Here's a general procedure. Specific steps might vary slightly depending on your exact rear axle configuration (e.g., limited slip differential). Always consult your owner's manual for the specific recommendations for your truck.
Tools You'll Need:
* Vehicle jack and jack stands: Essential for safety. Never work under a vehicle supported only by a jack.
* Wheel chocks: To prevent the vehicle from rolling.
* Wrench(es): The size depends on your axle's drain and fill plugs. You'll likely need a socket wrench and possibly a breaker bar for stubborn plugs. Check your owner's manual or look under the truck to determine the sizes.
* Drain pan: To catch the old lubricant. A large capacity is recommended.
* Funnel: To add new lubricant.
* Torque wrench: Crucial to tighten the drain and fill plugs to the manufacturer's specified torque. Incorrect tightening can damage the axle. Consult your owner's manual for the proper torque specification.
* Gloves: To protect your hands.
* New rear axle lubricant: The correct type and amount are crucial. Your owner's manual specifies the type (e.g., 75W-90, 75W-140) and the capacity. Buy a bit extra to account for spillage.
* Shop rags or paper towels: For cleanup.
Procedure:
1. Preparation: Park on a level surface, engage the parking brake, and chock the front wheels. Consult your owner's manual to locate the drain and fill plugs on your specific axle.
2. Jacking and Securing: Safely jack up the rear of the truck and securely support it with jack stands.
3. Locate Drain and Fill Plugs: The drain plug is typically located at the bottom of the differential housing. The fill plug is usually higher up on the same housing. They are often square or hex-shaped.
4. Drain the Old Lubricant: Place the drain pan under the drain plug. Carefully remove the drain plug using the appropriate wrench. Let the old lubricant drain completely. This may take some time.
5. Inspect the Old Lubricant: Check the lubricant for metal particles or other debris. This can indicate a problem within the differential.
6. Replace Drain Plug: Once drained, reinstall the drain plug and tighten it to the manufacturer's specified torque using your torque wrench. Do not overtighten.
7. Locate Fill Plug: The fill plug is usually higher on the differential housing.
8. Add New Lubricant: Using a funnel, carefully add the correct amount of new lubricant specified in your owner's manual. It's often helpful to slightly overfill and then check the level using the fill plug hole. The lubricant should come out of the fill hole when the axle is full.
9. Replace Fill Plug: Once the correct amount of lubricant is added, install and tighten the fill plug to the manufacturer's specified torque using your torque wrench. Do not overtighten.
10. Lower Vehicle: Carefully lower the vehicle using the jack.
11. Check for Leaks: Inspect the area around the drain and fill plugs for any leaks.
12. Disposal: Dispose of the old lubricant properly at a designated recycling center or auto parts store.
Important Considerations:
* Limited-Slip Differential: If your truck has a limited-slip differential, you'll need to use the correct type of lubricant designed for limited-slip differentials. This is often a friction modifier additive added to the regular gear oil. Consult your owner's manual.
* Torque Specifications: Following the correct torque specifications is absolutely critical to prevent damage to the axle.
This is a general guide. Always refer to your owner's manual for specific instructions and torque specifications for your 2004 Dodge Ram 1500. If you are not comfortable performing this task, seek the assistance of a qualified mechanic. Incorrectly performed, this procedure can lead to axle damage.
