This process will be a broad overview. Consult a factory repair manual (like a Bentley or Haynes manual specific to your year and model E320) for detailed instructions, torque specifications, and diagrams. These manuals are essential for this type of repair.
Here's a general outline of the steps involved:
1. Safety First: Disconnect the negative battery terminal. Use jack stands securely to support the vehicle after lifting it. Wear safety glasses and gloves.
2. Preparation:
* Wheel Removal: Remove the wheel on the side of the axle being replaced.
* Brake Caliper Removal: Remove the brake caliper assembly and carefully support it to prevent damage to the brake line. Some methods involve hanging the caliper, others may use a wire or a specialized tool.
* Control Arm Removal (Possibly): Depending on the specific design and access, you may need to remove parts of the control arm assembly to gain sufficient clearance. This is where a repair manual is crucial.
* ABS Sensor (If Applicable): Carefully disconnect the ABS sensor if it's interfering with axle removal.
3. Axle Removal:
* Drive Shaft Removal: This is usually done at the differential end (rear) of the axle, not at the wheel end. You'll likely need a special drive shaft removal tool to separate the axle from the transmission or differential. This often involves breaking a retaining clip or a similar mechanism.
* Outer CV Joint Separation: The outer CV joint might need to be separated from the wheel hub. This usually involves removing a retaining clip or nut.
* Inner CV Joint Separation: The inner CV joint may need to be separated from the transmission or differential. This is often the most challenging part and might require specific tools.
4. Installation of the New Axle:
* Installation is the reverse of removal: Carefully align the new axle, ensuring the CV joints are properly seated and the drive shaft is correctly engaged.
* Tightening: Use the correct torque specifications from your repair manual for all bolts and nuts. Improper tightening can lead to premature wear and failure.
* Check for Leaks: Inspect for leaks after installation.
5. Reassembly:
* Reinstall all components: Carefully reinstall the brake caliper, wheel, etc., in the reverse order of removal.
* Torque Specificity: Use the proper torque values throughout the reassembly process, consult your service manual.
6. Testing:
* Test Drive: After completing the repair, perform a test drive to check for any unusual noises, vibrations, or handling issues.
Important Considerations:
* Specialized Tools: You'll need a variety of specialized tools, including a drive shaft removal tool, possibly a CV joint boot separator, torque wrenches, and potentially a wheel hub nut socket.
* CV Joint Boot: Consider replacing the CV joint boots during the repair, even if they don't appear damaged. Damaged boots allow grease to escape and contaminate the joint, causing premature failure.
* Professional Help: If you lack the experience or tools to perform this repair, it's highly recommended to take your vehicle to a qualified mechanic specializing in Mercedes-Benz vehicles. This is a complex repair with potential for significant damage if done incorrectly.
This is a simplified overview. Always consult a factory repair manual before attempting this repair. The specific steps and tools required may vary slightly depending on your specific vehicle and the type of drive axle installed. Improper repair can lead to serious damage or injury. Professional assistance is strongly advised.
