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How a Fifth Wheel Connects to a Truck

Fifth-Wheels weigh a whole lot more than a smaller trailer, and many wonder about how does it even connect. When I considered buying my first Fifth-Wheel we found out and I wanted to share my findings.

How does a fifth wheel connect to a truck? A Fifth-Wheel connects to the truck through a new hitch. Rather than a ball hitch, a horseshoe shaped piece called the fifth-wheel that first connects to the bed of your truck then connects to a piece called a King Pin that connects the truck to the trailer.

The Hitch

There is a special hitch that is necessary to buy when you move from a trailer to a Fifth Wheel. It connects to the inside of the truck bed to make a more secure pull, to allow the truck to carry more weight, and to make it easier to turn with the truck.

The Hitch is mounted into your truck by either yourself or a professional. And has a skid plate that allows the kingpin to couple (couple is the term used instead of connect) properly. It locks the kingpin in, and the skid plate allows the Fifth-Wheel motion for turns.

King Pin

The Kingpin is the connecting piece that is already a part of your trailer. It hangs from the front of all Fifth-Wheels. It is essential that you keep your kingpin lubricated for the longevity of your Fifth-Wheel.

This piece is controlled on an outside panel of the fifth wheel. It controls the height of the kingpin. When you are coupling it you can lower it to easily connect to your vehicle and it raises to stay safe from the outside elements. Make sure your kingpin is protected, they can be really hard to replace, because they are connected to your fifth wheel.

How to Connect the Fifth-Wheel to the Truck

So after your hitch is mounted into your truck, it is time to connect your Fifth Wheel. Before you begin make sure you have…

  • proper grease for your kingpin/slid plate
  • wheel chocks (stopping blocks)
  • another person to drive the truck,
  • hitch lock

When you are coupling your Fifth Wheel makes sure you are on level, hard, ground to make this an easy process and to ensure a secure attachment. Now it is important that your bed and fifth wheel are at the right height. Look for a few measurement points, making sure your trailer is at surface level.

You can adjust the head of the fifth wheeler to match the truck bed. Making sure that your kingpin is high level with the hitch for a clean connection. You can do this by, having it at the level the tailgate would be. Then before you move your truck lowering the tailgate. You can also adjust your hitch around two to three inches if necessary.

Have a friend handy!

Now it is time to open your hitch to the coupling postion, unlock it and make sure that the mouth is open and ready for the kingpin. Now once you have greased everything up. Have your friend slowly back up the truck, until the kingpin is about 4 inches away from the hitch. At this time double check that everything is level and good to go.

Now you can go raise your kingpin to the proper height. You want the head above the kingpin less than an inch above where the mouth of the hitch will be.

Caution: If your kingpin attaches from too high of an angle this will not create a secure hold. It also has the chance to ruin your hitch or the pin. Make sure it does not come too far of a side angle as well.

If you do this properly, the mouth of the hitch will automatically close around the kingpin. Then you need to move the hitch into the locked position. Then park your car (with the emergency brake) and do a visual examination of the vehicle.

Pull Test

This is a necessary step. Make sure that everything is where it needs to be and securely done. Plesae do not skip this step no matter how many times you have connected your Fifth-Wheel.

  • Initiate trailer’s manual brake
  • Taking off trucks emergency brake
  • Accelerate a little bit

If you do not feel resistance from your fifth wheel break. That means that it was not properly coupled and you will need to follow the steps again.

Final Set-Up Steps

Other things you will need to do after your trailer is hooked up to the hitch is to connect the trailer’s electrical harness to the truck then attach the lanyard of the electrical breakway as well.

  • Close tailgate
  • Remove the wheel chocks,
  • Raise the lifting jacks on the front of the fifth wheel
  • Check turn signals on trailer
  • Check brake lights

If all of these things are working you are good to go! Be careful driving off. If it is your first time, drive around a familiar unpopulated area to get the feel of the trailer. If you are going up mountains look for routes that have the most gradual incline and the widest roads. You are taking on a big feat of towing such a large piece of machinery.

Price Point

Fifth wheel hitches vary in price according to how heavy your fifth wheel is. It is usually somewhere between 600 to 2,000 dollars. And this is for the hitch, not all include the installatio kits. If you are installing this yourself be aware of that.

When you are looking for your hitch, know the weight of your fifth wheel. I cannot say that enough. But besides that, witch hitch you get depends on what you want. There are many different brands to choose from.


Installing your hitch is a lot harder than just changing your ball hitch on a normal truck. It needs to be mounted in the back of your truck. You have a few options on how you can do this. Whether you want to do it yourself or not.

Personally Installing

If you plan on installing the hitch yourself you will need to have these items on hand.

Depending on the size of your trucks bed, you will need to measure, where the hitch should be installed. If it is a short bed it should be 39 inches back from the cab, if it is a long bed 56 inches. Mark that measurement, because that is where your bolt will be.

Then measure 26 5/16 inches from the tailgate and mark that. It is where you will drill the hole for the fifth wheel rear rail will be. (If there are not holes already)

Line up the bolts and holes to the fifth wheel hitch. Install the front rail bolt from underneath. Install the nuts in the front and rear to secure the fifth wheel.

If you have a short bed you will need to install an extender. This will add about twenty inches to the pin-box to the kingpin. This will give you the room you need to get that full turn radius that comes from the fifth wheel.

Outsourcing to have it installed

If you do not own these things yourself, if building things is not your strong suit, or if you just want to be extremely careful. Most automotive shops will be able to do this for you. Some shops will have access to great hitches that they personally recommend. But you can still go out and buy your own hitch for them to install.

When you are buying your fifth wheel, sometimes you can have them sweeten the deal with a fifth wheel hitch and installation. Some dealers will do this for you.

Related Questions:

Why is it called a Fifth Wheel?It is called a fifth wheel because like a horse drawn carriage, it has a coupling device that allows the axels to pivot on the horizontal plane, to allow turning. This is the extra wheel that is found in the hitch. It allows it to move in an entirely new way.

What truck do I need for pulling a fifth wheel?You are going to need a one-ton truck, that has an 8-foot long bed. It needs to have a large diesel engine. There are many different brands of the truck that works, but they need to fit these requirements.

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