Trailer Jack
Model 37792
Assembly and Operating Instructions
®
3491 Mission Oaks Blvd., Camarillo, CA 93011
Copyright 1998 by Harbor Freight Tools®. All rights reserved. No portion of this manual
or any artwork contained herein may be reproduced in any shape or form without the
express written consent of Harbor Freight Tools.
For technical questions and replacement parts, please call 1-800-444-3353.
Thank you for choosing a Harbor Freight Tools product! For future reference please com-
plete the owner’s record below:
Model:_______________
Purchase Date:_________________
SAVE THE RECEIPT, WARRANTYAND THESE INSTRUCTIONS. IT IS IMPORTANT THAT
YOU READ THE ENTIRE MANUAL TO BECOME FAMILIAR WITH THIS PRODUCT BEFORE YOU BEGIN ASSEMBLY.
______________________________________________________________________________
Specifications
Purpose: Jack mounts to side of straight trailer tongue. Once connected to the trailer, the Trailer Jack
makes hitching, unhitching, leveling, and moving the trailer a simple and safe procedure. TheTrailer
Jack can be used on heavy farm duty trailers as well as recreational boat trailers.
The Trailer Jack is designed for permanent or semi-permanent attachment to the trailer tongue, and can
be available for use wherever the trailer goes.
MinimumHeight:
MaximumHeight:
LiftingRange:
Capacity:
8”
22 1/2”
14 1/2”
550 lbs. load (not including load supported by trailer wheels)
Designed with a heavy duty worm gear drive with built-in gear box. Includes a grease fitting for easy
lubrication.
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Unpacking
Carefully unpack theTrailer Jack and check all parts against the parts diagram and part number listing
on pages 6. Do not discard any packing material until the Trailer Jack is fully assembled and opera-
tional. If any parts are missing or broken, please call Harbor Freight Tools at 1-800-444-3353
Assembly
TheTrailer Jack requires some minor assembly. Please follow the steps outlined below:
1. Place the Caster Wheel (#5) into the Caster Bracket (#4). Insert the Axle Bolt (#9), and tighten
with the Locking Nut (#10).
2. Install the wheel assembly shaft into the lower end of the Jack Shaft (#1). Screw in the Bolt (#12),
making sure that the Bolt sets in the grove of the wheel assembly shaft.
3. Place the Crank Handle (#3) on the shaft of the Jack Shaft, and align the flat surface to the handle.
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Assembly (continued)
Screw on the Locking Nut (#11) and tighten the nut securely.
4. Plan the location of the Trailer Jack. Examine both sides of the trailer tongue and choose the appro-
priate location for the jack, keeping in mind the mounting method, and the need to turn the Crank
Handle. The Trailer Jack is designed to be mounted on either side of the trailer tongue, and pivot in
either direction (caster wheel forward or to the rear).
5. Before installing theTrailer Jack, properly support the tongue of the trailer so that it is high enough
off the ground to provide clearance for the jack. Take precautions to insure the trailer is blocked and
will not roll.
6. Position the Trailer TongueAssembly portion of the Trailer Jack on top of the tongue. Position the
loose plate of the Trailer TongueAssembly underneath the tongue. Insert bolts through the top plate
and through to the bottom plate. Note the hole selections on the loose plate. Use the hole positions
which will best support your trailer tongue design. Install lock washers and nuts. At this time tighten
nuts only enough to hold theTrailer Jack in position for adjustment.
7. Inspect the position of the Trailer Jack. Check the squrareness of the mount position, and tap lightly
into alignment with a hammer and a wood block if necessary. Bolts should be at right angles to the
mounting plates. There should be proper clearance of the trailer tongue from the Jack Shaft. Once
determined that theTrailer Jack is properly positioned, tighten the nuts evenly, increasing pressure by
small increments on alternate bolts so that the mounting plates remain parallel. Nuts should be more
than tight enough to fully compress the washers, but not tight enough to damage the threads. Turn the
Crank Handle both ways to make sure the Trailer Jack is functioning properly.
8. Before operating the Trailer Jack, lubricate the grease fitting on the side of the Trailer TongueAs-
sembly. Use a good quality gear grease. Lubricate periodically while the Trailer Jack is in use.
Read and understand carefully the warnings and cautions described below as they pertain to
the operation of the Trailer Jack:
are securely attached, and that all bolts and nuts
1. Be aware that the user/installer of this prod-
are tight and in good condition.
uct is solely responsible for the way theTrailer
5. Always keep feet, arms, and legs out from
Jack is installed, operated and maintained, and is
under the trailer tongue while hitching, unhitch-
responsible for any and all consequences that
ing, or moving the trailer. Children should be
occur, whether or not anticipated in these
kept at a safe distance, and should never be
warning statements.
allowed to operate the Trailer Jack.
2. Never exceed the rated load capacity of 550
lbs. for the jack.
6. Always take precautions to prevent uncon-
trolled movement of the trailer when theTrailer
3. Never loosen, adjust, or take apart the top
Jack is being used. Be cautious of the slope of
and bottom plates of the TrailerTongueAssem-
the road and be aware of the pull of gravity
bly while theTrailer Jack is supporting any
when using this product.
weight.
4. Before each use, verify that the plates of the
TrailerTongueAssembly and the trailer tongue
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Operation
Unhitching:
To use theTrailer Jack as an aid in unhitching the trailer, first make sure that the Trialer Jack is securely
attached to the trailer tongue. Check out bolt/nut connection to make sure the TrailerTongueAssembly
is properly connected to the trailer tongue.
Take the neccessary precautions against uncontrolled trailer movement, and loosen the trailer hitching
mechanism. Attach the Crank Handle, if it has been detached in prior use, and turn the handle clock-
wise to increase the length of the Trailer Jack until the tongue has been lifted from the hitch ball. Keep
all body parts clear of the hitch, the tongue, and the area underneath the tongue.
Hitching:
To use theTrailer Jack as an aid in hitching the trailer, maneuver the trailer so that the trailer’s hitch is
directly over the towing vehicle’s hitch ball. Turn the Crank Handle counterclockwise to shorten the
Trailer Jack, and lower the tongue hitch onto the hitch ball. Tighten the hitch retainer mechanism.
Continue turning the Crank Handle until theTrailer Jack is fully retracted.
It is recommended that the Crank Handle be detached in preparation for towing. Keep all body parts
clear of the hitch, the tongue, and the area underneath.
Leveling and Moving:
In the unhitched mode, the trailer can be leveled or adjusted in pitch angle by turning the Crank Handle
in either clockwise or counterclockwise direction to lengthen or shorten the Trailer Jack. In this mode,
the trailer is a three wheeled vehicle that can be moved from one position to another, but only with
suitable precautions against uncontrolled movement. If the trailer is to be stored in this mode, it is
advised that the Crank Handle be detached and that the trailer wheels be properly blocked.
Towing:
When theTrailer Jack is attached while the trailer is being towed, theTrailer Jack must be fully retracted
(before towing begins, turn the Crank Handle counterclockwise until theTrailer Jack is fully retracted).
The Crank Handle needs to be removed and stored in a safe place while the trailer is being towed.
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Part Number Listing and Parts Diagram
Grease Fitting
Part #
Description
Jack Shaft
TrailerTongueAssembly
Crank Handle
Caster Bracket
Caster Wheel
Bolt M10 x 120
Nylon Locking Nut M10
Washer
Quantity
1
2
3
4
5
6
7
8
1
1
1
1
1
4
4
4
1
1
1
1
9
Bolt M12 x 80
10
11
12
Nylon Locking Nut M12
Nylon Locking Nut M12
Bolt M6 x 20
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