DIY Guide: Replacing Mercedes W220 Flex Discs, Intermediate Bearing, and Centering Sleeves

Mercedes-Benz W220 series, known for its luxury and advanced engineering, incorporates a two-piece propeller shaft to effectively transfer power from the engine to the rear axle. This system relies on several key components, including rubber flex discs, an intermediate bearing, and centering sleeves, to ensure smooth and reliable operation. While often overlooked, these parts are crucial for maintaining the vehicle’s driveline integrity and comfort. Many W220 maintenance discussions focus primarily on flex disc replacement, often assuming other related components are durable enough to last. However, experience suggests that the intermediate bearing and centering sleeves are also subject to wear and tear, potentially requiring replacement to maintain optimal performance.

Just like rubber engine and transmission mounts, the rubber components in the propeller shaft system degrade over time. Factors such as deteriorated engine and transmission mounts can exacerbate stress on these parts, leading to premature wear. Therefore, a comprehensive approach to propeller shaft maintenance is essential for W220 owners. As recommended by experienced Mercedes technicians, when undertaking flex disc replacement, it’s prudent to consider replacing the intermediate bearing, carrier, and dust boot simultaneously. This proactive approach can save time and labor costs in the long run, preventing future issues and ensuring long-term reliability.

The Mercedes W220 propeller shaft connects to the transmission and rear axle via rubber flex discs designed to absorb the intense torque generated by the engine and minimize driveline shock. The shaft itself consists of front and rear sections joined by a sliding connection, supported by an intermediate bearing encased in a rubber bushing and metal carrier. Centering rods in both the differential and transmission engage with centering bushings or sleeves at the propeller shaft ends, typically featuring a bronze bush within a rubber and outer sleeve assembly.

Several wear points can develop within this system:

• Flex Disc Cracking: Rubber flex discs are prone to cracking over time. This is a primary cause of driveline vibrations and noises and can lead to significant damage if left unaddressed.
• Intermediate Bearing Grease Degradation: The sealed intermediate bearing’s grease can break down, leading to squealing or seizing. Excessive play can also induce vibrations. Replacing the intermediate bearing and carrier has resolved driveline vibration issues reported by some owners, highlighting the importance of this component. A functional intermediate bearing should spin freely and quietly.
• Bearing Bushing Deterioration: The rubber bushing supporting the intermediate bearing has a limited lifespan. As the rubber ages, it can dry out, crack, and lose its ability to properly support the bearing.
• Dust Boot Degradation: The rubber boot sealing the splined connection between the propeller shaft sections can deteriorate, leading to grease leakage.
• Centering Sleeve Wear: Centering sleeves can wear at their sealing lips. The rubber hardens and shrinks, increasing the internal diameter of the seal and causing grease leaks. Interestingly, Mercedes-Benz W124 documentation suggests that worn centering sleeves can also contribute to vibrations, particularly during deceleration, emphasizing the importance of their condition and proper lubrication.
• U-Joint Wear: The sealed U-joint, like other sealed components, can eventually dry out and require replacement.

Vibrations originating from the driveline, especially noticeable in the rear console area, can be a significant source of discomfort and indicate underlying issues within the propeller shaft system.

Examining Propeller Shaft Wear on a Mercedes S500 (W220)

While my S500 didn’t exhibit noticeable driveline vibrations initially, a routine inspection prompted by dealer recommendations about the flex discs revealed several wear issues throughout the propeller shaft.

• Severe Flex Disc Cracking: The front flex disc displayed significant cracking, with a small piece broken off, surprisingly without causing noticeable vibrations. This highlighted the potential for sudden failure and the importance of proactive inspection. The concealed front side of the disc made visual inspection challenging without removal.

  Alt text: Severely cracked front flex disc of a Mercedes W220 S500, with a broken piece indicating advanced wear and potential failure.

• Intermediate Bearing Grease Degradation and Play: Visual inspection of the intermediate bearing showed dried grease deposits and noticeable play. While some play is expected due to the rubber bushing, excessive play in the bearing itself, combined with a soft grinding noise during rotation after removal, confirmed grease degradation.

  Alt text: Close-up of a Mercedes W220 intermediate bearing showing dried grease deposits, indicating potential wear and need for replacement.

• Rubber Boot Leakage: Deposits around the rubber boot at the spline connection suggested potential leakage, indicated by darker discoloration on the front propeller shaft.

  Alt text: Rubber dust boot on a Mercedes W220 propeller shaft with darker coloring indicating potential grease leakage and wear.

• Centering Sleeve Grease Leak and Wear: Although the centering sleeves appeared intact, all grease had leaked out. Measurement revealed a 1mm increase in the internal diameter of the old sleeve’s rubber sealing lip compared to a new one. This, along with the hardened rubber feel, indicated wear and likely leakage due to age-related shrinkage.

  Alt text: Worn Mercedes W220 centering sleeve with no grease visible and increased internal diameter due to rubber shrinkage, indicating wear and potential leakage.

  Alt text: New Mercedes W220 centering sleeve for comparison, showing intact rubber seal and proper dimensions, contrasting with the worn sleeve.

• U-Joint Condition: The U-joint appeared to be in good condition during this inspection.

Aim, Disclaimer, and Acknowledgements

This guide is intended for DIY enthusiasts with some mechanical experience who prefer a consolidated resource for performing this maintenance task. It is based on my personal experience as a novice DIYer and is not a substitute for official Mercedes-Benz workshop manuals. While I’ve strived for accuracy, I am not a professional technician, and this document reflects my first attempt at propeller shaft refurbishment.

The information provided is for informational purposes only. I cannot be held responsible for any outcomes resulting from the use of this guide. Users are responsible for ensuring their safety and the correct application of these procedures to their vehicles. Always consult official workshop manuals and take necessary safety precautions.

My approach to DIY projects involves thorough research and compilation of information from various sources into a single, practical guide for personal use. Sharing this experience is intended to assist fellow Mercedes-Benz owners. I welcome feedback and corrections from more experienced individuals to improve this resource.

I acknowledge the invaluable contributions of Mercedes-Benz Workshop Instructions Sheets (WIS), Pelican Parts technical articles, and insights from W220 forum members, including Check Codes, Ricebubbles, and Quadcammer, whose collective knowledge significantly aided this project.

Parts and Fluids Required

The following parts were used for my 2001 Mercedes-Benz S500 (W220):

• Flex Disc Kit (230 410 01 15): Includes two flex discs (front and rear) and new mounting hardware (T60 bolts, 18mm nuts, and washers). OEM flex discs are manufactured by Lemförder. Note: Lemförder kits (17979 01) may include one slightly shorter T60 bolt, the reason for which is unclear, but it’s included in the kit. During installation, the side with markings on the discs faced the rear of the vehicle in my case.

  Alt text: Mercedes W220 flex disc kit by Lemforder, including two discs and mounting hardware like bolts, nuts, and washers, essential for propeller shaft maintenance.

• Intermediate Bearing (008 981 43 25 or *** 6006RSR)

• Driveshaft Center Support/Carrier (211-410-01-81)

• Rubber Dust Boot (202 411 04 97)

• Centering Bushing/Sleeve (124-410-07-32)

  Alt text: Collection of Mercedes W220 propeller shaft components including flex discs, intermediate bearing, center support, dust boot, and centering bushing for a comprehensive replacement project.

Mercedes-Benz WIS recommends the following lubricants:

• Long-life grease (NLGI grade 2) MB 266.2 (A 000 989 63 51): For the splined profile at the sliding connection. This grease contains Castrol Olistamoly 2.

  Alt text: Mercedes-Benz MB 266.2 long-life grease, containing Castrol Olistamoly 2, recommended for lubricating the splined connection of the W220 propeller shaft.

• Multipurpose Grease (NLGI Class 2): For centering sleeve cavities (approx. 6 grams per sleeve). Mercedes-Benz Sheet 267.0 lists compatible greases, including Castrol LM Mehrzweckfett 2, Fuchs Renolit 283 EP 2, Mobilgrease MB 2, Shell Gadus S2 V145KP, and Total MULTIS 2. Castrol LM Grease is shown below.

  Alt text: Castrol LM Multipurpose Grease, a recommended NLGI Class 2 grease for lubricating the centering sleeves of a Mercedes W220 propeller shaft during maintenance.

Part 1: Exhaust System Removal

1. Vehicle Preparation: Safely lift the vehicle using jack stands, a lift, or ramps (front ramps, rear stands). Ensure rear wheels are free to rotate.
2. Exhaust Flange Disconnection: Locate the exhaust flange connections (typically three: 11/3, 11/4, and 11/5).
   • Remove the four bolts connecting the front and rear exhaust sections. Note: Nuts are 12mm (11/3), bolts are 13mm (11/5). Penetrating oil may be necessary for rusted bolts, and in severe cases, bolts may need to be cut.
   • Unscrew the two bolts (11/9) from the rear exhaust rubber mount (9/2). Support the rear exhaust assembly with jack stands or a helper.
   • With support for the rear exhaust assembly (either helper or jack stand), unscrew bolts (11/6) with nuts (11/7) from the front exhaust rubber mount (9/1).
   • Carefully lower and remove the rear exhaust section from under the vehicle. Remember to retrieve the exhaust sealing ring from the left side pipe joint.
   • Caution: Depending on vehicle lift height, support the front exhaust section ends to prevent strain on manifold bolts.

Part 2: Removal of Reinforcement Bridge and Shielding Plates

3. Rear Reinforcement Bridge Removal: Locate the rear reinforcement bridge (crossbar 35) near the rear end. Remove the four 13mm bolts securing it and remove the crossbar.

4. Front Exhaust Shielding Plate (105k) Detachment: Detach the front exhaust shielding plate (105k) from the exhaust shielding plate above the center muffler (105e).

   • Remove two 7mm nuts (one per side).
   • Remove three 8mm screws.
   • Slide the panel out, wiggling if necessary.

5. Exhaust Shielding Plate Above Center Muffler (105e) Detachment: In the tunnel area, remove two more 7mm nuts securing the exhaust shielding plate above the center muffler (105e).

6. Front Crossbrace (34) Removal: Locate the front crossbrace (34) near the transfer case. Remove the two 13mm bolts and the crossbrace. This step provides additional clearance for propeller shaft manipulation, particularly for flex disc removal.