Towing a Trailer

Thousands of drivers use their cars or pickup trucks to pull a trailer. The last several years have shown a substantial increase in the purchase and use of recreational vehicles (RV’s) and trailers. This chapter of our car maintenance website can help you if you have to tow any vehicle, whether it is a small boat trailer, a carryall trailer, a tent trailer, or even a large travel trailer.

GENERAL INFORMATION

Refer to your Owner’s Manual for information and suggestions before towing any trailer. Passenger cars are designed to be used primarily as passenger conveyances, and a car used for towing a trailer handles differently, requires more frequent servicing, and costs more to operate. 

Your safety depends on avoiding overloads and using the correct equipment properly. The maximum trailer weight that any car can pull efficiently depends on the weight of the car and the special equipment installed on the car as recommended by the manufacturer. Never tow any trailer unless your car is properly equipped.

The best way to tow a heavy (2,000 pounds or more) trailer and load is with a frame-mounted, load-equalizing hitch that has sway control for stabilization. A hitch that bolts to the frame is better than a welded hitch, because welds sometimes crack or break. 

Avoid bumper hitches if possible, except on the recommendation of a reputable trailer rental agency. Do not use axle-mounted hitches, which can cause damage to the axle housing, wheel bearings, wheels, and tires. Follow the advice of your trailer dealer or a reputable installer of trailer hitches.

All trailer hitches should have two safety chains, properly attached. Many states require that the safety chains be attached to the trailer tongue between the ball and the trailer, as the ball is the most likely part to fail in case of an accident.

As a rule of thumb, the tongue load of the trailer should be no more than 10 percent of the loaded trailer weight. Shifting the distribution of the load in the trailer can vary the tongue load. The weight of the tongue load on the rear of your car means you should carry less weight inside your car, particularly in the trunk. Since you need more air pressure in your tires when your car is carrying loads, ask a tire dealer for the correct pressure, but do not put in more than the maximum pounds per square inch (psi) of pressure given on the side of the tire.

Maintenance schedules differ for cars that pull trailers. The automatic transmission should be serviced every 12,000 miles, or twice as often as with normal car use. Change the engine oil about twice as often as you normally do. Depending on the amount of the load to be pulled, the cruising speed, and the distance to be traveled, you may need to install a transmission fluid cooler; consult your automobile dealer.

Mount an ordinary ball-and-socket towing hitch on the passenger side of the front bumper of your car to maneuver a small boat trailer or other small trailers into tight spots. This tip is useful for boat launching or for turning around on narrow roads.

You may be eligible for a trucker’s discount on gas if you use a pickup truck to pull your trailer; ask about 

this discount when you buy gas.

TRAVEL TRAILERS

The following tips will be especially helpful for drivers towing large travel trailers:

Selection of Trailer and Towing Car

Trailers with tandem wheels (four wheels and two axles) have less sway and are more easily controlled on the highway. Do not use small or medium-sized cars to tow medium to large (twenty-two-foot to thirty-foot) travel trailers, or trailers that are too heavy. Check with your car dealer; too big a trailer is unsafe and places a severe strain on the smaller car’s body and engine.

You can equip a towing car with a low-ratio differential at the time of purchase or later. It causes the engine to turn faster in relation to the wheels to produce more power, but will also consume more gas when you operate the car without the trailer. An alternative is to select a car with a larger engine and a standard ratio differential.

Some trailer owners use air shocks or booster shocks on the tow car to permit the trailer and car to “level up,” which means the shocks on the back of the car can support the weight of the trailer and keep the car level. Booster shocks are especially desirable for a car with soft springs; heavy-duty springs can be stiff and may give you a bumpy ride when you are not pulling the trailer.

Trailer Hitch

Medium to heavy trailers place a heavy load on the rear of a car, and some of this weight must be shifted to the front wheels of the tow car. This weight shift involves tremendous forces in the trailer hitch and at the points where the hitch is attached to the car. 

Through the use of tension bars, weight-distributing hitches are engineered to distribute hitch weight equally to the four wheels of the tow vehicle and the wheels of the trailer. You should also install one or two sway bars, as they are essential for minimizing the sway of the trailer in poor road conditions, high crosswinds, sudden swerves, and when passing large vehicles, such as trucks.

Buy a hitch that is recommended by a reputable and experienced travel trailer dealer and have the hitch installed by a professional. Examine the hitch often during use, especially during the first few days of towing, paying particular attention to welding that may have developed cracks or other signs of failure. 

Be certain to install a break-away switch, which usually consists of a cord or fine wire strung be-tween the two halves of the hitch. When the cord or wire is broken for any reason, the trailer’s electric brakes are applied automatically. Another system operates when the cord is pulled, closing a switch that activates the brakes. Incidentally, safety chains are required in most states.

Brakes

Heavy trailers cannot be towed safely without the ability to brake the trailer wheels, thus the trailer should have electric brakes. These can be activated manually, or by means of a brake pedal switch, in which case your foot on the brake will operate the electric brakes before the car’s brake pedal moves enough to actuate the car’s brakes. Test the trailer braking system at the start of each trip after it is hooked up to the car.

Tires

The tow car’s tires should be of a high quality, in good condition, and inflated specifically for the load you carry. Radial tires are es-pecially recommended for cars pulling trailers: they are more depend-able, give more miles of service, and run cooler under loads than other types of tires. Buy the best tires you can get for your trailer if you are pulling a heavy trailer long distances.

Trailer tires do not give a readily detectable warning when they start going flat. Once flat, the tires are soon ruined if the trailer is moving. Carry a spare wheel and tire for your trailer, and do not for¬get a lug wrench for your trailer wheels. Every new trailer owner ought to practice changing a tire before he has to do so on the road.

Trailer Jack

Carry a hydraulic jack with ample capacity. With some trailers, if you use a jack under the axle to raise it enough for the bottom of the tire to clear the ground, you will have a hard time getting the spare into the wheel well and onto the hub. A better method is to raise the trailer by placing jack stands under the trailer frame at the front. Then use a hydraulic jack and some wooden blocking under the rear bumper to lift the trailer body up. The axle sags and the tire will go on or come off easily.

Wheel Bearings

Keep an eagle eye on the wheel bearings; be sure they are properly lubricated and adjusted.

Refrigeration

Some types of refrigerators must be level to operate properly. You can use a carpenter’s level in the freezer compartment or two small levels that are designed to be mounted on the outside of the trailer.

Cooling

You engine’s ability to pull a trailer of a certain weight without over-heating depends on several things: the horsepower, the differential gear ratio, the cooling system, the transmission cooling system, the speed traveled, and the terrain. A skillful driver knows the safe range of his car and stays within these limits.

Since your car engine will need to dissipate more heat when you are pulling a trailer, additional cooling capacity is a good investment with heavy trailers. You can order a car from the manufacturer with a “trailer pack,” which usually includes a heavy-duty radiator and a transmission fluid cooler; the dealer can install both if the car is not equipped at the factory. Install a water temperature gauge on your car if it has only a warning light to signal heat build-up. Slow down, turn off the air conditioner, or take other steps before the engine gets too hot and is damaged. If you are driving in the mountains, shift to a lower gear before the engine labors and strains.

Insurance

Some states require $100,000/$300,000 minimum liability insur-ance on all travel trailers. Know your coverage and the insurance laws of your state.

Things You Should Carry for Your Travel Trailer

I recommend that you carry a spare tire and wheel for your travel trailer, a lug wrench for the trailer wheels, and a hydraulic jack of sufficient capacity. Your trailer should have two levels mounted on the outside, one on the tongue end and the other on one side of the trailer. In addition to these, you should carry:

1. Four wheel chocks or blocks

2. Two stabilizer jacks (preferably four)

3. A small shovel

4. An axe

5. A tow rope, about fifty feet of %-inch or 1-inch nylon is
satisfactory

6. An assortment of small tools, adjustable wrenches, etc.

Confidence

When you first get your travel trailer, practice towing and back¬ing up on a shopping center parking lot, a school ground, or a vacant athletic field. Skillful trailer drivers are not born that way; they achieve handling skills through practice. With a properly equipped car, trailer towing is safe provided the driver is careful and confident.

Parking

You can often find a drive-through pad when parking your travel trailer. When it is necessary to back a trailer into a parking space, you will find it useful to have someone stand outside the car and direct you.

Emergencies

Emergencies and problems may arise when towing a trailer. Keep cool and use common sense, and you can probably solve the problem without undue stress or risk and little or no damage.

If your car brakes fail without warning, activate the electric brakes on the trailer. Apply them firmly with a snubbing action (which means apply brakes, then release, apply, and release). Applying the brakes constantly with no cooling interval may result in the brakes getting so hot they will no longer operate properly. 

A twenty-foot or larger travel trailer probably has enough braking capability to stop itself and the towing vehicle, if the driver handles the brakes properly. 

Simultaneously, with automatic transmission, move the gear lever into second gear, then into low. With manual transmission, keep shifting down until the towing vehicle’s speed is reduced as much as possible by using the engine as a brake.

What do you do if your brakes fade? The brakes on your car may simply fade away on lengthy downgrades that require frequent braking, a problem that is more likely to occur with drum brakes than with disc brakes. You will smell a strong odor of overheated brake linings. 

Stop your car and trailer, using the procedure already mentioned. Pull off the road and let the brakes cool for thirty minutes or longer; re¬moving the hub caps will help the hubs to cool quicker. 

Drive more slowly and in lower gears when you start again, using engine drag for a brake. At the earliest opportunity, get a reputable mechanic to check the condition of your brakes and make any needed repairs.

If you are driving up a steep incline while pulling your trailer, and your engine dies, but the emergency brake will not hold, stop the car with your foot brake, holding it down while you get someone to put wheel chocks or blocks behind the rear wheels of the trailer or the car. 

If you do not have any blocks of wood, perhaps your helper can locate rocks, logs, bricks, or other material to block the rear wheels. Spare tires and wheels can be used for chocks.

Suppose your trailer disconnects at high speed. When the weight-distributing hitch fails, the trailer tongue will probably sink to the ground, either by breaking the safety chains or by pulling down the rear of the car. Do not slam on the brakes! 

Doing so will probably snap the safety chain, and the trailer will plow into your vehicle, damaging both of them. Take your foot off the gas and manually apply the trailer brakes. 

If they are not working, you will have to coast to a stop. Gradually steer to the side of the road. If road conditions permit, drive onto the shoulder to help decrease the speed of the car and the trailer. The breakaway switch should apply the trailer brakes immediately if the trailer breaks away completely.

If you have a blowout at high speed, do not slam on the brakes! Take your foot off the accelerator and manually apply the trailer brakes. Let your car and trailer begin to slow down and get your car’s steering under control. 

Hold the wheel firmly, and gradually edge the car over to the side of the road. Try to avoid using the car brakes, and stop with the trailer brakes instead. If necessary, use the car brakes lightly and cautiously, holding the trailer brakes manually. If there is a wide shoulder, ease the car onto it. 

If there is no shoulder, use emergency flashers to warn other drivers. It is better to drive on a flat tire to get off a busy highway than to try to change a tire where heavy traffic endangers your life.