Chevrolet 2009 Express Owner's Manual page 225

Dinghy Towing Two-Wheel-Drive Vehicles
Notice: If the vehicle is towed with all four wheels
on the ground, the drivetrain components could
be damaged. The repairs would not be covered by
the vehicle warranty. Do not tow the vehicle with all
four wheels on the ground.
Two-wheel-drive vehicles should not be towed
with all four wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed.
All-Wheel-Drive Vehicles
The vehicle was not designed to be towed with all four
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
with any of its wheels on the ground.
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