1997 GMC Safari Owner's Manual - Page 226

I A vehicle can fall from acar carrierif it isn't adequately secured. This can cause a collision, serious personal injury andvehicle damage. The vehicle should be tightly secured with chains or steel cables before it is transported. Don't use substitutes (ropes, leather straps, canvas webbing, etc.) that can be cut by sharp edges underneath thetowed vehicle. When your vehicle is being towed, have the ignition key in the O W position. The steering wheel 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. NOTICE: If your vehicle has all-wheel drive, do not have it towed with the wheels in contact with the ground or vehicle damage may occur. A dolly must be used under the un-raised wheels when towingor the vehicle must be transported on a flat bed carrier. 5-8