Trailers are a matter of economy and efficiency. They add value and possibilities to any tow vehicle, but they also add liabilities and responsibilities. Towing isn’t quite as simple as hitching a trailer to your truck and heading down the road, but anyone who is comfortable behind the wheel of a vehicle can master the art of towing.
The Right Rig
For hauling livestock, you can use a general-purpose stock trailer. Ranchers often prefer a pipe-and-panel stock trailer with at least one fore-and-aft partition. Those trailers can easily accommodate a small tractor with implements, as well as move a teenager off to college (you might want to clean it first, depending on the teen).
Specialized hog and sheep haulers have a lower height.
Open-deck flatbed trailers are perfect for moving machinery, and can be loaded with bulk freight from virtually any angle. These handy haulers come with plenty of load-securing attachment points for chains and binder straps, and are also equipped with evenly spaced stake pockets, which can hold removable side panels and livestock compartments.
Hydraulic dump trailers are useful for hauling bulk materials, such as feed, grain, manure, gravel, mulch and sand. Many dump trailers can also accommodate a small tractor or utility vehicle (but probably not the college-bound teen).
Utility trailers are generally light-duty. Smaller models are suitable for hauling lawn and garden tractors or other light materials, such as bagged mulch.
Calculate Trailer Capacity
The inexperienced hauler often assumes that size is what matters when choosing a trailer, but weight is more important. Consider a 16-foot tag-along livestock trailer with a 5,000-pound gross vehicle weight rating (GVWR). While it might have room inside for four 1,500-pound bulls, simple math reveals that you can’t haul 6,000 pounds of bull at once. So, how much bull can you haul?
The stock trailer’s 5,000-pound GVWR includes the combined weight of the trailer and the cargo. The trailer weighs 2,500 pounds when clean and empty, so its payload capacity is 2,500 pounds. Or is it? The trailer’s GVWR is based on the capacity of its axles and, to some extent, its framework, but what about tires? Our test-case trailer has a pair of axles underneath, each with a 2,500-pound gross axle weight rating (GAWR). But the four tire sidewalls show that they’re rated for 1,000 pounds each.
This brings the actual GVWR down to 4,000 pounds, which leaves enough trailer capacity to haul one of the 1,500-pound bulls after deducting the 2,500-pound weight of the trailer. If the trailer is full of manure or caked with mud or ice, it won’t have enough capacity to haul even one bull. In summary, to calculate actual capacity, choose the lowest weight rating from the GVWR, GAWR and tire ratings, and then subtract the actual weight of the trailer.
Just as critical is knowing whether your tow vehicle is suited to a specific trailer. Vehicle manufacturers provide a gross combination weight rating (GCWR), which is defined as the combined weight of the loaded trailer and truck when hitched together. The GCWR sets the highest weight limit for total payload.
Hitching a Trailer
If you tow with a pickup, frame-attached hitch mounts are typically located ahead of the rear axle (“gooseneck” or “fifth-wheel”) or behind it (“tag-along”). In many cases, the pickup’s rear bumper is rated as a hitch mount, and many farm trailers are coupled to balls bolted to the bumper’s center. Most vans and larger SUVs can be outfitted with hitch mounts attached to the frame behind the rear axle; some come equipped with rear bumpers with towing capacity.
The hitch receiver is an ideal mount: a 2-inch-square steel socket centered beneath the rear bumper. The socket is designed to receive different hitches, which can be pinned into the socket and easily swapped for a different style.
The most commonly encountered hitch systems match a ball on the tow vehicle to a socket coupler on the trailer’s tongue. All have a specific weight rating. Light-duty tag-along hitches are generally rated for trailer tongue weights of less than 500 pounds. Weight distribution attachments, required for towing tag-along Class IV and heavier unclassified trailers, apply leverage across the hitch and place some of the trailer’s load on the tow vehicle’s front axle to keep tongue weights within specification. Other heavy-duty tag-along trailers might be equipped with a ring-shaped coupler “lunette eye” — a pintle hook on the tow vehicle is required to make that hitch.
When routinely towing heavier or longer loads, gooseneck or fifth-wheel systems are ideal. These heavy-duty hitches are sometimes rated for up to 25,000 pounds GVWR. The gooseneck system consists of a 2-5/16-inch-diameter ball located in the truck’s bed, attached to its frame through a heavy-duty mount, and a large socket coupler built into the trailer. The fifth-wheel system consists of a slotted plate “fifth-wheel” with a retaining latch located in the pickup’s bed (solidly attached to the truck’s frame) and a kingpin coupler on the trailer. Nearly every semitrailer combination on the highway today has this hitching system. After hitching a trailer to a tow vehicle, both need to share an electrical system so that all required lights on both vehicles operate together. This coupling is accomplished with standard plug-and-socket combinations; use an adapter if the plug and socket don’t match.
Higher GVWR trailers are often equipped with electric brakes or electrically actuated hydraulic brakes. Power for these braking systems comes from the tow vehicle’s electrical socket via an inertia-sensing brake controller that keeps them in sync with the tow vehicle’s brakes. Hit the brake pedal hard, and the trailer will brake rapidly and with more force than it would with a lighter touch. Most controllers allow manual trailer-brake
activation and power adjustment to accommodate different loads.
Load Control and Towing Safety
Each trailer’s GVWR is based on an evenly distributed, maximum payload, which is easy to achieve with grain in a dump trailer, but not so easy with sheep in a livestock trailer. As you fill any trailer, do your best to distribute the weight as evenly as possible for adequate load control and safety. Static loads are more predictable and safe, so confine livestock or liquids, if at all possible. Their movement should be limited to have minimal effect on the trailer’s tongue weight or pitch. You can successfully load dry goods into an enclosed trailer with careful packing, but strap portions of the load to the trailer’s floor or walls to avoid shifting.
Securing freight on a flatbed is an absolute must — even if it’s just a load of hay. State and federal Department of Transportation (DOT) load-binding rules continually evolve — check your state DOT’s regulations at least once a year. Exceeding the binding system’s weight rating is a sure way to earn an expensive ticket or huge liability damages if it fails — even in an accident that isn’t your fault.
Trailer tongue weight should be approximately 10 percent of a trailer’s loaded weight. This is critical for tag-along trailers because goosenecks and fifth-wheels are designed with an unladen tongue weight approaching 10 percent of the GVWR. Moving freight forward increases the tongue weight, which can overload the truck’s rear axle and lighten its front end enough to make steering difficult. Moving freight behind the rear trailer axle can result in negative tongue weight and cause tow vehicle instability.
This article was adapted from our sister publication, GRIT Magazine.
Trust Your Mirrors
Backing up requires low speed, vigilance with your mirrors, and knowledge that the trailer will move in the opposite direction that you steer the tow vehicle. For example:
A driver needed to maneuver a small trailer around a gradual 90-degree curve. She pulled the entire rig straight forward ahead of the turn (A) and began to back up. Note that she started by turning the car’s front wheels to the left (B). In reverse, that made the back of the car head left, which pulled the trailer’s coupler to the left, effectively aiming the rear of the trailer to the right.
Well into the turn, the driver turned the car’s wheels slightly to the right (C) to allow the car to follow the trailer and to end the turn. (Novices tend to overcorrect at this point — rather than gradually straightening the truck with respect to the trailer, they cause the trailer to turn opposite the desired direction. If that occurs, get out of reverse and pull the rig forward to straighten things out before backing up again.)
For this maneuver, the driver watched the right-side mirror, or the same side as the turn. Resist the urge to look over your shoulder — hitting a fence post with the front of your vehicle as it swings around a curve is just as frustrating as backing into a tree.
GRIT Magazine’s Editor-in-Chief Hank Will has pulled many types of trailers over thousands of miles, carrying hay, livestock, machinery, and even his children’s household goods. He installs his own hitches, secures his own loads, and takes towing safety seriously.