Wantta Get Hitched ?

The forgotten link may be right behind you as you tow your trailer down the road. That tow hitch is every bit as important as the tow vehicle and the trailer, however it is often given the least amount the thought. No process seems more involved and protracted than the selection of a towing vehicle and the perfect trailer. We spend literately hundreds of hours researching, reading, looking, discussing and even worrying about the decision of which vehicle and trailer we want. However, we all too often go through this selection process and then when we pick-up the trailer we tell the RV dealer to “put a hitch on’er” for the tow vehicle without really considering what that means.Hitches come in three general types. The tow-bar hitch, the 5th wheel and the stock hitch. The sub-classes of each general type would take a rather large book to describe fully, but there are several basic things that fall into the “Must Know” category.

Towbar hitches come in two major types. The simple ball or weight-carrying hitch where the entire hitch weight load is placed on the ball at the rear of the towing vehicle. These are generally used for lightweight towing vehicles pulling trailers of 3,000 to 3,500 pounds GTW. Larger towing vehicles can pull higher weights but care must be taken not to exceed the vehicle manufacturers recommendations. Weight-distributing hitches come with torsion or spring bars that distribute the load from the ball forward to the frame of the towing vehicle. These hitch systems are capable of pulling up to 15,000 pounds in a class-5 receiver hitch and 1,200 pounds of tongue weight. I’ll do more on conventional hitches in a latter article, but for now let’s concentrate on 5th wheel hitches.

At one time 5th wheel hitches were mounted on the top of cars or in the trunk! That may seem strange but I’ve seen em – does that date me? Holliday Rambler even had one where the hitch was located on the pinbox, just upside down so the hitch would slide over the pin which was in the bed of the car or truck. Now they are all designed to be used with a truck type tow vehicle. The standard hitch is mounted in the bed of the truck at or just ahead of the rear axle thereby spreading the weight of the trailer the length of the truck. 5th wheel trailers tend to be more stable due to the this weight distribution and also have a much smaller turn radius than a conventional towbar trailer because the pivot point is more centered in the towing vehicle rather than located behind the rear bumper like a towbar system. The Pull-Rite draw bar hitch being the exception.

The early truck hitches were simply a bar with a hitch in the middle. The ends of the bar were on pivots located along the wheel wells in the truck bed. The bar could only pivot front-to-rear, no side-to-side motion was possible. The first time I pulled an over 30-foot trailer with one of these old hitches was kind of a shock. We left a gas station with a deep gutter between the gas station apron and the road way. The truck was twisting one way and the trailer was trying to go straight and the resulting sound was about what you might expect from a wing being torn off of an aeroplane !! These old hitches also required that the truck and the trailer be level to each other when hitching or unhitching, so leveling blocks were needed for the trailer and the truck. What a PAIN! The rocker style hitch fixed this problem by putting the hitch on a pedestal and allowing the head of the hitch to move side-to-side as well as front-to-rear.

The second type are airbag supporte systems where the weight of the trailer is supported by airbags built into the hitch or into a replacement pinbox. The rise in the use of medium duty trucks to pull larger trailers has made these hitches almost mandatory. Imagine a truck with a 19,000 pound rear axle and springs pulling a 15,000 pound trailer which is putting perhaps 1,500 pounds of pressure on the hitch. The truck hits a big bump in the road, the hitch load may jump to 6,000 pounds or more pressure but with 19,000 pound rear truck springs there is no “give” in the rear suspension of the truck so the entire shock load is transmitted to the pinbox of the trailer. The result is the same as if the trailer hit the street directly with the hitch pin -bang ! Several trailers had their pinboxes and front framework shoved up into the roof of the trailer or their pinboxes ripped off in the early days of medium duty truck use. Airbags soften the ride and prevent damage to to the hitch and truck as well as softening the ride inside the trailer.

Most 5th wheel hitches are designed for trucks with at least an eight foot bed, but the popularity of the shorter six foot bed created the need for the slider 5th wheel hitch. Picture a six-foot long truck bed with the 5th wheel hitch located over the rear axle. This puts most 5th wheel trailer noses almost touching the cab of the truck. If you make any but the most modest turn -wham! The trailer hits the cab. If you move the hitch behind the axle to provide cab clearance you are almost at the tailgate.

Remember the teeter-totter board from the kid’s playgrounds? Put weight on one end of the board and the other side rises. The same applies with offsetting the hitch to the rear of the truck bed which in effect lightens the front end of the truck with a tail-wagging-the-dog effect that won’t soon be forgotten. Slider hitches are the answer for short bed trucks. Most Sliders have an electric motor or other adjustment system built into them that the driver uses to move the hitch forward or back in the trucks bed as needed. Another type of slider (Pullrite) uses a cam system that automatically adjusts the in-bed position the hitch by reading the angle between the truck and trailer. If you are going straight the hitch moves to just behind the cab which will be at or ahead of the rear axle for proper weight balance. When you make a turn, cams in the hitch base push the the tow head back behind the axle to give clearance between the nose of the trailer and truck cab. The more angle of turn and further the hitch is pushed back. Some owners have reported better fuel mileage when using a slider because the trailer is closer to the cab of the truck when in highway mode.

If you look around RV parks you will see more and more stock hitches being used. These use a ball located in the floor of the truck bed. The stock hitch as a long tube like opening that is put over the ball. Towing capacity is up to 30,000 pounds and the ball is in effect part of the truck bed so the hitch loading is the same as the truck’s net cargo capacity. Stock hitches come in rigid mount, polyurethane cushioned or airbag models. Because only the ball resides in the truck removing it or dropping a lever that hides the ball quickly clears the bed of the truck without first having to remove a bulky hitch and rail system and then finding a place to store them.

I have a list with phone numbers and web addresses of all the major hitch makers – if you want a copy drop me a note in the comments section and I’ll send it on to ya.

Later – –

The Old Ranger