Service Intervals

On all models, check fluid level at 15,000-mile intervals. On 4R100 equipped models and under normal service, change fluid at 30,000-mile intervals. On 4R70W equipped models and under normal service, change fluid and filter at 150,000-mile intervals. See DRAINING & REFILLING . Service all models at 30,000-mile intervals when used under the following conditions:

• In hot weather with temperature greater than 90°F (32°C), carrying heavy loads and/or in hilly terrain.
• Towing a trailer or using a car top carrier.
• In police, taxi or door-to-door delivery service.
• Extreme dusty conditions or off-road use.