1997 Chevrolet Astro Owner's Manual - Page 226

A vehicle can fall from a car carrier it isn't if adequately secured.This can cause a collision, serious personalinjury and vehicle damage. The vehicle should be tightly secured with chains or steel cables before is transported. it Don't use substitutes (ropes, leather straps, canvas webbing, etc.) that can be cut by sharp edges underneath the towed vehicle. When your vehicle is being towed, have the ignition key in the OFF position. The steeringwheel should be clamped in a straight-ahead position, with a clamping device designed for towing service. Do not use the vehicle's steering column lock for this. The transmission should be in NEUTRAL (N) and the parking brake released. If your vehicle has the all-wheel-drive option, it can only be towed with all four wheels off the ground. A dolly must be used under the un-raised wheels when towing or the vehicle must be transported on a flat bed carrier. Don't have your vehicle towed with the wheels in contact with the ground if it has all-wheel drive. If a vehicle with all-wheel drive must be towed with sling-type or wheel-lift equipment, then either the front or rear wheels must be supported on a dolly. I NOTICE: If your vehicle has all-wheel drive, not haveit do towed with the wheels in contact with ground the or vehicle damage may occur. dolly must be A used under the un-raised wheels when towing or the vehicle must be transported on aflat bed carrier.