If your idea of a good time is climbing onto the back of rodeo stock bred and raised to throw a rider, you can expect a good deal of bucking, but when it comes to towing a fifth-wheel trailer, it’s the last thing you expect or want in your ride.
The hardware that connects your truck and trailer can make a big difference in how they behave on the road. There are two sides in the truck-to-trailer connection that are critical to the fifth-wheel towing setup. In a recent article (“5th And Go Forth,” September 2012 Trailer Life) we explored the available options for fifth-wheel hitches, which can accommodate short-bed pickups or can improve ride quality and ease of use for your trailer and tow vehicle combination.
Now it’s time to explore the trailer half of the fifth-wheel connection equation, the pin box. The primary function on the pin box is to fix the kingpin at a certain location and angle in relationship to the front of the fifth-wheel trailer. Its most important characteristic is structural integrity, creating a strong connection from the trailer frame to the kingpin. The term “pin box” is the industry standard and describes the most common design, which is a box frame because it is a good way to make flat steel strong enough to handle the loads much like the truck manufacturers are now building frame rails.
The box design also allows for some interesting options in terms of reach, pin placement, cushions, tilt plates, shock absorbers and air bags. This is where aftermarket pin boxes come into play. They can improve ride quality, increase control, create a tighter turning radius and create more room in your pickup bed.
Premium pin boxes can also be used in conjunction with different styles of hitches to address issues not solved by the hitch. For example, your slider hitch allows your short-bed pickup to tow a fifth-wheel, but you could use some improvement in ride quality. A pin box can help without having to replace the entire hitch. If you already have air bag suspension in your truck but are experiencing the fore and aft jarring known as chucking, you can use a pin box designed to address that very annoyance.
When you’re shopping for pin boxes, knowing the make, model and serial number of your trailer is important. Make sure a change of pin boxes doesn’t affect the warranty coverage of your trailer and its frame. For example, Lippert Components, which builds RV chassis, has endorsed specific Reese pin boxes as replacements.
If you have a shortbed pickup then clearance to the cab of your pickup is at a premium. Fortunately, there are pin box solutions designed to help you achieve the clearance you require. An extended design helps the pin box reach out further from the frame of the trailer or by some other creative means. PopUp offers a bolt-on pin box extension gaining you 10 inches of reach with the kingpin and is suitable for use on many fifth-wheels and with most hitches.
Reese’s Sidewinder approaches the issue from another angle using a capture plate that moves the pivot of the trailer from the hitch point back to the trailer mounting area, giving you more room and freeing up space you’d have to leave clear in the bed with a normal-style hitch and pin box setup.
Many of the ride quality issues associated with fifth-wheel trailers come from the uneven road surfaces that can translate into movement in the trailer. Without a specialty pin box, this movement can transfer into the tow vehicle producing a jerky ride and eventually causing wear to the chassis of the vehicle. The same stresses that affect the tow vehicle are also being exerted on the trailer’s frame and structure. A pin box that helps absorb the seesaw action between truck and trailer can save wear on the rider and vehicles.
Damping in a pin box can be achieved through a variety of technolgies. The best fit will be determined by specific characteristics in your truck and trailer setup, such as how well it handles road conditions.
The unit from MOR/ryde features a rubber shear spring that resists movement not only fore and aft, but also side to side. This style of damping is maintenance-free and is available in different trailer weight ratings.
Using air bags to improve ride quality is an approach used by a few companies but the implementation, the number of bags and the assistance of a shock to damp movement are some of the variations.
Air bags allow you to change the ride quality according to the current load of the trailer by simply changing the air pressure of the system. The use of shock absorbers helps the units stabilize the movement of the trailer and reduce shock and dampens the ride. The TrailAir unit and the Reese 5th Airborne use air bags and shocks to improve ride quality. Air Safe’s pin box solution uses four air bags, which are connected, but it doesn’t employ shocks or other more rigid components.
Demco uses a parallel linkage system to address the fore and aft. The system always returns back to center using gravity and damps the jerking of the trailer from the imperfections in the road without recoil.
If you already have a pickup setup with a gooseneck and don’t want to hassle with installing a fifth-wheel hitch, you can get a conversion hitch setup like those available from PopUp hitch or an entire Goose box replacement like the unit available from Reese. These give you the option of using your existing gooseneck-style hitch in your bed while providing a better ride quality with extra cushioning built in.
Be sure to thoroughly identify your towing concerns. Double check tire inflation, hitch location and trailer cargo distribution to eliminate variables. Make sure you choose a pin box that matches load requirements and that is designed to address the type of bucking your bronco is doing.
The Sidewinder from Reese is specifically designed for short-bed pickups and allows up to 90-degree turns. It automatically maximizes maneuverability without the need to throw a switch or push a button. The Sidewinder allows you to use the full cargo area in your pickup bed, without the need to leave clearance for pin box movement. The pivoting pin box allows you to hook up easier because you can connect at any angle. The unit gives you faster steering response allowing easier back up with greater control. The Sidewinder is available with air-ride and is backed by a limited lifetime warranty.
The Reese 5th Airborne acts as a buffer between the tow vehicle and the trailer to help smooth the ride by reducing stress, jarring and vibration. The pin box utilizes a forward pivot, enclosed air bag and rear-mounted shock absorber. The forward pivot works in harmony with your hitch pivot, while the air bag is protected from UV exposure and road hazards in the enclosed aerodynamic housing. The 5th Airborne is designed to reduce horizontal chucking by 60 percent and vertical shock by up to 44 percent. It offers worry-free operation and is backed by a limited lifetime warranty.
Do you need the features of the Sidewinder and the smooth ride quality of the 5th Airborne? The Reese Elite Airborne/Sidewinder gives you the best of both worlds. The 5th Airborne combined with the Sidewinder gives you the smooth ride and easy turning in one premium pin box. The Elite Airborne/Sidewinder improves the towing experience both on the road and while maneuvering in camp, and is backed by a limited lifetime warranty.
The Goose Box from Reese is a hybrid of sort that allows towing your fifth-wheel trailer with your gooseneck hitch while providing a smooth, stable ride using an air-ride equipped coupler. The fully enclosed air bag and dual shock absorbers cushion and absorb road shock, decreasing vertical shock or bounce, and longitudinal shock or chucking. This limits strain on truck and trailer frames while the pivot tube helps to minimize jarring by allowing fore and aft movement. The unit is endorsed by Lippert Components, so it will not affect the warranty on its trailer frames and is made in the USA, and backed by a limited seven-year warranty.
The MOR/ryde rubber pin boxes (RPB) have available models to match all of the OEM pin boxes on the market. It gives a cushioned sensation over uneven road conditions and offers jerk-free starts and stops. The RPB greatly reduces back and forth chucking and jerking making for a smoother, more comfortable in-cab ride. MOR/ryde’s RPB utilizes a unique rubber shear spring which works in a horizontal planar motion to absorb the towing shock. MOR/ryde’s pin box system is bolt-on and typically takes about one hour to install.
The Glide Ride absorbs bumps and jolts through a gravity self-centering parallel linkage system. Demco’s pin box protects your pickup and fifth-wheel by reducing the stress applied to the drivetrain, suspension, body and tires. The pin box is designed to smooth out the ride while helping to reduce potentially costly repairs and extending the life of your vehicle. The Glide Ride operation is maintenance free and doesn’t affect braking or steering. Available in multiple fits for different manufacturers’ pin boxes with up to a 21,000-pound gwr.
PopUp Towing Products
The RV5 is a 10-inch kingpin extension. It attaches to the trailer’s existing kingpin with a heavy (nearly 20-pound) machined steel clamp and also bolts to the bottom of the kingpin box. The added distance between the cab of the truck and the nose of the trailer is especially needed for many short-bed trucks, allowing for shorter turns. The RV5 is a serious piece of equipment, it’s laser cut from half-inch plate steel with computer precision and powder coated for a long-lasting finish that will look great on your trailer.
The RVCC is the newest in the line of fifth-wheel-to-gooseneck adapters from PopUp Towing Products. It attaches to the trailer’s kingpin with a heavy (nearly 20-pound) machined steel clamp and also bolts to the bottom of the kingpin box. It allows a fifth-wheel trailer to be pulled with a gooseneck ball in a pickup. It’s adjustable in height, from 13.5 to 17.5 inches, to fit a variety of truck/trailer combinations. It also features a 7 1/2-inch extension with the coupler forward of the trailer’s kingpin for more room between cab of truck and nose of trailer, which is a big help with short-bed trucks. Enjoy a smoother ride with a specially formulated shock-damping cushion.
The King air pin box from Airsafe utilizes four air bags tied together to reduce shock and improve ride quality. The air bags allow you to fill all from one point while transferring air between them. Air ride makes sure you experience no bounce, without rigid points allowing improved control and helping to increase the life of the trailer. The bags allow you to increase or decrease air pressure for pin rating without the need for shocks. Available for a variety of manufacturers’ pin box designs.
The Tri Glide Air Ride Pin Box by Trailair replaces the conventional rigid hitch connection between the fifth-wheel and pickup. It uses a unique scissor action that allows the air spring to absorb and dissipate road forces; the shock absorber handles the rebound effect. It helps reduce the fight between the trailer and tow vehicle, protecting your investments and damping road shock, providing a smoother ride. Available for many manufacturers and are available in a multi-fit design that can be matched up based on style, width, length and drilled on site.