In this day and age there are a lot of aftermarket bolt on products available for toyhaulers. You can get everything from a paper towel holder to an automatic satellite TV system. The things available to upgrade your coach are endless but there is one product that the 5th wheel toyhauler owners should consider and that is a pin box.
Let’s start with what a pin box is; A pin box is the component on a 5th wheel trailer which is bolted to the trailer’s chassis with a kingpin attached towards the front that works as a coupler between the 5th wheel’s chassis and the tow vehicle’s hitch. A kingpin is the part on the pin box that actually slides into the 5th wheel’s hitch and is locked into place with the hitch jaws.
Most pin boxes are just a solid piece of steel with a kingpin on the front and some holes drilled in it so it can be mounted to a chassis. Trailer manufacturers have used this solid mount set up for years but there is a flaw. The problem is that when the tow vehicle hits a bump or is on a rough road all the force of what the truck is doing is transferred directly to the trailer through the pin box and vice versa. Also, when a truck hits a bump or defect in the road it will slow down some but the trailer doesn’t until it hits the same spot. What is happening is that the trailer is actually going faster than the truck for a split second pushing the tow vehicle then when the trailer hits the same spot it slows and pulls on the tow vehicle, this is called “chucking” and it is happening all the time.
With the new technologies of today there is a fix for this problem and 5th Airborne (Quest Technologies) has one of the best ones. Their hitch pin uses an adjustable air bag and shock absorber to suck up the force between the tow vehicle and toyhauler. It works like this; there is a pivot point at the front of the pin box so when the trailer starts moving forward on the hitch the air bag absorbs the energy and as the trailer pulls away from the hitch the shock works to control the rebound. Now almost all the “chucking” is absorbed through the 5th Airborne pin box and not the truck and trailer, thus, making for a smoother ride for both. Without all that force traveling through the whole chassis of the trailer it just stands to reason that the trailer and all the things inside the trailer will last longer.
Installing the 5th Airborne pin box is a breeze and should take you less than an hour. It is just a matter of unbolting the old pin box and bolting the new one into place, they are a direct fit. Sonny Dismuke of 5th Airborne installed mine for me and he did it in about 20 minutes. The one trick that I saw him do was use a screw driver to hold the pin box while he was putting the bolts in place. He tightens all the nuts on the pin box and then torques them to 150 ft. lbs. These pin boxes are heavy so it wouldn’t hurt to have a friend help you get it in place. Once you have the pin box installed, hook up your toyhauler to your tow vehicle on level ground and add air to the air bag until the mark on the shock is lined up with the alignment arrows and then you are done.
They have different pin boxes in stock for almost all the chassis manufacturers. Just give them a call and tell them which pin box you have. Usually the pin boxes have a part number on them for identification. If you can’t find a part number, give 5th Airborne a call and they will tell you what to measure to get the correct one. To contact Quest technologies give them a call at 866-352-7340 or check them out on the web at www.fifthairborne.com and tell them you read about it in ToyHauler Magazine.
-THM
