Thinking about upgrading your fifth wheel pin box? It's a smart move that can seriously enhance your towing experience. Whether your current pin box is showing signs of wear, you’ve upgraded to a new truck that needs a better fit, or the factory-installed model just doesn’t cut it anymore, there are plenty of reasons to consider this upgrade.
Now’s the perfect time to act, especially if you’re in the off-season. Replacing a pin box can be a little tricky, since they’re very heavy and require proper torque during installation. Whether you’re DIY-ing it or calling in a pro, it’s a good idea to give yourself enough time for the job and a few trial runs before your next trip.
Before you go plunking down good money though, it’s important to understand what exactly your fifth wheel pin box does and what types are available for your setup. This will help you determine the best option for your towing requirements. Parts Via has you covered with everything you need to know, and a selection to suit your needs.
What Exactly Does A Fifth Wheel Pin Box Do?
Let’s start with a quick refresher on the different components that allow your fifth wheel trailer to safely connect to your truck.
In the back of your truck sits the fifth wheel hitch—a big piece of metal equipment with a horseshoe-shaped plate and clamping jaws that mounts to the floor of the truck bed.
On your trailer is the pin box—a long metal component that bolts to the trailer and extends toward the truck like an arm. At the end of the pin box is a small circular piece called the king pin. The king pin slides into the horseshoe-shaped part of the fifth wheel hitch where the jaws clamp it in place, securely connecting the truck and trailer.
It’s easy to confuse the pin box and the king pin due to their similar names. However, the pin box is the entire piece connecting your truck and trailer, while the king pin is the immediate connection point. Both are key to securing your truck and trailer, but the pin box distributes the trailer's weight to the truck's rear axle.
By upgrading this pin box, you can enhance everything from pivoting movement to shock absorption. For example, a model designed to limit jerking motion will provide a smoother ride for passengers and reduce stress on both vehicles, while a rotating pin box will increase truck-trailer clearance to make tight turns easier.
Different Types of Pin Boxes
Fifth wheel pin boxes come in various sizes and styles, generally divided into short, medium, and long lengths, with adjustable telescoping options also available. The most popular lengths, based on today’s fifth wheel trailer models, are medium (15"+) and long (20̎"+).
As manufacturers continually innovate towing equipment to meet campers’ ever-evolving needs, fifth wheel pin boxes vary widely in design. However, they typically fall into one of the categories below:
- Fixed: These basic models, once installed, do not pivot or hinge. While there’s no articulation, they do offer adjustability—meaning the pin box can be moved up or down along the trailer’s nose.
- Rotating: Designed for short-bed trucks, these pin boxes position the pivot point where the box bolts onto the trailer frame, rather than aligning it with the king pin. This creates more clearance between the truck and trailer, allowing for tighter turns without the risk of hitting the truck cab with the trailer cap.
- Gooseneck: This adapter-style pin box mounts onto a fifth wheel trailer frame and provides a gooseneck coupler to connect to a gooseneck hitch.
- Shock-Absorbing: Specifically designed to provide a smoother ride, these pin boxes reduce stress from vibrations and chucking. Manufacturers use a variety of techniques for shock absorption, such as rubber isolators, gas struts, and airbags. A notable example is CURT's innovative Helux pin box, which uses coil-spring technology to enhance performance—an industry first. Since each shock-absorption method addresses jerking and jarring motions in a different way, manufacturers will often combine components in their designs. For example, the CURT Helux also integrates a gas strut.
Picking the Right Pin Box for Your Setup
Choosing the best fifth wheel pin box for your setup isn’t just about fit; it’s about finding one that complements your vehicle, meets your towing needs, and fits your lifestyle.
One of the most important factors to consider is weight capacity. Whatever pin box you choose, it must be rated to meet or exceed your trailer’s fully loaded weight, including all gear, supplies, and personal items. Exceeding a pin box’s rating poses serious risks, not only to your towing setup but also to your safety. Remember, your towing capacity is only as strong as the lowest-rated component in your system.
Clearance is another major factor. If you’re using a short-bed truck without a sliding fifth wheel hitch, a rotating pin box might be necessary to avoid interference during tight turns. Consider your truck bed size and whether you’ll need additional pivoting to keep the trailer clear of your truck cab.
Your typical travel conditions are also important. Think about where and how you tow. Do you regularly encounter bumpy or poorly-maintained roads on the way to the campground? Or is there frequent stop-and-go traffic near your destination? A pin box with shock-absorbing features can greatly improve ride comfort, reducing vibrations and jarring movements during your trips.
Finally, weigh these needs against your budget. High-quality shock-absorbing pin boxes come with higher price tags, especially those with advanced designs. Be realistic about what you need, want, and can afford.
How Do I Know If A Pin Box Is Compatible?
Once you’ve narrowed down the type or series of pin boxes that you think will best suit your setup, the next step is to ensure a secure, compatible fit.
To determine which exact pin box you need, you’ll first need to determine what type of pin box you already have. There are a few ways to do this.
- Identify the Pin Box Model: Most pin boxes have a manufacturer label with a model number (usually 3-4 digits long). Look for a sticker on your existing pin box to find this information.
- Contact the Trailer Manufacturer: If you can’t read the number or the sticker has rubbed off, try contacting the manufacturer of your trailer. They may be able to determine what make and model pin box was installed on your RV based on its VIN.
- Measure Your Pin Box Dimensions: If other options don’t work, measure the bolt hole pattern and width of your existing pin box, as well as the distance from the center of the king pin to the center of the first row of bolts. You can then compare these measurements to an online guide to find a compatible model.
Find the Best Fifth Wheel Pin Box at Parts Via
Ready to upgrade your fifth wheel setup? Parts Via has a wide selection of pin boxes, from fixed and rotating models to shock-absorbing designs that make towing smoother and safer. Explore high-quality options from brands you know and trust, like MORryde, CURT/Lippert, Reese, Gen-Y and more, and enjoy FREE shipping to a network dealer near you.