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What Is a Fifth Wheel to Gooseneck Adapter?

You did it! You bought your first 5th wheel, and you’re ready to drive into the sunrise on a bright new adventure. Congratulations! Now to a less glamorous purchase: the gooseneck 5th wheel adapter. 

Before buying your 5th wheel, you confirmed that your truck had the appropriate towing and payload capacities. But you’ll also need a specific type of hitch fit for hauling heavy loads, and the gooseneck adaptor could be it. 

What is a gooseneck 5th wheel adapter? Keep reading to find out!

What Is a 5th Wheel to Gooseneck Adapter? 

There are two main types of trailer hitches designed for towing heavy 5th wheel RVs. One is a 5th wheel hitch, and the other is a gooseneck hitch. The fifth wheel hitch connects to a special fifth wheel hitch you need installed in the bed of the truck. A gooseneck hitch connects to a ball in the bed of the truck that is connected to the frame of the truck.

king pin hitch
King Pin Box
gooseneck hitch
Gooseneck Pin Box

If you want to use a gooseneck hitch in the bed of your truck, but you have a standard 5th wheel king pin pinbox on your trailer, you have a few options:

  • Replace the pinbox with a gooseneck pin box,
  • Install a 5th wheel to gooseneck adapter connecting to the kingpin
  • Use a special hitch that connects to the gooseneck ball

There are a few advantages to towing on a gooseneck ball. The largest benefit is that it does not require the large fifth wheel hitch in the bed so the bed is fully usable when not towing. Towing on a ball also offers more flexibility and a very secure connection with minimal play. This frequently improves the ride quality of the truck and trailer.

How Does a 5th Wheel to Gooseneck Adapter Work? 

Various 5th wheel to gooseneck adapters work differently, but they all allow the fifth wheel to utilize a gooseneck hitch installed in the truck.

Some 5th wheel to gooseneck adapters attach directly to the gooseneck ball with an extended tube on the trailer, allowing you to attach your trailer to the gooseneck ball on your truck. These type of adapters are special metal tubes that connect directly to the kinpin on the front of the fifthwheel and reach down to connect directly to a gooseneck ball in the bed of the truck.

gooseneck 5th wheel adapter
This is a fifth-wheel to gooseneck adapter; it converts a standard fifth-wheel pin box to a gooseneck connection.

Another type of adapter is the raised ball adapter. This type is a special hitch that gets installed in the truck bed and connects to the gooseneck ball of the truck.

It then raises the ball up to a point where a small block is installed on the kingpin that allows it to connect to the ball. The most common hitches that do this are the Andersen Ultimate Fifth Wheel Connection and the Pull Rite hitch.

Andersen Ultimate Gooseneck Adapter Hitch
Andersen Ultimate Gooseneck Adapter Hitch

Lastly, a fifth wheel can be adapted to connect to a gooseneck ball by replacing the pinbox altogether.

Check out our article all about this type to learn more: What is a Gooseneck Pinbox for 5th Wheels

gooseneck pinbox
This is a gooseneck pinbox

What’s the Difference Between Gooseneck vs 5th Wheel Connection?

A gooseneck and a 5th wheel connection are very similar, but there are apparent differences. A gooseneck’s trailer tongue fits over a ball hitch in the bed of your truck. With a 5th-wheel, your vehicle must have a hinged plate hitch where you’ll attach the 5th-wheel trailer.

Both fifth wheel and gooseneck connections are more stable and decrease trailer sway compared to bumper pull connections because the trailer’s tongue weight sits over the rear axle of the truck. The stability also means you can carry a larger, heavier trailer. 

fifth wheel hitch
Traditional 5th Wheel

Are 5th Wheel to Gooseneck Adapters Safe? 

Adapters are safe if you stay underweight. For example, if you have a 12,000-pound 5th wheel and use an adapter rated to 20,000 pounds of gross trailer weight, you’ll be under the weight limit and have a safer experience. 

Gooseneck 5th wheel adapters that use the tube to connect to the kingpin can put undue stress on the trailer’s frame, however, and may even void the trailer frame’s warranty. This is because they add a torsion force on the kingpin when pulling from a low point. Seeking a professional’s advice on this matter will ensure its safe use. 

Gooseneck adapter hitches and gooseneck pin boxes do not have frame stress issues because their geometry is such that the pull force is similar to a traditional fifth-wheel connection.

andersen gooseneck adapter
This is a normal pin box with the Andersen ball connector installed on it. Note that the ball connection (the red part at the bottom) is located in the same plane as the kingpin. This means the pulling force is the same.

But while gooseneck adapters can be safe, you don’t want to cut corners. You must consider whether a gooseneck adapter is suitable for your application and, if so, which type of gooseneck adapter best fits.

Can I Convert My Standard Fifth Wheel Hitch to Gooseneck?

Yes, you can! You can use a 5th wheel gooseneck hitch and a gooseneck adapter to convert your 5th wheel to a gooseneck.

Gooseneck 5th wheel hitch

The hitch will give you a standard gooseneck ball. You’ll then set the hitch into the rails and secure them tightly using the pins. 

What Size Fifth Wheel to Gooseneck Adapter Do I Need? 

Taking measurements related to both the truck and trailer is the best way to determine what size gooseneck adapter you need. Also, know the weight of your trailer to make sure your adapter is rated for the weight you will be pulling.

For measurements, you need to consider the turning radius of the trailer and height over the bedrails of the truck.

Start by measuring from the top of your gooseneck ball to the bottom of your trailer’s kingpin plate. Make sure both your truck and trailer are situated on level ground when taking measurements.

Alternatively, if the truck and trailer are not together, measure the hitch ball and coupler heights. Next, measure from the ground to the top of the gooseneck ball and then from the ground to the kingpin plate’s bottom. The difference between those measurements will determine your adapter offset size.

Also, measure the height from the top of your gooseneck ball to the trailer making sure you have 4-6 inches of clearance over the bedrails. Use this measurement to figure out how tall an adapter you need. However, most have height adjustments of 6-8 inches included.

Consult a professional, giving him or her the measurements you’ve taken as well as details related to your truck and trailer.

What to Consider When Buying a Fifth Wheel To Gooseneck Adapter

Your trailer must ride level. Some adapters are a fixed height, while others are adjustable. The adjustable adapters are more expensive, so consider your budget when deciding what’s best.

If you decide to purchase a fixed-height adapter, identify the adapter length required for your application. Also, consider padlocks that lock the couplers as well as safety chains. You may also want to consider cushioned adapters as they tend to provide a smoother ride.

Some states require chains for gooseneck hitches, though there may be no specific reference to adapters. Still, the chains are safety items, and your safety and that of your family are paramount! 

Finally, a remote release is an excellent feature because you won’t have to climb into your truck’s bed to disconnect the hitch. A remote release lets you release the hitch using a handle attached to a steel cable.

Would You Trust a Gooseneck Adapter? 

Now that you know what a gooseneck 5th wheel adapter is, you’re better positioned to decide whether an adapter is the best option for you. If so, start measuring, obtain that professional guidance, install that adapter, hook her up, and head for the sunrise!

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About Cait Morton

Co-Founder, Logistics Queen, Business & Content Manager, and Animal Lover

An Upper Peninsula of Michigan native (aka a Yooper), Caitlin is the organization, big-picture, and content strategy queen of our operation. She keeps everything orderly and on track.

With a background in Business Management, she supports and helps channel Tom’s technical prowess into the helpful content our readers and viewers expect. That’s not to say you won’t find her turning wrenches and talking shop – RV life is a team effort. She keeps the business and the blog moving forward with a variety of topics and resources for our audience.

Believe it or not, she is rather camera shy, though she co-hosts the Mortons’ personal videos and The RVers TV show.

Caitlin’s passion lies in outdoor recreation and with animals. Some of her favorite things to do are hiking, biking, and getting out on the water via kayak, SUP, or boat.

She also loves the RV life due to the fact that you can bring your pets along. Sharing information about safely recreating outdoors with your whole family – pets included! – is very important to her. Because of this, Caitlin spearheaded the launch of HypePets in 2023.

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Fred Cook

Friday 8th of October 2021

We purchased a used 5th wheel, it was required with a goosebox on the trailer. I love it, although I was skeptical when I first saw it because of the stories that I heard of converting the 5th wheel hitch to a gooseneck connector would void the warranty. This one at the time was the only one I confirmed did not void the warranty. It takes 5 minutes to drop the ball and safety chains in the bed of my truck and at first it took a couple of extra minutes to hook up our trailer. There are air bags inside the goosebox which also improves the way the trailer rides and helps with less shaking inside the trailer.

Mortons on the Move

Wednesday 13th of October 2021

Love it! They are a great way to tow for sure!

Dennis Okey

Sunday 8th of August 2021

You are showing a picture of a flex air setup. Check with Anderson but I was told that flexair becouse it is not fixed, can change the geometry on the hitch setup and damage the Anderson hitch.

Mortons on the Move

Monday 9th of August 2021

I wonder if they changed something. We towed with that setup for 100k miles without problems but I will look into that. It does change the geometry and require backing the truck a little to get the ball off, but it really softens the ride.

Don Hagermann

Sunday 25th of April 2021

Why are you PUSHING the Gooseneck pin box? If they are so great which manufacturer puts them on their 5th wheels? Some manufacturers will void warranties for using them. Space in your truck bed should not be the issue — a quality hitch should be.

Mortons on the Move

Sunday 25th of April 2021

No Pushing, just educating as we have received a lot of questions about it. We have towed on all of them and personally, I would love to see fifth wheels come as gooseneck. Its not the majority however and probably why they never will unless custom. As for adapters yes they will void warranties and we mention that.