Jeep 2007 Liberty - Manual (Page 286)

Trailer Hitch Classification
The rear bumper is intended to tow trailers up to 2,000
lbs (907 kg) without added equipment or alterations to
the standard equipment. Your vehicle may be factory
equipped for safe towing of trailers weighing over 2,000
lbs (907 kg) with the optional Trailer Tow Prep Package.
See your dealer for package content.
The following chart provides the industry standard for
the maximum trailer weight a given trailer hitch class can
tow and should be used to assist you in selecting the
correct trailer hitch for your intended towing condition.
Refer to the Trailer Towing Weights (Maximum Trailer
Weight Ratings) chart for the Max. GTW towable for your
given drivetrain.
Improper Adjustment of Weight Distributing System
286 STARTING AND OPERATING