1996 Ford Aerostar Owner's Manual - Page 275

Traction-Lok Rear Axle (If equipped) This axle provides added drive away traction on slippery surfaces, particularly when one or more wheels are on a surface with poor traction. RWARNING To avoid injury, never run the engine with one wheel off the ground, such as when changing a tire. Tire Rotation Because your vehicle's front and rear tires perform different jobs, they often wear differently. To make sure your tires wear evenly and last longer, rotate them at the mileage shown in the Maintenance Schedule and Record booklet which came with your vehicle. Rotate the tires according to the following diagram. If you notice that the tires wear unevenly, have them checked. If your light truck has a temporary spare tire, do not include it in the tire rotation pattern. In situations where the tires differ from front to rear (snow/traction), simply rotate using a side to side pattern. 297