Trailer Towing Tips & Terms
The weight rating
of trailer hitches, receivers, ballmounts, balls, and safety chains (or any
other piece of the towing system) must not be exceeded by gross trailer weight
or tongue weight.
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GROSS
TRAILER WEIGHT (GTW) -
the weight of the loaded trailer. To determine
GTW, weigh the loaded trailer on a vehicle scale. |
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TONGUE
WEIGHT (TW) - the
downward pressure placed on the ball by the coupler. Normally the TW
can be measured using a bathroom scale and a box. On a level surface,
place the coupler of the loaded trailer on the scale at normal towing height
(not pictured). For heavier
tongue weights, use the method diagramed on the right. |
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Trailer Loading - One of the main causes of trailer sway
is not having a large enough percentage of trailer tongue weight compared to
gross trailer weight. Usually tongue weight is 10 to 15 percent of the
trailer's gross weight. To help prevent the trailer from swaying back and
forth, a few things can be done. Try placing heavier cargo in the front of
the trailer, ahead of the trailer's axle. Also center the cargo
left-to-right and use tie-downs to keep the load from sliding.
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Trailer Sway
can lead to a loss of vehicle control. When starting out with a new
load on a trailer, make sure it will not sway by gradually increasing your
speed in intervals until highway speed is reached. If the trailer does
begin to sway, try adjusting the cargo and equipment accordingly and then
repeat the test. If repositioning the load and equipment did not help reduce
the sway, a sway control devise may be needed. |
Driving - The addition of a trailer adds weight
and length to the tow vehicle. More weight means more time to speed up
and more importantly, slow down. Overall handling is also affected.
When towing, allow for extra time when switching lanes, stopping and passing
other vehicles. To assist in slowing down, many people use an electric
trailer brake controller. The extra length can cause problems on
turns. Because the trailer does not follow the exact path as the vehicle
on turns, remember to swing out wider when traveling around bends and
corners. To conserve fuel when towing, travel at moderate speeds.
Faster speeds increase wind resistance, reduce gas mileage, and place added
strain on the vehicle and trailer. When traveling over large hills or
down gravel roads, use a lower gear to ease transmission and engine
operation. Shifting out of overdrive and into a lower gear may also
improve vehicle gas mileage.
If for some
reason (a gust of wind, a downgrade, a pass by a larger vehicle, etc.) the
trailer does begin to sway, the driver needs to assess the situation to
determine the proper course of action. Here is a list of Do's and Don'ts
to think about.
Also, be extra
cautious of potholes and other large bumps. Riding over one can damage
the tow vehicle, trailer
hitch and/or
trailer. When pulling a trailer take your time and be careful.
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DO |
DON'T |
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Gradually Reduce Speed Steady the Steering Wheel - Sudden Turns
can Worsen Sway Apply only the trailer brakes (if
applicable) |
Do Not Slam on the Brakes - Jackknifing
Could Occur Do Not Attempt to Steer Out of a Sway
Situation Do Not Increase Speed - Sway Increases
in Faster Speeds Do Not Tow a Trailer that Continues to
Sway |
Trailer
Hitches, Receivers and Ballmounts - Keep in mind the trailer's gross trailer weight and tongue
weight when selecting trailer hitches and ballmounts. Hitches or
Receivers are specific to each vehicle and are rated accordingly. To find
out how much your vehicle can tow, see the owner's manual. Class III
Ballmounts are selected not only with gross trailer weight in mind, but also
trailer height. The more level the trailer, the easier it is to
pull. Class I and Class II Ballmounts are specific for each vehicle and
are recommended by the hitch manufacturer.
Trailer Wiring - ALWAYS make sure the turn signals,
brake lights, taillights, electric brakes, and breakaway switches are working
on the trailer prior to each use. If the trailer has some wiring
problems, refer to this basic wiring diagram for the proper wiring. Be sure to find a
good secure ground on the trailer and also on the tow vehicle. If the
vehicle still needs to be wired, most auto stores carry harness for trailer
hitch wiring applications.
Trailer
Couplers - The inside of
the coupler should be clean and slightly lubricated.
Safety Chains -
ALWAYS connect the trailer's safety chains to the trailer hitch or tow vehicle
by crossing them underneath the coupler. Safety chains should only be
long enough to allow for tight turns. Anything longer may weaken the
safety feature of the chains if the other connections fail. Make sure the
chains cannot wiggle or bounce free and do not let them drag on the ground.
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Hitch Balls - Always make sure the
ball's weight rating is greater than the gross trailer weight rating. As for
the hole diameter, it must be less than 1/16" greater than the ball
shank diameter. When tightening, always use the lock washer and make
sure a portion of the ball shank extends past the bottom the nut. |
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Sway Controls - Available in two
different styles, sway controls reduce the effects of wind gusts and sudden
maneuvering by applying resistance to the trailer and vehicle with respect to
each other. Aside for trailers with a large surface area, such as
enclosed or travel trailers, sway controls are also used on trailers with a low
tongue weight percentage.
Weight Distribution - Weight Distribution
Systems are usually recommended for vehicles towing more than 5,000 lbs.
The systems improve braking and handling while increasing the towing capacity
of some trailer hitches.
Trailer Tires - Check tire inflation and
tread wear often. Fill the tires to match manufacturer's guidelines, for
tires with too much or too little air pressure can cause the trailer to
sway.
Trailer Towing Mirrors - Available in a
custom or universal fit, towing mirrors increase visibility by allowing the
driver to see the end of the trailer. This makes backing up and passing
other vehicles much easier.
Electric Trailer Brake Controls - For use
with trailers that have electric brakes, electric brake controllers send the
signal that applies the trailer's brakes.
Transmission Coolers - A must for all
towing vehicles with automatic transmissions. Transmission coolers lower
the operating temperature of the oil by up to 60 degrees. Every 20 degree
drop in temperature can double both oil and equipment life by reducing deposits
and stress on the seals. Overheating causes 90% of transmission failures.
