1996 Ford Aerostar Owner's Manual - Page 182

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. Extended use of other than matching size tires on a Traction-Lok rear axle could result in a permanent reduction in effectiveness. This loss of effectiveness does not affect normal driving and should not be noticeable to the driver. High water Never attempt to cross water that is fast flowing or of unknown depth. Do not drive through flooded areas unless you are sure that the water is below the bottom of the wheel hubs. If you must drive through high water, drive slowly. You may have limited traction or wet brakes, so allow extra stopping distance because your vehicle will not stop as quickly as usual. After you drive through the standing water, apply your brakes gently several times as your vehicle moves slowly. This helps to dry the brakes. NOTE: If the transmission and transfer case is submerged in water, their fluids should be checked and changed, if necessary. NOTE: All rear axle lube quantities must be replaced every 100,000 miles (160,000 km) or if the axle has been submerged in water. Otherwise, the lube should not be checked or changed unless a leak is suspected or repair required. 201