how to fix the rear differential noise on my Volvo XC90

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Use jack stands to elevate the rear of the vehicle safely.

2. Drain Differential Fluid

• Place a drain pan under the differential.
• Remove the drain plug using a socket wrench and allow the fluid to fully drain.
• Inspect the fluid for metal shavings or debris, which indicates internal wear.

3. Remove Differential Cover

• Remove the bolts securing the differential cover using a socket set.
• Carefully pry the cover off to avoid damaging the gasket.
• Clean the mating surfaces of the cover and differential housing thoroughly.

4. Inspect Internal Components

• Visually inspect the gears, bearings, and ring and pinion for wear or damage.
• Rotate the differential by hand to check for any roughness or binding.
• Replace any worn or damaged components such as bearings or gears as necessary.

5. Reassemble Differential

• Install a new gasket or apply gasket maker on the differential cover.
• Reattach the differential cover and torque the bolts to the manufacturer's specifications (typically around 20-30 ft-lbs).
• Refill the differential with the appropriate fluid type (usually 75W-90 gear oil) until it reaches the fill level.

6. Test Drive

• Lower the vehicle and perform a test drive to ensure the noise has been resolved.
• Monitor for any signs of leaks or abnormal sounds.