Here's a step-by-step guide:
1. Gather Your Supplies:
* New rear differential gear oil: Use the correct type and weight specified in your owner's manual. This is usually a 75W-90 gear oil, but it could be different depending on your axle type (e.g., Dana 35, Chrysler 8.25). Get the right amount; the capacity is typically around 1.5 - 2 quarts, but check your manual.
* Drain pan: Large enough to hold at least 2 quarts of oil.
* Wrench(es): You'll need a socket wrench and the correct size socket for the drain plug and fill plug. These are usually 10mm or 13mm but could be different. A breaker bar might be necessary if the plugs are very tight.
* Torque wrench: Essential for tightening the drain and fill plugs to the correct specification. This prevents leaks and damage.
* Funnel: To help pour the new oil into the differential.
* Jack and jack stands: Crucial for safety. Never work under a vehicle supported only by a jack.
* Wheel chocks: Place these on the wheels opposite the side you are working on.
* Gloves: To protect your hands from the oil.
* Rags or paper towels: For cleaning up spills.
2. Prepare the Vehicle:
* Park on a level surface: Ensure the Jeep is securely parked on a level surface, engage the parking brake, and use wheel chocks.
* Locate the rear differential: It's located in the rear axle housing, usually near the center of the rear of the vehicle.
* Jack up the vehicle: Safely lift the rear of the Jeep using a jack, placing jack stands under the frame rails for secure support.
3. Drain the Old Oil:
* Locate the drain plug: It's usually on the bottom of the differential housing.
* Position the drain pan: Place the drain pan under the drain plug.
* Remove the drain plug: Carefully loosen and remove the drain plug using the appropriate wrench. The old oil will start to flow out. Be cautious, as it will be hot if the vehicle was recently driven.
* Allow the oil to drain completely: This may take 15-30 minutes.
4. Remove the Fill Plug (Optional but Recommended):
* Locate the fill plug: It's usually on the top or side of the differential housing.
* Remove the fill plug: Loosen and remove the fill plug with the appropriate wrench. This allows for better flow when refilling.
5. Reinstall the Drain Plug:
* Clean the drain plug: Wipe the drain plug clean to remove any debris.
* Install the drain plug: Carefully reinstall the drain plug and tighten it to the correct torque specification using your torque wrench. Do not overtighten.
6. Add New Gear Oil:
* Use a funnel: Pour the correct amount of new gear oil into the differential housing through the fill hole. Refer to your owner's manual for the exact capacity.
* Check the oil level: Once you've added the specified amount, the oil level should be at the bottom of the fill hole. If using the fill plug as a reference point, fill until the oil starts to come out.
7. Reinstall the Fill Plug:
* Clean the fill plug: Wipe the fill plug clean.
* Install the fill plug: Carefully reinstall the fill plug and tighten it to the correct torque specification using your torque wrench. Again, do not overtighten.
8. Lower the Vehicle:
* Carefully lower the vehicle: Slowly lower the Jeep using the jack.
9. Check for Leaks:
* Inspect for leaks: Check around the drain and fill plugs for any leaks. If you see any leaks, tighten the plugs slightly (using the torque wrench), but don't overtighten.
Important Notes:
* Safety First: Always prioritize safety. Use jack stands, chocks, and follow safe jacking procedures.
* Correct Oil: Use the correct type and weight of gear oil specified in your owner's manual. Using the wrong oil can damage your differential.
* Torque Specifications: The correct torque specifications are crucial. Overtightening can strip the threads, while undertightening can cause leaks. Consult your owner's manual.
* Disposal: Dispose of the used oil properly according to local regulations. Many auto parts stores accept used oil for recycling.
If you are uncomfortable performing this task yourself, take your Jeep to a qualified mechanic. It's better to be safe than sorry when working on your vehicle.
