Section 14 of 16
Towing Your Trailer Safely
Perform a safety inspection before each trip. Make sure that:
- The pin securing the ball mount to the receiver is intact.
- The hitch coupler is secured.
- Spring bar hinges are tight with the safety clips in place (load equalizer or weight distributing hitches).
- Safety chains are properly attached.
- The electrical plug is properly installed.
People who tow trailers share the same safety concerns as other RV drivers. However, a tow vehicle and a trailer form an articulated (hinged) vehicle which presents an additional set of concerns. The weight considerations described on pages 30 and 31 are very important to safe towing. The tow vehicle must be a proper match for the trailer. If the trailer is properly equipped, it can perform safely under a variety of driving conditions. The tow vehicle should also have enough power to climb mountain grades without excessive loss of speed. There are three basic types of trailers which mostly differ in the way they are hitched:
- Conventional travel trailers, including folding camping trailers.
- Fifth-wheel trailers.
- Motorcycle, tent, and cargo trailers.
The ball and coupler hitch is used on a wide variety of tow vehicle and trailer combinations. This hitch consists simply of a ball attached to the rear of the tow vehicle and a coupler (socket) at the tip of a tongue or A-frame attached to the front of the trailer. This hitch is commonly used on recreational trailers.
A load-distributing hitch is used for heavier models such as utility trailers, boat trailers, and travel trailers. (See the Balance and Hitch Adjustment sections) These load-distributing hitches use special equipment to distribute the tongue load to all axles of the tow vehicle and trailer to help stabilize the tow vehicle. Here are some terms you should know when discussing hitch adjustment and in evaluating hitch performance:
- Receiver: Hitch platform fitted to the tow vehicle.
- Ball Mount: A removable steel component that fits into the receiver. The hitch ball and spring bars (only on load- distributing hitches) are attached to it.
- Sway Control: A device designed to lessen the pivoting motion between the tow vehicle and trailer when a ball-type hitch is used.
- Coupler: The ball socket at the front of the trailer A-frame that receives the hitch ball.
- Spring Bars: Load-leveling bars used to distribute hitch weight among all axles of the tow vehicle and the trailer in a load-distributing ball-type hitch.
Not as much attention is given to balance, hitching procedures, and weight restrictions for fifth-wheel trailers because they are basically very stable. A disadvantage that a fifth-wheel has over conventional trailers is that much of the truck bed space is not available. The fifth- wheel hitch occupies the center of the truck bed and the hitch pin is in front of the center line of the tow vehicle’s rear axle. The hitch weight of fifth-wheel trailers is usually around 20 percent of the trailer weight. Hitches are rated for up to 15,000 pounds of gross trailer weight. Here are some terms used to describe typical fifth-wheel hitch components:
- Fifth-wheel Plate: Unit that contains the hitch plate, plate jaws, and a handle mounted in the truck bed.
- Handle: Device used to release or lock the plate jaws.
- Hitch Plate: “Wheel” that allows the trailer to rotate.
- Pin: The connecting device attached to a fifth-wheel trailer and designed to fit into the plate jaws mounted in the truck bed.
- Pin Box: Structure attached to the bottom front section of the trailer frame (the pin is attached to the bottom).
- Plate Jaws: Holds the pin.
- Side Rails: Support rails which are bolted to the tow truck bed to support the fifth-wheel hitch.
Motorcycle, Tent, and Cargo Trailers
There are several types of couplings between the towing vehicle and the trailer, which are:
- Ball and socket.
- Ball type with a swivel.
- Universal-joint type with a detachable pin.
- Pin and swivel type.
The coupling you choose should be:
- Non-slip, non-loosening, and non-binding.
- Easy to hook and unhook.
- Free moving.
Motorcycle riders towing a trailer must remember to ride closer to the center of the road. You have the width of your trailer to worry about. Be careful of the “oil strip” in the center of the road at intersections. Also, watch for uneven road surfaces and road edges which can unbalance the trailer.
Here are the rules for transporting people in RVs or recreation trailers:
- People are not allowed in a trailer coach while it is being towed (CVC §21712(d)).
- People are allowed in a fifth-wheel trailer coach while it is being towed (CVC §21712 (f), (i)).
- A camper with people in it must have an unblocked exit door which can always be opened from both the inside and outside (CVC §23129).
Weighing a Trailer
You can find a public scale by looking under “Public Scales” in the yellow pages of your local telephone directory.
Trailers must be carefully weighed to make sure that loads are properly distributed, front to rear as well as left to right. There are two additional considerations with trailer weights:
- The tow vehicle pulling the trailer.
- The hitching system that connects the two.
Both the tow vehicle and the hitching system have weight capacities which affect the safe handling of the vehicle. As a new RV owner or driver you should be aware of this.
- Tow Vehicle – do not exceed the GVWR of the tow vehicle. This includes the curb weight of the vehicle, payload, and hitch weight. Hitch weight is the percentage of the trailer weight that is placed on the trailer coupler of the tow vehicle. (Refer to the next section on Trailer Vehicle Hitch Weight.) Tow vehicles also have gross axle weight rating (GAWR) limits. The payload and hitch weight must be divided evenly between the axles to conform to the maximum weight limits and to avoid oversteering problems.
- Trailer Vehicle Hitch Weight – approximately 10-15 percent of a trailer’s gross weight is designed to be loaded in front of the front axle and onto the hitching mechanism. This ensures the stability needed for road handling. If your trailer is not stable, you may have a problem with not enough weight on the hitch. Here is a method to figure out the hitch weight:
- Park your loaded trailer on a scale so that the hitch coupler extends beyond the end of the scale, but the tongue jack post (the post on the front of the trailer which rests on the ground when unhitched) is on the scale.
- Block the trailer vehicle wheels, unhitch the tow vehicle, and obtain a weight rating. This is the curb weight of the trailer vehicle alone.
- Place a jack stand or 4″ x 4″ blocks under the coupler and beyond the scale so that the tongue jack post is supported off the scale and the trailer is fairly level. Note this weight rating.
- Subtract the reading in #2 from the reading in #3 for the hitch weight. In any RV, vehicle stability and safety can be affected by weight distribution. For example, if the rear axle weight is low, it is best to load the heaviest supplies toward the rear. Keep the heaviest supplies at the bottom of the RV, to keep the center of gravity low and ensure the best handling.
Before you tow a trailer, evaluate the trailer’s weight distribution. Hitch weights for travel trailers should typically be at least 10 percent of the trailer’s gross weight for acceptable handling. In some cases it can go to 15 percent or higher. Hitch weight for larger trailers is limited by the capacities of the tow vehicles and hitches. The strongest load- distributing hitch is rated for a maximum hitch weight of 1200 pounds. Most passenger car suspensions cannot handle that much weight and the trailer should be towed with a pickup truck or van. Improper weight distribution can cause the trailer to fishtail (sway back-and-forth across the lane).
If the hitch weight is less than 10 percent of the gross trailer weight, you can compensate for some of this by loading heavy supplies such as tools and canned goods as far forward as possible. If your trailer’s water tank is behind the axle(s), travel with as little water in the tank as possible to reduce weight in the rear. Trailers with water tanks located in front usually handle best when the tanks are full, because the water adds to the hitch weight.
Be sure that the spring bars of the load-distributing hitch are rated high enough to handle the hitch weight of your trailer, plus a safety margin of at least 10 percent. Check for adequate rear suspension of the tow vehicle. This means that the vehicle sits relatively level prior to hitching the trailer.
Load-distributing hitches are designed to distribute the hitch weight relatively evenly to all axles of the tow vehicle and trailer. The tow vehicle and trailer should be in a level position (altitude) in order for the hitch to do its job properly. Here is how to check:
- With the tow vehicle loaded for a trip, measure the distance between the vehicle and the ground at reference points, which you can establish, in front and rear. Keep the figures handy for later use.
- Hitch the trailer and adjust the tension on the spring bars so the tow vehicle remains at roughly the same attitude (i.e., if the rear drops an inch after hitching, the front should also drop an inch).
- Inspect the trailer to be sure it is level. If it is not level, the hitch ball height should be raised or lowered, as necessary. You may need spring bars rated for more weight if you cannot keep the tow vehicle from sagging in the rear.
Safety chains are required for travel trailers. Safety chains are not required for fifth-wheel trailers. The purpose of safety chains is to prevent the trailer from separating from the tow vehicle in event of a hitch failure, such as a hitch ball that has loosened. The chains should be crossed in an “X” fashion below the ball mount, with enough slack to allow unrestricted turning, but not enough to allow the coupler to hit the ground.
Breakaway switches are also required for any trailer having a gross weight of 1500 pounds or more and manufactured after December 31, 1955. They are designed to activate trailer brakes if the tow vehicle becomes separated from the trailer. One end of the breakaway switch is attached to an electrical switch on the trailer frame and the other end is looped around a stationary hitch component on the tow vehicle. If the two vehicles become separated, the cable pulls a pin inside the breakaway switch and applies full power from the trailer battery to the trailer brakes.
Even though hitch component failure is rare, the breakaway switch and the safety chains must be in good working order.
The hitch on the motorcycle trailer should be on the same plane as the rear axle on the motorcycle or slightly below. This will help prevent the trailer from pushing up on the rear end when braking. Also, the hitch should be as close to the rear tire as possible to provide a more solid support without interfering with the tire. Anchor the hitch so that two mounts are on each side. One of the two mounts on either side should resist a downward force and one of the two mounts on the other side should resist the rearward pull.
The tongue length on the trailer is generally twice the trailer wheel width but no more than six feet from the axle to the end of the tongue. Good design will allow for good sway control. If the tongue is too short, the trailer will sway. If too long, the trailer will be sluggish and cut corners when turning.
For motorcycle trailers, you should use a trailer designed for motorcycles because auto trailer tongue weights are too heavy. A trailer with a good aerodynamic design will enhance handling and performance. Maintaining a low center of gravity will improve handling as well.
The trailer should handle well if the weight and hitch adjustments are correct. However, the coupling between a tow vehicle and trailer should also prevent side-to-side motion for the best possible towing comfort and safety. If you detect sway in your trailer, stop to check if the load has shifted. Check for suspension problems and make sure the tires and wheels are secure and inflated properly. Be sure the trailer hitch is secure. A small reduction in tire air pressure or a slight increase in the tongue weight may help. A sway control device should be included when the hitch is installed. This device helps give the tow vehicle and trailer a “one-vehicle” feel. There are two basic types of sway control systems available:
- Friction bar – slides in and out and is activated by the motion of the vehicles. When you brake or turn, the trailer weight compresses the bar which then compresses the trailer against the tow vehicle.
- Dual cam sway control – usually works better for large trailers with heavy tongue weights. The cam action is applied to the spring of the trailer to reduce sway and shifts the weight forward. It also adjusts a weight shift which allows the trailer to follow the tow vehicle.
Trailers in California are required to have reflectors, tail, brake, and license plate lights. Signal lights are also required if the tow vehicle’s lights are hidden. Trailers over 80 inches wide must have clearance lights. Most manufacturers comply with these requirements; however, it is up to you to be sure that all lights operate correctly.
In California, brakes are required on any trailer coach or camp trailer having a gross weight of 1500 lbs. or more. Usually the braking capacity on tow vehicles is good; however, it may not be good enough to safely stop the several hundred to several thousand additional pounds that your trailer weighs. Most conventional and fifth-wheel trailers have electric brakes, activated by a controller in the tow vehicle. The controller automatically coordinates the tow vehicle and trailer braking so the two systems work together when the brake pedal is applied.
The controller can also be helpful in stabilizing a trailer that sways because of bad road conditions. Manually applying the trailer brakes by using the hand lever on the controller will stabilize a trailer that is likely to sway.
Folding camp trailers and boat trailers are usually fitted with surge brake systems which operate separately from the tow vehicle’s brakes.
Surge brakes are applied by a mechanism attached to the receiver/ball connection. As the tow vehicle slows, the forward motion of the trailer compresses the mechanism which in turn applies the trailer brakes.
Motorcycle trailers do not need brakes unless the weight exceeds 1500 pounds gross. If you install brakes on your motorcycle trailer, be sure the brakes do not brake harder than the motorcycle or the motorcycle may flip backwards over the trailer when the brakes are applied. The brakes must always be properly adjusted.
Backing a trailer can be frustrating for inexperienced owners. The most important thing to remember is that the trailer will go in the opposite direction of the tow vehicle. It is helpful to have another person help you back the trailer.
Here are two methods for backing trailers:
- Turn the vehicle’s wheels to the right to make the trailer go left, and vice versa.
- Put your hand at the bottom of the steering wheel. The trailer will go in the same direction your hand moves (moving your hand to the right will cause the trailer to go right, and vice versa).
Sharp steering wheel corrections will cause the trailer to jackknife and may cause damage to the rear of the tow vehicle or the front of the trailer.
This booklet gives you some important information about RV and trailer safety. A good understanding of RV and trailer safety and lots of driving practice will help you operate your vehicle with greater confidence and enjoyment.
Be safe and enjoy your travels.