1998 GMC Sonoma Owner's Manual - Page 235

I NOTICE: Never removeor store a tire frondto a storage position under the vehicle while the vehicle is supported by a jack. Always tighten the tire fully against the undersideof the vehicle when storing it. Insert the chisel end of the wheel wrench, on an angle, intothe hole in the rear bumper. This is the jack cover for the extended cab. Thecover for the regular cab is similar. To remove it, turn the plastic wing nut to the left. Remove the jack cover. Turn the wing nut to the left and remove the wheel blocks, jack and wheel wrench. Your spare tire is stored underneath the rear of your vehicle. See. "Compact Spare Tire" later in this section for more information about the compact spare. Be sure the chisel end of the wheel wrench connects into the hoist shaft. 5-23