2005 Chevrolet Express Van Owner's Manual - Page 226

If you'll be pulling a trailer that, when loaded, will weigh more than 5,000 lbs (2 270 kg), be sure to use a properly mounted weight-distributing hitch and sway control of the proper size. This equipment is very important for proper vehicle loading and good handling when you're driving. You should always use a sway control if your trailer will weigh more than these limits. You can ask a hitch dealer about sway controls. Will you have to make any holes in the body of your vehicle when you install a trailer hitch? If you're using the wiring provided with the factory-installed trailering package, you should not need to make any holes in the body of your vehicle. However, if you have an aftermarket hitch installed, you may need to make holes in the body. If you do, then be sure to seal the holes later when you remove the hitch. If you don't seal them, deadly carbon monoxide (CO) from your exhaust can get into your vehicle as well as dirt and water. See "Carbon Monoxide" under Engine Exhaust on page 2-27. Safety Chains You should always attach chains between your vehicle and your trailer. Cross the safety chains under the tongue of the trailer to help prevent the tongue from contacting the road if it becomes separated from the hitch. Instructions about safety chains may be provided by the hitch manufacturer or by the trailer manufacturer. Follow the manufacturer's recommendation for attaching safety chains and do not attach them to the bumper. Always leave just enough slack so you can turn with your rig. Never allow safety chains to drag on the ground. Trailer Brakes If your trailer weighs more than 1,000 lbs (450 kg) loaded, then it needs its own brakes - and they must be adequate. Be sure to read and follow the instructions for the trailer brakes so you'll be able to install, adjust and maintain them properly. Since your vehicle is equipped with StabiliTrak, your trailer brake system cannot tap into the vehicle's hydraulic brake system. 4-42