* Driving conditions: Heavy towing, off-road use, or frequent stop-and-go traffic will necessitate more frequent changes.
* Type of differential: The type of differential (limited-slip, standard) will influence the recommendation. Limited-slip differentials often require more frequent servicing.
* Ford's official recommendation: While you'll find various opinions online, the best source is your owner's manual. This manual will specify the recommended interval based on your specific vehicle's configuration and intended use.
General Guidelines (but consult your owner's manual!):
Many sources suggest a change every 30,000 to 60,000 miles for a standard differential under normal driving conditions. However, for heavier use or if you're unsure, getting it changed every 30,000 miles is a safer bet. Heavy-duty use might even warrant changes every 15,000-20,000 miles.
In short: Check your owner's manual first. It's the most reliable source for the correct maintenance schedule for your specific 2002 Ford E350 van. If you don't have the manual, you can often find a digital version online through Ford's website or a reputable automotive parts website.
