GMC 2007 Savana - Manual (Page 266)

5. Release the parking brake only after the
vehicle being towed is firmly attached to
the tow vehicle.
6. Turn the ignition to LOCK.
If the tow vehicle will not be started or driven
for six weeks or more, remove the battery
cable from the negative terminal (post) of the
battery to prevent your battery from draining
while towing.
All-Wheel-Drive Vehicles
Your vehicle was not designed to be towed with
two wheels on the ground. To properly tow
these vehicles, they should be placed on a
platform trailer with all four wheels off the ground.
Notice: Towing an all-wheel-drive vehicle
with all four wheels on the ground, or even
with only two of its wheels on the ground, will
damage drivetrain components. Do not tow
an all-wheel-drive vehicle if any of its wheels
will be on the ground.
Towing a Trailer
{ CAUTION:
If you do not use the correct equipment
and drive properly, you can lose control
when you pull a trailer. For example, if the
trailer is too heavy, the brakes may not
work well — or even at all. You and your
passengers could be seriously injured.
Pull a trailer only if you have followed all
the steps in this section. Ask your dealer
for advice and information about towing a
trailer with your vehicle.
Notice: Pulling a trailer improperly can
damage your vehicle and result in costly
repairs that would not be covered by your
warranty. Always follow the instructions in this
section and check with your dealer for more
information about towing a trailer with
your vehicle.
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