Master Lock 2939AT Instructions D'installation page 3

TOWING EQUIPMENT
TRAILER HITCHES, RECEIVERS, AND BALL MOUNTS Select these products by taking into account their gross trailer weight and tongue weight ratings.
Match the products according to the anticipated use. Use only those products designed for your vehicle.
HITCH BALLS Select the proper hitch ball by gross trailer weight rating, mounting platform thickness, hole size, and coupler socket size. Do not
interchange one class of hitch ball with another class of coupler. Platform must be at least 3/8" thick. Mounting hole must not exceed threaded shank
diameter by more than 1/16". Use lock washer. Tighten per instructions, and when tightened, shank must extend beyond bottom of nut. Gross trailer
weight rating and ball diameter are marked on all hitch balls.
COUPLERS The coupler opening should be smooth, free of dirt, and lightly lubricated. Tighten or adjust per manufacturer's instructions. Use recommended class type.
SAFETY CHAINS AND CABLES Use safety chains or cables EVERY TIME YOU TOW. Chains or cables should cross under the coupler. This is done to form
a cradle for the trailer tongue in the event the ball and coupler separate. Install to the hitch or tow vehicle so they can't bounce loose. Leave only enough
slack to permit full turning of the vehicle. Having too much slack in the chains may prevent chains from maintaining control if other connections fail.
Chains or cables shouldn't drag on the road to avoid chain failure.
TRAILER LIGHTS, TURN SIGNALS, ELECTRIC BRAKES, AND BREAK AWAY SWITCH CONNECTIONS Connect these safety-critical items EVERY TIME YOU
TOW, no matter how short the trip. Check operations including electric brake manual control, before getting on the road.
SWAY CONTROLS Sway controls lessen the effects of sudden maneuvers, wind and buffeting from other vehicles. They're recommended for trailers with large
surface areas. Adjustable friction models can help control trailers with low tongue weight. Recommended tongue weight should be 10% of gross trailer weight.
OTHER EQUIPMENT AIR SPRINGS, AIR SHOCKS, or HELPER SPRINGS are used for some towing applications. A TRANSMISSION COOLER may be
necessary for heavy duty towing. Some states require TOWING MIRRORS on both sides of the vehicle.
TIRE INFLATION Check often. Follow tow vehicle and trailer manufacturers' recommendations. Improper tire inflation can cause uncontrollable trailer sway.
CHECK YOUR EQUIPMENT Check hitch ball, coupler, safety chains/cables, retaining pins and clips, and all other connectors EVERY TIME YOU TOW.
Check again at stops.
Contains Important Information About Towing
TOWING EQUIPMENT OWNERS: Make sure all users of your equipment read and understand the information below before using. Keep this
information for future reference. This information will help you properly select, use, and maintain your towing equipment. Refer to the owner's
manuals for your tow vehicle, trailer, and other parts of your towing system. Learn the capabilities and limitations of each component. GROSS
TRAILER WEIGHT and TONGUE WEIGHT are two of the most important items to consider. THESE WEIGHTS MUST NEVER EXCEED THE
LOWEST RATING OF ANY PART OF YOUR TOWING SYSTEM. GROSS TRAILER WEIGHT is the weight of the trailer plus all cargo. Measure
GROSS TRAILER WEIGHT by putting the fully loaded trailer on a vehicle scale (Fig. 1). TONGUE WEIGHT is the downward force exerted on the
ball by the trailer coupler. Measure TONGUE WEIGHT with the fully loaded trailer on a level surface. The coupler must be at its normal towing
height. Use a commercial scale as shown for heavy tongue weights (Fig. 2).
Fig. 1: HOW TO MEASURE GROSS TRAILER WEIGHT
PUT FULLY LOADED TRAILER ON VEHICLE SCALE
This product complies with regulation V-5, C.S.A. Standard D-264 and safety requirements for connecting devices and towing systems of the state of New York.
THREE YEAR LIMITED WARRANTY
Master Lock Company warrants this hitch against defects in material and workmanship under normal recreational use and service, ordinary wear and tear excepted, for three years from the
date of purchase of the original consumer purchaser. Master Lock Company will replace FREE OF CHARGE any part which proves defective in material or workmanship when returned to factory,
TRANSPORTATION CHARGES PREPAID, at the address below. THIS WARRANTY IS LIMITED TO DEFECTIVE PARTS REPLACEMENT ONLY. LABOR CHARGES AND/OR DAMAGE INCURRED IN
INSTALLATION OR REPLACEMENT AS WELL AS INCIDENTAL AND CONSEQUENTIAL DAMAGES CONNECTED THEREWITH ARE EXCLUDED. Some states do not allow the exclusion or limitation
of incidental or consequential damages, so the above limitation or exclusion may not apply to you. Any damage to the Hitch, Custom Hitch receiver or Sway Control as a result of misuse, abuse,
neglect, accident, improper installation, or any use violative of instructions furnished by us, WILL VOID THE WARRANTY. This warranty gives you specific legal rights, and you may also have
other rights which vary from state to state. In the event of a problem with warranty service or performance, you may be able to go to a small claims court, a state court, or a federal district court.
Master Lock Company warrants this product to be free of defects in material and workmanship at the time of retail purchase by the original purchaser.
If the product is found to be defective, Master Lock Company may repair or replace the product, at their option, when the product is returned, prepaid,
with proof of purchase. Alteration to, misuse of, or improper installation of this product voids the warranty. Master Lock Company's liability is limited
to repair or replacement of products found to be defective, and specifically excludes liability for incidental or consequential loss or damage.
Master Lock Company Return Goods
c/o All In One Warehouse
2050 N. Smokey Lane, Suite B
Nogales, AZ 85621
w w w . m a s t e r l o c k . c o m
Master Lock Company LLC, Milwaukee, WI 53154 U.S.A. | 800-308-9244
Master Lock Canada, Oakville, Ontario L6H 5S7 Canada | 800-227-9599
© 2008 Master Lock Company | All Rights Reserved
83175
Fig. 2: HOW TO MEASURE TONGUE WEIGHT
SET TONGUE OF FULLY LOADED TRAILER ON VEHICLE SCALE
Contact Customer Care at 1-800-308-9244 for return authorization.
05/08