1997 GMC Sonoma Owner's Manual - Page 209

Rear Towing Tow Limits -- 35 mph (56 k d h ) , 50 miles (80 km) NOTICE: Do not tow with sling-type equipmentor rear bumper valance damagewill occur. Use wheel-lift or car-carrier equipment. Additional ramping may be required for carrier equipment.Use car safety chains and wheel straps. Towing a vehicle over rough surfaces could damage a vehicle. Damage can occur from vehicle to ground or vehicle to wheel-lift equipment. To help avoid damage, install a towing dolly and raise the vehicle until adequate clearance is obtained between the ground and/or wheel-lift equipment. Do not attach winch cables or J-hooks to suspension components when using car-carrier equipment. Always use T-hooksinserted in the T-hookslots. Vehicles with four-wheel-drive with electronic transfer case option must a towing dolly under the front use wheels when towingfrom the rem 5-11