the force is applied. A smaller spring on the drop handle forces it inward, allowing the drop handle to align with the following hole location as the internal spring retracts the lower tube.

Drop legs are ideal for various commercial trucking applications looking to save operator time and overhead costs. They’re lightweight, easy to use, and perfect for smaller loads and drivers looking for an efficient way to speed up the coupling and uncoupling process. 

landing gear drop legs

Landing Gear Legs


Our landing gear maintains all the mechanical advantages of JOST’s drop legs, but trades the spring drop function for a more durable,single speed and two speed crank mechanic only. JOST internal gearboxes are completely filled with premium all-weather lubricant, an elevating screw that can be fully encased in a grease tube, completely sealed landing gear legs, and austempered ductile iron gears.

JOST landing gear is ideal for heavy-duty applications. They’re the best option for protecting against water and chemicals on roads. 

For a complete guide to the full JOST International product line, download our Trailer Products Catalog


How Much Weight Can Semi-Trailer Landing Gear Hold?


At JOST International, each of our high-quality landing gears has its own standout features, including weight capacity. If you need to find the perfect semi-trailer landing gear for you, ask yourself these questions:

  • What’s your application?
  • How much weight do you need to support?

A JOST landing gear product can support:

  • Static Load Capacity: 160,000-200,000 lbs
  • Lifting Capacity: 55,000-70,000 lbs

Note: Varying models are available to support both heavier and lighter applications. 

A JOST drop leg product can support:

  • Static Load Capacity: 12,000–35,000 lbs
  • Lifting Capacity: 12,000-35,000 lbs

Note: Varying models are available to support both heavier and lighter applications. 

If you’re interested in JOST International landing gear, take a look at our Landing Gear Spec Sheet and Drop Leg Catalog to see each of our product options and the weight associated with each. 


Invest in High-Quality Semi-Trailer Landing Gear


If you’re looking for superior landing gear from an industry-leading manufacturer, JOST International is here for you. Our landing gear meets or exceeds international standards for OEMs and fleet use in North America and internationally. Plus, we use top-of-the-line technology, so you can always trust that you and your equipment will stay safe. 

Visit our website or contact our team today to learn more!

What is a Kingpin on a Semi?

What is a Kingpin on a Semi?

Whether you’re new to coupling trailers or you’re just trying to get a handle on all of the technical part names, the JOST team is here to provide all the information you need around fifth wheels and industrial transportation.

In this article, we’re discussing the basics of kingpins for semi trucks. Here’s everything you need to know about what a kingpin is and what it does.

What is a Kingpin?


Frequently referred to as the “pivot point between the tractor and semi-trailer,” the kingpin is the part used to connect a semi-tractor and a semi-trailer. A kingpin may resemble any of the above images but always shares a few key features:

  • A welded side. One side of the kingpin is always welded to the semi-trailer. This is why kingpins are often considered a “trailer solution” rather than a “truck solution.” They are always fixed to the trailer and then coupled with the tractor using a fifth wheel coupling device.
  • A tapered section. Every kingpin has a tapered section that is narrower in width than the sections above and below it. This is where the fifth wheel locks around the kingpin to provide a secure coupling. By making the areas above and below the tapered area wider, manufacturers ensure another layer of protection, minimizing the potential that a kingpin could slip out of a fifth wheel’s coupling mechanism.

What Does a Kingpin Do?

This small but mighty part comes in a variety of shapes and sizes, but works to do one thing: connect the semi-truck and trailer.

In addition to that primary function, a kingpin is also responsible (in partnership with the larger fifth wheel) for the steering and handling of the coupled rig. When properly coupled, the kingpin keeps the trailer and tractor together while allowing the tractor to turn and pivot around its fixed point, ensuring semi trucks are able to transport product with ease.

What Should I Look For in a Good Kingpin?

If you’re in the market for a new kingpin, you might be wondering how you decide from all the different kingpin types and manufacturers. Here are 3 key things to look for when purchasing a kingpin you can trust to keep you safe for years to come.

01. Durability

A kingpin is only as good as its lifespan. This is an integral component for any rig, and should the kingpin fail, your trailer cannot move. That’s why it’s important to look for a kingpin with proven durability. To assess this, evaluate:

  • Manufacturing materials. What is the kingpin made out of? A kingpin made from high-quality steel is likely to last significantly longer than a kingpin manufactured with poor-quality materials.
  • Manufacturing methods. We’ll talk more about manufacturing requirements and standards below, but how a product is manufactured can tell you a lot about how it will perform. Choose kingpins from manufacturers with safe, reliable manufacturing standards and safety requirements.
  • Manufacturer standards and warranties. Does the manufacturer stand behind its product with a warranty or stringent manufacturing standards? If not, you may have a problem finding a kingpin that can stand up to long hours of wear and tear on the road.

02. Safety

Perhaps the most important feature of any kingpin is its ability to keep the operator and the rig safe. Choose kingpins from reputable manufacturers with a long track record of safe manufacturing practices. Quality manufacturers will be happy to provide you with the information you need to verify the safety of their products.

03. Local Standard Compliance

Every trailer OEM has its own international standards. Your trailer must meet those standards to ensure safe, compliant hauling in your area. To ensure you’re in compliance, first find a manufacturer that produces kingpins according to your local standards, and then verify their compliance. A great manufacturer will prove with data how their kingpins meet established performance requirements.

If you’re not sure what standards to look to, the most popular standard compliance requirements in North America include:

  • SAE (Society of Automotive Engineers) specification for dimensions, materials, and installation).
  • AAR (Association of American Railroads) specification for SAE dimensions and greater installation, structure, and material strength/wear specifications.
  • TMC (American Trucking Association — Technology and Maintenance Council) RMP-750 – kingpin and upper coupler inspection for deformation and wear replacement standards.

Safe hauling starts with safe parts. And no one manufactures for safety better than JOST international. If you’re looking for a superior kingpin from an industry-leading manufacturer, JOST can help. Our kingpins meet or exceed international standards for OEMs and fleet use in North America and internationally.

5 Symptoms of a Bad Kingpin

5 Symptoms of a Bad Kingpin

The kingpin of a trailer is a small but essential component. It’s responsible for coupling a trailer to a tractor, which means its one of the few things keeping a rig together on the road. Operators know that the kingpin is the last thing you want to go bad while you’re on the road, but how can you identify a bad kingpin before it becomes a problem? Here are 5 symptoms of a worn or bad kingpin to look out for every time you’re coupling or uncoupling a trailer:


1. Hard to Couple

If you’re having problems coupling a trailer on the tractor, it could be a sign that you have a bent kingpin or upper coupler.

A kingpin that is in great shape should make it easy to couple your tractor and trailer. So, if you’re noticing problems with a specific trailer, the kingpin could be to blame.

What’s the cause? In the case that you’re having trouble coupling your trailer, the issue could be a result of a worn or failing upper coupler structure.

Why fix it? If your kingpin or upper coupler are bent, not only are they making coupling more difficult, but they’re no longer supporting your trailer and cargo safely. This is an unsafe way to haul, and it’s also a leading cause of accelerated top plate surface wear.

In any case, the best solution is to have the upper coupler structure and kingpin inspected and replaced if possible. You’ll spend less in the long run by addressing the problem now rather than waiting for it to affect other parts of your rig.

2. Hard to Uncouple

Maybe your tractor and trailer coupled just fine, but now you’re having problems uncoupling them. This is a key sign of a bad kingpin. The symptoms here are similar to those that occur when it’s difficult to couple a trailer, and it’s also usually a sign of a bent kingpin or coupler.

This is another fix to make as soon as possible. If you’re unable to have the problem addressed, a bad kingpin can add significant wear to your tractor and fifth wheel. What’s more, it’s an unsafe way to haul. It’s always best to get a bent kingpin fixed as soon as possible.

3. Fifth Wheel Adjustment Will Not Tighten — Worn Down Shoulder

If you’re experiencing problems with your fifth wheel adjustment, it’s usually a sign of a bad kingpin. There are two issues that could be causing this, the first of which is a worn-down shoulder.

When the shoulder of the kingpin wears down, it becomes impossible for your fifth wheel adjustment to tighten securely. There’s not enough material for the fifth wheel to tighten against, and if you cannot tighten your fifth wheel adjustment, you cannot safely haul.

This is a sure sign of a worn kingpin in need of replacement. The best solution is to address this as soon as possible by installing a new kingpin.

4. Fifth Wheel Adjustment Will Not Tighten — Worn Down Throat

As mentioned, there are two key problems that will prevent a fifth wheel adjustment from tightening. The first was the worn-down shoulder, and the second is a worn-down kingpin throat. When this happens, the throat has become so worn down that there is nothing for the fifth wheel adjustment to tighten against.

This presents a similar problem to a worn-down kingpin shoulder, which is that the coupling cannot be safely secured. Here too, it’s essential that you replace the kingpin before using the trailer. It is unsafe to haul if the coupling cannot be secured properly.

5. Lack of Lubrication

The fifth and final symptom of a bad kingpin is a lack of lubrication. If a kingpin has been poorly lubricated, excessive wear can happen quickly — and excessive wear is a surefire sign of a bad kingpin.

The kingpin and fifth wheel should always be well lubricated to reduce grinding between the tractor and the tractor’s fifth wheel. If the kingpin is not properly lubricated, it will wear unevenly and prematurely, which can create unsafe hauling conditions.

Signs of poor kingpin lubrication include the galling of kingpin contact surfaces and premature wear. If you know that a kingpin is not at the end of its life but is showing significant wear, a lack of lubrication is likely the problem. Unfortunately, once worn down, and especially when worn down unevenly, and kingpin must be replaced to ensure the safety of the operator and the rig.

Invest in a Better Kingpin

Forget the symptoms of a bad kingpin when you invest in a better kingpin developed by experts in the commercial transportation industry. JOST kingpins have proven themselves mile after mile over the world’s most challenging roads. They’re built for quality, safety, and durability. If you’re ready to upgrade, we have the solutions you need. Find a dealer near you.