Choosing the appropriate coupling equipment makes heavy hauling safer and easier

When you are hauling the heaviest loads on the road, finding the right coupling equipment can be challenging.

Heavy haulers know the story all too well – when hauling heavy loads, a big challenge is finding the right coupling equipment.


A big issue is weight capacity. Many manufacturers that produce pintle hitches do not list the capacities; for anyone in the heavy haul industry, that is a non-starter. Given the inherent  dangers of trailer separations, you must know the weight capacity for any pintle hitch. The U.S. saw nearly 1,000 accidents involving trailer separations from 2009-2018, and whenever trailer separations occur, they usually involve a fatality (1,156 people were killed in trailer separation accidents from 2009-2018).

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As a result, some coupling manufacturing companies have invested a lot of time and resources into developing new technologies. In fact, one new hitch on the market closes with the release of the emergency brakes. 

Making sure the latch is closed correctly is always the responsibility of the person making the coupling connection, and it is the driver’s responsibility to verify that the equipment is correctly connected before moving the vehicle. Mistakes happen, and a great plan B is invaluable. Any coupling that can help prevent catastrophic accidents saves countless lives. Fleets are taking note and starting to notice these life-saving trends. 

Another feature that affords greater comfort and safety is adding a type 30 air service chamber for use with a slack-reducing coupling to any heavy haul application. This type of air chamber applies up to 3,000 PSI to dampen heavy loads via the pushrod, so a type 30 air chamber is the safest and most reliable for anyone utilizing this style of coupling.  By reducing the slack in the connection, the load is hauled much smoother and safer while the coupling equipment benefits with a much longer useful life. 

Grade 8 fasteners are necessary with all pintle hitch applications, but any heavy hauler should look at grade L9 fasteners to ensure the coupling does its job. With a tensile strength of 180,000 pounds per square inch, L9 fasteners are perfect for high-stress environments and supply the additional strength needed to confidently carry any load down the road. Fleets should always check with the coupling manufacturer to ensure they use the highest quality fasteners.


Of course, when discussing coupling equipment, the pintle hitch only tells half the story. You must also ensure the drawbar eye’s weight capacity is acceptable for your load and application. A chain is only as strong as the weakest link; thus, the drawbar eye needs to be equally rated for the capacities specified by the fleet. 

Speaking of applications, some heavy haulers see rough terrain as part of their run, so it is essential to use an appropriate front-end assembly that can handle the uneven path. Some suppliers produce a front-end assembly containing a swivel drawbar eye, and that tandem can easily handle the roughest of roads. However, in that case, companies must ensure that the swivel drawbar eye carries an appropriate weight capacity.

If a company experiences rough terrain and is not using a swivel drawbar eye and front-end assembly, the coupling can wear more quickly. Therefore, consider the coupling material before making a final decision. Not all pintle hitch and drawbar eye materials are created equally, so examine the compounds used during manufacturing. Some materials on the market work-harden, meaning that as friction builds up on the coupling surface, the material gets harder and harder. In this way, it is similar to material found in railroad rails.

A set of heavy-duty hinge assemblies will also dampen the load of your drawbar assembly. Pair these with a set of poly bushings, and they will absorb the extreme weight of heavy hauling. Some manufacturers offer hinge assemblies rated at 150,000 lbs. Nylatron bushings are also a great option for many heavy haulers. Nylatron is a NASA-approved material with unique characteristics that will outperform most polymer materials in a heavy haul application.


Considering the weight involved with heavy hauling, it is essential to monitor the wear of all coupling equipment, and some manufacturers offer accessories to monitor and assess the wear of their products. 

Using tools such as wear gages will help identify critical wear on the horn and drawbar eye and help a company plan for any potential replacement equipment. Nobody wants to be caught behind the eight ball without a replacement option on hand, and many wear gages will indicate when a new product should be ordered. 

Some wear gages come with a latch gap measuring device, which – if it passes through the gap between the horn and latch when the latch is closed – recognizes when a coupling should be taken out of service. Wear gages and latch gap measuring devices can play an important role in properly maintaining coupling equipment.

Some suppliers also provide step-by-step guides for choosing the appropriate coupling equipment. This is a huge help for any company in the heavy haul industry. Sometimes, manufacturers even provide an online web site tool that walks users through identifying the correct part number.

Weight plays the biggest role when selecting the right coupling equipment for heavy hauling, but there are numerous ways to increase safety and make things easier for drivers. When questions arise, it is best to contact the coupling manufacturer directly for advice on the best coupling equipment for specific hauling requirements.


Caleb Ostrander is a marketing specialist for High Bar Brands, which acquired Premier Manufacturing in 2020. Premier Manufacturing has been designing and manufacturing coupling equipment for nearly a century.  To learn more, visit

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