How do you fix the noise in the rear end on an 04 ford explorer?

To fix noise in the rear end of a 2004 Ford Explorer, start by inspecting the differential fluid level and condition; low or dirty fluid can cause noise. Check for worn or damaged components, such as the rear axle bearings, bushings, and driveshaft U-joints. If the noise persists, consider having the rear differential inspected by a professional to diagnose potential issues like gear wear or failure. Regular maintenance, including fluid changes, can help prevent future noise problems.