Hitch systems, towing packages, tongue weight, and driving permits—there’s

a lot more to towing a trailer than just hitching up and taking off down the road. This

 

tutorial provides general information and tips hat can help you make safe decisions

 

when purchasing and driving a tow vehicle and trailer for noncommercial, personal use.

 

It covers the following topics:

 

How the size and weight of a trailer affect the selection of a tow vehicle

 

Things to consider if you already have a tow vehicle

 

The importance of trailer manufacturers’ tow ratings

 

How to measure the weight of a trailer

 

The hitching, braking, and wiring systems that connect tow vehicles with trailers

 

Tire safety

 

Proper loading and weight distribution of cargo and equipment

 

State and local requirements for towing a trailer

 

A pre-departure checklist

 

Safety tips for driving with a trailer

 

Safety tips for maintaining a tow vehicle and trailer

 

Most SUVs, pickup trucks, vans, minivans, and passenger cars can be equipped to tow a trailer. However, the selection of an appropriate tow vehicle and the proper

 

equipment to tow a trailer depends on the type of trailer, its size and weight, and the

 

amount of weight being towed. There are numerous types of trailers, but in general they

 

fall into four categories: flatbed or open trailers, boat trailers, enclosed trailers, and

 

recreational vehicle trailers (including travel trailers, fifth-wheel trailers, and folding

 

camping trailers).  Check the owner’s manual and review the manufacturer’s guide to

 

see if the vehicle you plan to buy can tow a trailer. After you have reviewed the vehicle

 

capabilities, you also must investigate the capabilities of compatible hitch systems for

 

the vehicle. This is especially important if you plan to purchase a hitch from a source

 

other than the vehicle manufacturer.  You may find that vehicle manufacturers offer

 

specially designed towing packages that define the equipment necessary to tow different

 

types of trailers depending on their fully loaded weight and size. A towing package may

 

include a heavyduty radiator, battery, flasher system, alternator, suspension, and

 

brakes, as well as an engine-oil cooler, transmission-oil cooler, wiring harness, specific

 

axle ratio, and special wheels and tires.  Towing packages also may include the trailer

 

hitch receiver, which is mounted to the tow vehicle, but towing packages rarely include

 

the draw bar, or ball mount and hitch ball. The draw bar is a separate assembly on

 

which the hitch ball is mounted. The draw bar then slides into the hitch receiver on the

 

tow vehicle and is secured with a locking pin. The front part of the trailer that hitches to

 

the tow vehicle is referred to as the tongue. At the end of the tongue is a coupler into

 

which the hitch ball is inserted and secured.  A manufacturer may offer different towing

 

packages to safely tow various sizes and types of trailers. Towing packages indicate

 

both equipment that must be installed on your tow vehicle and equipment that is optional

 

or recommended. For example, not all trailers require the tow vehicle to be equipped

 

with extended side-view mirrors. But extended side-view mirrors. But is wider than your

 

tow vehicle, you will need extended side-view mirrors to see rear- and

 

sideapproaching traffic.

 

If you already have a tow vehicle, look up its tow rating—size, maximum loaded weight, and maximum tongue weight of a trailer that the tow vehicle is capable of towing.

 

The vehicle owner’s manual contains these specifications.

 

Most automotive manufacturers and dealerships have towing specification guides with

 

tow ratings and detailed information if extra equipment is needed to tow a trailer. While

 

your vehicle may have certain tow ratings, remember you must have a matching hitch

 

system that can handle the same specifications. To ensure safety, you may have to

 

install extra towing equipment.

 

Manufacturers’ Tow Vehicle Ratings

 

Manufacturers’ tow vehicle ratings address tongue weight as well as the individual,

 

combined, and fully loaded weights at which a tow vehicle can safely tow a trailer. They

 

also can be used to guide the selection of brake and hitching systems as well as tow

 

vehicle tires. Together with the hitch system specifications, these weight considerations

 

will help you purchase a safe tow vehicle. In general, manufacturers provide tow ratings

 

for the maximum

 

• Amount the tow vehicle may weigh when fully

loaded, or gross vehicle weight rating (GVWR).

 

• Weight a vehicle can tow. This figure may vary depending on the vehicle’s equipment,

 

Such as a manual or automatic transmission and whether it is equipped with four-wheel

 

drive.

 

Permissible combined weight of the tow vehicle, trailer, passengers, equipment, fuel,

 

etc., that the vehicle can handle, or gross combination weight rating (GCWR).

 

• Weight a single axle can carry, or gross axle weight rating (GAWR).

 

Measuring the Weight of a Trailer

 

Some manufacturers provide a “dry” or empty weight for trailers; however, to select a

 

Proper tow vehicle and hitching system, you must know how much your trailer weighs

 

fully loaded. For example, if you are towing an open trailer that carries a boat or

 

motorcycle, the fully loaded weight includes the weight of the trailer with the boat or

 

motorcycle and any additional items being towed, such as fuel tanks, motors, and safety

 

equipment.

 

  

Develop a realistic estimate of the total weight of your trailer. The time you spend doing

 

this and getting properly equipped will save you time and money in preventing

 

unexpected repairs to your tow vehicle and unanticipated breakdowns while on the road.

 

In addition to speaking with dealers and other individuals who sell and use trailers, the

 

best way to know the actual weight of your trailer is to weigh it at a public scale.

 

Manufacturers consider the loaded weight of a trailer when specifying tongue weight—

 

the amount of the trailer’s weight that presses down on the trailer hitch. Too little tongue

 

weight can cause the trailer to sway. Too much tongue weight can cause many

 

problems, including not enough weight on the front wheels of the tow vehicle.

 

When this occurs, the tow vehicle will be less responsive to steering. A weight-

 

distributing hitch can remedy this problem by transferring weight to the front axle of the

 

tow vehicle. Manufacturers also establish the gross axle weight and provide a rating that

 

denotes the maximum weight a single axle can carry. Knowing these weights will help

 

you when it is time to load your trailer. Remember that the gross axle weight rating listed

 

on the tow vehicle’s certification label must not be exceeded.

 

 

 

Tow vehicles and trailers must be compatible with hitching, braking, and wiring systems to ensure safety.

 

Hitching Systems

 

The trailer towing industry has developed a classification system that differentiates

 

hitches according to the amount of weight they can tow. This system addresses tongue

 

weight and total weight. Keep in mind that within each classification are numerous

 

hitches made by a variety of manufacturers.

The three most common types of hitches are the weight-carrying hitch, the weight-

 

distributing (or load equalizer) hitch, and the fifth-wheel hitch, or gooseneck. Weight-

 

carrying hitches are designed to carry all of the trailer’s tongue weight. Weightdistributing

 

hitches are used with a receiver hitch and special parts that distribute the tongue weight

 

among all tow vehicle and trailer axles. Fifth-wheel hitches are designed to mount the

 

trailer connection in the middle of the truck bed. When purchasing a hitch, use the

 

recommendations of the manufacturer of the tow vehicle and trailer based on the type

 

and weight of the trailer. Make sure the hitch has provisions for the connection of safety

 

chains, which are required by most states. When connected, safety chains should have

 

some slack to permit sharp turns but should not drag on the road. In addition, they

 

should cross under the trailer tongue to help prevent the tongue from dropping to the

 

road in the event the trailer separates from the tow vehicle.

 

Braking Systems

 

The selection of a brake system also will depend on your tow vehicle and the type and

 

fully loaded weight of your trailer. For a trailer with a loaded weight of more than 1,500

 

pounds, many states require a separate braking system and a breakaway switch,

 

located on the tongue of the trailer, to activate the trailer brakes in the event the trailer

 

separates from the tow vehicle. There are two basic types of brake systems designed to

 

activate the brakes on a trailer:

 

• Electronically controlled brakes usually provide automatic and manual control for trailer

 

brakes. They require that the tow vehicle be equipped with a controlling device and

 

additional wiring for electrical power. These brakes typically have a control box installed

 

within reach of the driver and can be manually or automatically applied. The control box

 

may require adjustment or“tuning in” for variations in trailer load

 

• Surge brakes are independent hydraulic brakes activated by a master cylinder at the

 

junction of the hitch and trailer tongue. These brakes are not controlled by the hydraulic

fluid in the brake system of the tow vehicle. Note: The hydraulic system of the tow

 

vehicle should never be directly connected to the hydraulic system of the trailer. These

 

systems are self-compensating and do not require adjustment for variation in trailer load.

 

Follow the tow vehicle manufacturer’s recommendations for brake selection. Some

 

states require braking systems on all axles of the trailer. So, check your state’s

 

requirements by contacting the motor vehicle administration.

 

Wiring Systems

Federal law requires trailers to have taillights, brake lights, side marker lights, turn

 

signals, and side and rear reflectors. Some trailers also have backup lights. To provide

 

power to these lights, a four-way (or more) connector is hooked into the tow vehicle’s

 

electrical system. Many tow vehicle manufacturers offer a 7-way connector that may

 

include an electric brake signal, power supply, and backup lights, in addition to the

 

typical four functions. Note: You must ensure that the signals on the electrical connector

 

of the tow vehicle match the electrical connector of the trailer. Because the wiring

 

systems of many tow vehicles use separate wires for turn signals and stop lights, you

 

may need to purchase a taillight converter. This converter will combine these wires so

 

that they can be connected to the trailer lighting system. Most factory-installed towing

 

packages include a trailer wire harness that will perform this function if required. If you

 

tow more than one type of trailer, you also may need to purchase an adapter to

 

accommodate differences in the wiring systems

 

 

All your trailer tires should be the same type, size, and construction—do not mix biasbelted and radial tires. In selecting tires for your trailer, buy the size, type, and load

 

range found on the trailer’s certification label or in the owner’s manual. Keep in mind that

 

tires have a load rating that indicates the amount of weight they can carry safely. As with

 

your tow vehicle always maintain proper tire pressure and replace worn tires.

Remember—your tow vehicle tires may require a higher tire pressure for towing,

 

especially heavy loads.

 

Your ability to handle and control your tow vehicle and trailer is greatly improved when the cargo is properly loaded and distributed.  Refer to your tow vehicle and trailer

 

owner’s manuals to find out how to

 

• Balance weight from side to side

 

• Distribute cargo weight evenly along the length

of the trailer

 

• Secure and brace all items to prevent them

from moving during travel

 

• Adjust the height of the tow vehicle/trailer

interface

 

• Apply load leveling (weight distributing hitch

bars)

 

Most trailers and tow vehicles should be level (parallel to the ground) during travel.

 

Check the instructions from your trailer manufacturer to make sure this is correct for your

 

combination of vehicles.

 

 

States and municipalities may require special permits and licenses based on the

size and weight of your trailer, especially if it is over eight feet wide. Some states require

 

additional equipment for the tow vehicle, such as side- and rear-view mirrors. Inquire at

 

your local motor vehicle administration to find out what requirements affect you.

 

If you plan to travel in another state, don’t forget to check its requirements also. For

 

example, surge brakes may not be legal in some jurisdictions. In addition to licenses and

 

permits, there may be weight, height, and width limits for using certain roads, bridges,

 

and tunnels. Also, be aware of restrictions regarding the transport of propane gas and

 

other volatile gases or fuels in tunnels. And don’t forget to contact your insurance

 

company to make sure you have the proper coverage.

 

 

PRE-DEPARTURE

SAFETY CHECKLIST

Before driving, make sure your vehicle maintenance and trailer maintenance are current.

 

This is very important because towing puts additional stress on the tow vehicle.

 

Check and correct tire pressure on the tow vehicle and trailer. Make sure the wheel lug

 

nuts/bolts on the tow vehicle and trailer are tightened to the correct torque. Be sure the

 

hitch, coupler, draw bar, and other equipment that connect the trailer and the tow vehicle

 

are properly secured and adjusted. Check that the wiring is properly connected— not

 

touching the road, but loose enough to make turns without disconnecting or damaging

 

the wires. Make sure all running lights, brake lights, turn signals, and hazard lights are

 

working. Verify that the brakes on the tow vehicle and trailer are operating correctly.

 

Check that all items are securely fastened on and in the trailer. Be sure the trailer jack,

 

tongue support, and any attached stabilizers are raised and locked in place. Check load

 

distribution to make sure the tow vehicle and trailer are properly balanced front to back

 

and side to side. Check side- and rear-view mirrors to make sure you have good

 

visibility. Check routes and restrictions on bridges and tunnels. Make sure you have

 

wheel chocks and jack stands.

 

SAFETY TIPS FOR

DRIVING WITH A TRAILER

 

Take time to practice before driving on main roads and never allow anyone to ride in or

 

on the trailer. Before you leave, remember to check routes and restrictions on bridges

 

and tunnels. Consider the following safety tips each time you drive with a trailer.

 

General Handling

 

Use the driving gear that the manufacturer recommends for towing. Drive at moderate

 

speeds. This will place less strain on your tow vehicle and trailer. Trailer instability

 

(sway) is more likely to occur as speed increases. Avoid sudden stops and starts that

 

Can cause skidding, sliding, or jackknifing. Avoid sudden steering maneuvers that might

 

create sway or undue side force on the trailer. Slow down when traveling over bumpy

 

roads, railroad crossings, and ditches. Make wider turns at curves and corners. Because

 

your trailer’s wheels are closer to the inside of a turn than the wheels of your tow vehicle,

 

they are more likely to hit or ride up over curbs. To control swaying caused by air

 

pressure changes and wind buffeting when larger vehicles pass from either direction,

 

release the accelerator pedal to slow down and keep a firm grip on the steering wheel.

 

Braking

 

Allow considerably more distance for stopping. If you have an electric trailer brake

 

Controller and excessive sway occurs, activate the trailer brake controller by hand. Do

 

not attempt to control trailer sway by applying the tow vehicle brakes; this will generally

 

make the sway worse. Always anticipate the need to slow down. To reduce speed, shift

 

to a lower gear and press the brakes lightly.

 

Acceleration and Passing

 

When passing a slower vehicle or changing lanes, signal well in advance and make sure

 

you allow extra distance to clear the vehicle before you pull back into the lane. Pass on

 

level terrain with plenty of clearance. Avoid passing on steep upgrades or downgrades.

 

If necessary, downshift for improved acceleration or speed maintenance. When passing

 

on narrow roads, be careful not to go onto a soft shoulder. This could cause your trailer

 

to jackknife or go out of control.

 

Downgrades and Upgrades

 

Downshift to assist with braking on downgrades and to add power for climbing hills.

 

On long downgrades, apply brakes at intervals to keep speed in check. Never leave

 

brakes on for extended periods of time or they may overheat. Some tow vehicles have

specifically calibrated transmission tow-modes. Be sure to use the tow-mode

 

recommended by the manufacturer.

 

Backing Up

Put your hand at the bottom of the steering wheel. To turn left, move your hand left. To

 

turn right, move your hand right. Back up slowly. Because mirrors cannot provide all of

 

the visibility you may need when backing up, have someone outside at the rear of the

 

trailer to guide you whenever possible. Use slight movements of the steering wheel to

 

adjust direction. Exaggerated movements will cause greater movement of the trailer. If

 

you have difficulty, pull forward and realign the tow vehicle and trailer and start again.

 

Parking

Try to avoid parking on grades. If possible, have someone outside to guide you as you

 

park. Once stopped, but before shifting into Park, have someone place blocks on the

 

downhill side of the trailer wheels. Apply the parking brake, shift into Park, and then

 

remove your foot from the brake pedal. Following this parking sequence is important

 

to make sure your vehicle does not become locked in Park because of extra load on the

 

transmission. For manual transmissions, apply the parking brake and then turn the

 

vehicle off in either first or reverse gear. When uncoupling a trailer, place blocks at the

 

front and rear of the trailer tires to ensure that the trailer does not roll away when the

 

coupling is released. An unbalanced load may cause the tongue to suddenly rotate

 

upward; therefore, before uncoupling, place jack stands under the rear of the trailer to

 

prevent injury.

 

MAINTENANCE

 

Tow vehicles often have more frequent maintenance requirements, including changes

 

of engine and transmission oils and filters, lubrication of components, and cooling

 

system checks. Check your owner’s manual for information on scheduled maintenance

 

of your tow vehicle and trailer. Here are some additional maintenance suggestions.

 

Tires

Periodic inspection and maintenance of tow vehicle and trailer tires and wheels are

 

Essential to towing safety, including spare tires. Proper tire pressure affects vehicle

 

handling and the safety of your tires. You can find the correct tire pressure for your tow

 

vehicle in the owner’s manual or on the tire information placard. Underinflation reduces

 

the load-carrying capacity of your tow vehicle or trailer, may cause sway and control

 

problems, and may result in overheating, causing blowouts or other tire failure.

 

Overinflation causes premature tire wear and affects the handling characteristics of the

 

Tow vehicle or trailer.

 

Brakes

 

On a regular basis, have the brakes on both vehicles inspected. Be sure that necessary

 

adjustments are made and any damaged or worn parts are replaced.

 

Hitch

 

Check the nuts, bolts, and other fasteners to ensure that the hitch remains secured to

 

the tow vehicle and the coupler remains secured to the vehicle and the coupler remains

 

secured to the trailer. The connection point may require periodic lubrication to permit

 

free movement of the coupler to the hitch ball.

 

Wiring

 

Make sure connector-plug prongs and receptacles, lightbulb sockets, wire splices, and

 

ground connections are clean and shielded from moisture. Lightly coat all electrical

 

terminal connections with nonconducting (dielectric), light waterproof grease.

 

Clean the prongs with very fine sandpaper, being careful not to damage the contact

 

area. Clean the surface deposits in the connector holes. (Make sure the lights are off to

 

prevent blowing a fuse.) Try to clean off only the deposits and lubricate lightly with

 

dielectric, light waterproof grease.