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What Is a Gooseneck Pin Box for 5th Wheel RVs?

What Is a Gooseneck Pin Box for 5th Wheel RVs?

In order to connect a 5th wheel RV to your truck, you need two things: a pin box and a hitch. While many RVers choose to tow on a traditional 5th wheel pin box and hitch, some people prefer gooseneck couplers in place of a 5th wheel receiver system.

There are many different options on the market for converting the 5th wheel to a gooseneck. One option is to change the pin box to a gooseneck pin box.

We have towed our RV on all different types of hitches and prefer the gooseneck pinbox. Let’s dig in to learn more about these coupler types, and how you can replace your 5th wheel pin box.

What Is a 5th Wheel Pin Box? 

Fifth wheel RVs are towed much differently than travel trailers. Instead of being pulled along from the bumper of your truck, you tow a 5th wheel from the bed of the truck.

First, we need to understand what a pin box is. The pin box is an engineered steel box that bolts to the front of the trailer frame. The pin box contains the coupling system that attaches the trailer to the tow vehicle.  

There are several types of 5th wheel pin boxes that differ in design, suspension, and coupler type. Solid units are lower cost and do the job. However, others provide cushioning in various ways, from rubber cushions to airbags. Naturally, the latter will give a better ride and feel for the tow unit. 

traditional 5th wheel pin box
Traditional 5th wheel king pin box

As for the connection type, the two main types of pinboxes (excluding adapters) are traditional king pins and gooseneck pin boxes. A traditional 5th wheel pin box contains a king pin on the bottom of the pin box. The king pin connects the trailer to the 5th wheel hitch by sliding into the hitch’s u-shaped receiver.

hitching with a traditional fifith wheel hitch

A gooseneck pin box connects the 5th wheel to a ball hitch in the bed of the truck. Let’s look at how this works a bit more closely.

What Is a Gooseneck Connection and Hitch? 

The name “gooseneck” comes from the type of trailers that employ this connection. The trailer’s neck goes over the tailgate, into the bed, and resembles that of a goose’s neck. Hence the name gooseneck! Most gooseneck trailers are designed to haul equipment or livestock and are easy to connect and disconnect. 

gooseneck trailer
Gooseneck trailer

A gooseneck hitch is an assembly that mounts under the bed of a truck and is bolted directly to the frame rails. It contains a 2 5/16″ ball that protrudes through the floor of the truck bed. The gooseneck part of the trailer connects to the ball. Most gooseneck hitches allow for easy removal of the ball, so the bed is entirely unobstructed when not pulling a trailer. 

Gooseneck balls are typically rated at 30,000lbs or higher towing ratings, which is great for heavy equipment trailers.

What Is a Gooseneck Pin Box? 

The gooseneck pin box is similar to a 5th wheel pin box in that it bolts to the frame of a 5th wheel trailer. Where they differ dramatically is in the coupling style. Earlier in the article, we learned that a traditional 5th wheel pin box uses a king pin to attach to a 5th wheel hitch.

gen-y pin box

A gooseneck pin box utilizes a coupler that connects directly to the 2 5/16″ gooseneck ball in the tow vehicle.

Gooseneck pin boxes are available in different configurations that can provide excellent ride quality thanks to manufacturers’ various dampening techniques. 

Are Fifth Wheel Gooseneck Adapters Safe?

Yes, it’s safe to use a fifth wheel to gooseneck adapter to tow a 5th wheel trailer. However, not all adapter designs are a permanent solution.

Gooseneck adapter for 5th wheel hitch

Permanent solutions include a complete gooseneck pin box replacement, 5th wheel hitches that rest in the gooseneck ball hole, or 5th wheel hitches attached to the gooseneck ball.

Adapter tubes that bolt or attach to the king pin on one end and a gooseneck ball on the other are only temporary solutions. You can tow a 5th wheel with these in a pinch, but extended use can cause undue stress on the trailer frame and pin box. Not to mention, it can void the warranty on your trailer frame in some cases. 

Benefits of a Gooseneck Pin Box for 5th Wheel RVs

One of the significant advantages of converting to a gooseneck pin box from a traditional 5th wheel is the truck bed’s space. Because no heavy fifth wheel hitch is needed the bed of the truck is much more accessible whenever you unhitch. There is even more room in the bed when connected as there is no hitch. Another advantage is that many heavy-duty trucks may already have a gooseneck ball hitch installed. 

reese gooseneck pin box on 5th wheel rv
Gooseneck pin box that connects directly to gooseneck ball hitch in bed of truck

Even if your tow rig doesn’t have a gooseneck hitch, they’re generally less expensive than installing a 5th wheel hitch, which leaves more money in your pocket.

In some cases a gooseneck pinbox may even save weight as a fifth wheel hitch can weigh hundreds of pounds. A gooseneck pinbox is a bit heavier than a traditional pinbox but usually less than the entire hitch system.

Lastly a gooseneck pinbox is a much better way to tow on a gooseneck ball than using an adapter tube. This is because the pinbox is much stronger and angles down to the ball. This will significantly reduce frame stresses on the fifth wheel and can be a long-term towing solution.

Replacing Your 5th Wheel Pin Box With A Gooseneck Pin Box

When shopping for a 5th wheel RV, you often don’t get much choice on the pin box that comes with it. Fortunately, it is possible to swap pin boxes for other styles. Just be warned: they are heavy!

We decided to replace our Trail Air 5th wheel pin box with a gooseneck pin box so we could utilize the space in the bed of our truck. Fortunately, we had a friend with a forklift!

using a forklift to remove a 5th wheel pin box
Using a forklift to replace our 5th wheel pin box

We first had to remove the old pin box by unbolting it from the steel plates attached to the RV. The forklift held the pin box while we loosened the bolts, then lowered it safely away.

Removing the 5th wheel pin box in preparation to install the gooseneck pin box
Removing the 5th wheel pin box in preparation to install the gooseneck pin box

Once we removed the old pin box, we loaded up the new one and did everything in reverse to install it.

Gen-Y Gooseneck Pin Box on forklift prior to installation
Gen-Y Gooseneck Pin Box on forklift prior to installation
gooseneck pin box installed on 5th wheel rv
Gooseneck pin box installed!

Best Gooseneck Pin Box: Gen-Y Fifth Wheel King Pin to Gooseneck Conversion Pin Box

We chose the Gen-Y Executive Gooseneck conversion pin box as the best because of its remarkable features and design. The pin box features the Gen-Y patented TORSION-FLEX technology. TORSION-FLEX works to isolate the trailer from the tow vehicle resulting in a safe and smooth towing experience. That means less bucking, chucking, and surging without the need for an airbag.

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Additional features include a built-in mechanical tongue weight scale and a 5-year warranty on moving parts with a limited lifetime on all others.

Models are available for up to 30k lbs in towing capacity and 5.5k tongue weight and it is important to select the correct hitch for your needs.

We installed our unit in October 2020, and we’ve found the towing experience similar to the Trail Air suspended pin box ride – smooth and solid.

The biggest benefit we’ve loved is the extra space in the bed of the truck. While towing we have more room around where our old hitch would have been. Once detached, we have the entire bed of the truck available to us.

Reese Gooseneck RV Coupler

The other gooseneck RV pin box you’re likely to see is the Reese Goose Box RV Coupler. This model was the first gooseneck pin box approved by 5th wheel manufacturers and endorsed by Lippert Components – a very big RV components supplier.

The Goose Box includes air suspension and shock absorbers to control the rebound. It will offer more front-to-back suspension but less up-and-down. Air bags are known to give a very soft ride but require maintenance. This king pin is known to be somewhat difficult to remove from the ball, but another option for gooseneck hitch towing of your 5th wheel.

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Improve Ride Quality and Increase Bed Space With A Gooseneck Pin Box

Whether you’re shopping for a new 5th wheel camper or already own one, a gooseneck pin box is an option you should consider.

We all know that storage space is at a premium when it comes to traveling full-time or even as a weekend warrior. Utilizing a gooseneck pin box gives you the freedom you need and doesn’t obstruct the bed of your truck like a substantial 5th wheel hitch. 

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Tom & Caitlin Morton of Mortons on the Move gave up the stationary life for one where they are constantly on the move. They are full-time travelers, television hosts, and digital media producers.
They left their jobs, sold their house and possessions, and hit the road in September 2015 in their full-time “home on wheels”. Since then they have traveled the US, Canada, and even internationally by RV.
Now, they are Discovery Channel & PBS TV Co-stars of The RVers, producers of “Go North” on Amazon Prime, co-founders and instructors of RV Masterclass, and contributing authors for and an Arizona travel guide.

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Sunday 11th of April 2021

We have owned an 8800 lb. 5th wheel with a goose neck adaptor for the last ten years and have towed it throughout the southwest during this time with no problems and a great ride from highways on vacation to off-road mountains on hunting and fishing trips. I never installed the fifth wheel hitch that came with the trailer because my 2006gmc came with the turnover ball already installed so ok just bought the goose neck adapter and after easy installation, drove away. Currently we are looking for a new fifth wheel and have been told by dealers that the gooseneck adaptor will void the warranty. Haven't considered changing the pin box but will look into it after reading your article as we've had a great experience with the gooseneck system, ease of use, ride, etc. Thank you,

Mortons on the Move

Sunday 11th of April 2021

Glad you found this helpful, yes that is a common complaint with the adapters. We love the kingpin replacements tho. And your right, towing on the ball in my opinion is way better :)