DIY Guide: Benz W220 Flex Discs, Intermediate Bearing, and Centering Sleeves Replacement

Maintaining the propeller shaft in your Benz W220 is crucial for a smooth and comfortable driving experience. While many discussions focus solely on replacing rubber flex discs, often overlooking other components, my experience with the W220 has highlighted the importance of addressing the intermediate bearing and centering sleeves as well. Especially if your benz w220 has endured wear and tear on engine and transmission mounts, these parts may be under more stress than initially anticipated.

Like all rubber and seal components, these parts on your benz w220 are subject to deterioration over time. As they age, rubber parts lose elasticity, and seals can harden and change shape, potentially leading to leaks and vibrations. Therefore, a comprehensive approach to propeller shaft maintenance is the best strategy.

I strongly agree with the recommendation from “Check Codes,” a respected member of the BW Elite community, who advises a complete replacement of the intermediate bearing, carrier, and rubber dust boot alongside the flex discs. His reasoning is sound: these components are unlikely to outlast two sets of flex discs. Opting for a complete overhaul now saves you from repeating the labor-intensive process later. For preventative maintenance on your benz w220, investing in both flex discs, the center bearing, carrier, and dust boot, and replacing them all at once is, in my opinion, the most efficient and effective approach.

The benz w220 Mercedes-Benz utilizes a two-piece propeller shaft system. This system connects the transmission to the rear axle via rubber flex discs designed to absorb the significant driveline shock produced by the engine’s torque. The propeller shaft consists of a front piece (10) and a rear piece (35), joined by a sliding connection that allows for telescoping or separation. This joint is supported by an intermediate bearing (50), housed within a rubber bushing and held by a metal carrier (45). Both the differential and transmission ends of the propeller shaft are fitted with centering rods that engage with centering bushings or sleeves (15 & 40). These centering sleeves appear to consist of a small bronze bush encased in rubber within an outer sleeve.

Several wear points can develop in the benz w220 propeller shaft system:

• Cracked Rubber Flex Discs: This is the most common issue and a frequent source of driveline vibration and noise in the benz w220. Failure of these discs can lead to significant damage.
• Intermediate Bearing Grease Degradation: Over time, the grease within the sealed intermediate bearing can break down. This can cause the bearing to squeal or seize if neglected, and excessive play in the bearing can also induce vibrations. Some benz w220 owners have reported that driveline vibrations disappeared after replacing the intermediate bearing and carrier. A functional intermediate bearing should spin freely and quietly. Binding, squeaking, or grinding indicates grease failure and the need for replacement.
• Deteriorated Bearing Bushing: The rubber bushing surrounding the intermediate bearing has a limited lifespan. As the rubber dries, cracks, and loses its elasticity, it can no longer adequately support the bearing.
• Damaged Rubber Dust Boot: The rubber boot sealing the splined connection between the two propeller shaft sections can degrade, leading to grease leakage.
• Worn Centering Sleeves: The sealing lips of the centering sleeves can wear down. The rubber can harden and shrink, increasing the internal diameter of the seal and causing leaks around the centering rods. Interestingly, a W124 WIS document mentions that worn centering sleeves can also be a source of vibrations, particularly during deceleration in manual transmission vehicles. It recommends checking the grease quantity and play in the centering sleeve, and replacing parts and replenishing grease as needed.
• U-Joint Wear: The U-joint is also sealed and subject to grease drying out over time, eventually requiring replacement.

These issues can manifest as vibrations transmitted into the cabin, often most noticeable in the rear console area of your benz w220, which can be quite bothersome.

Examining Propeller Shaft Wear on My Benz W220 S500

Initially, I wasn’t aware of any driveshaft vibrations in my benz w220 S500. However, after my Mercedes-Benz dealer recommended flex disc replacement, I decided to conduct a thorough inspection of all propeller shaft components.

• Front Flex Disc Condition: The front rubber flex disc on my benz w220 exhibited severe cracking. Alarmingly, a small section on the front side had already broken off – a critical issue hidden from a casual visual inspection due to transmission component obstruction. I was surprised that this hadn’t yet translated into noticeable vibrations, suggesting that failure was imminent.

Alt text: Severely cracked front flex disc of a Benz W220, highlighting rubber deterioration and potential failure point.

• Intermediate Bearing Inspection: Upon inspecting the intermediate bearing from underneath my benz w220, I observed dried grease deposits on the bearing exterior and noted some play. While some play is expected due to the rubber bushing, I detected play within the bearing itself. A subsequent turning and listening test after removal revealed a faint grinding noise, confirming grease degradation within the bearing, although it hadn’t yet reached the squealing stage.

• Carrier Bushing Condition: The rubber bushing of the carrier appeared to be in acceptable condition.

• Spline Connection Boot: Deposits around the rubber boot at the spline connection hinted at potential replacement needs, indicated by the darker discoloration visible on the right side of the hump in the front propeller shaft section in the image below.

Alt text: Close-up of the Benz W220 propeller shaft spline connection boot showing grease deposits indicating potential wear and need for replacement.

• Centering Sleeves Analysis: Although the centering sleeves initially seemed fine, I discovered a complete absence of grease. The WIS documentation specifies 6 grams of grease should be present. Measuring the internal diameter of the rubber sealing lip revealed a 1mm increase compared to a new centering sleeve. This diameter increase, along with the hardened feel of the old rubber compared to the replacement sleeves, led me to conclude that the leak resulted from the aging sealing lip and its increased internal diameter. The image below visually confirms this: the inner wall of the old centering sleeve bushing is more visible at a right angle than in the new sleeve.

Alt text: Comparison of old and new centering sleeves for Benz W220, illustrating grease leakage and wear on the old sleeve versus the pristine condition of the new replacement.

• U-Joint Condition: The U-joint appeared to be in good working order.

Aim, Disclaimer, and Acknowledgements

This guide is provided by a DIY enthusiast for fellow novice DIYers seeking a consolidated resource for performing this maintenance task on their benz w220. It is based on my personal experience as a novice undertaking my first propeller shaft refurbishment. This is not intended to replace official Workshop Instruction Sheets but rather to serve as a supplementary guide.

While the information presented here is believed to be reliable, I cannot be held responsible for outcomes resulting from its use, as workshop methods are beyond my control. Users are responsible for determining the suitability of these methods for their specific purposes and for implementing appropriate safety precautions. Always consult official Workshop Instruction Sheets and use this guide as a supplemental reference.

My approach to DIY projects involves thorough preliminary research, integrating information from various sources into a single, practical document for use during the task.

As a relatively inexperienced DIYer and not a native English speaker, I was initially hesitant to share my work. However, I welcome suggestions and corrections to improve this guide and hopefully make it a valuable resource for other benz w220 owners.

I acknowledge the invaluable contributions from official Workshop Instructions Sheets, Pelican Parts Technical articles, and forum members like Check Codes, Ricebubbles, and Quadcammer.

Parts and Fluids Required for Benz W220 Propeller Shaft Service

The image below shows the parts I used for my 2001 benz w220 S500:

Alt text: Essential replacement parts for Benz W220 propeller shaft maintenance, including flex discs, intermediate bearing, carrier, dust boot, and centering sleeves.

• Flex Disc Kit (230 410 01 15): Includes new mounting hardware (T60 bolts, 18mm nuts, and washers). OEM flex discs are manufactured by Lemförder. Two flex discs are required per vehicle (front and rear). Note: Lemförder kits (17979 01) include one slightly shorter T60 bolt – its purpose is unclear and hopefully doesn’t affect shaft balance. Installation note: writing on both discs faced the rear of my vehicle.
• Intermediate Bearing (008 981 43 25 or *** 6006RSR)
• Driveshaft Center Support or Carrier for the bearing (211-410-01-81)
• Rubber Dust Boot (202 411 04 97)
• Centering Bushing or Sleeve (124-410-07-32)

Recommended Fluids (WIS):

• Splined Profile Grease: Long-life grease (NLGI grade 2) for the sliding connection. MB 266.2 grease (A 000 989 63 51) contains Castrol Olistamoly 2 (pictured below).

Alt text: MB 266.2 long-life grease recommended for Benz W220 propeller shaft splined connections, featuring Castrol Olistamoly 2.

• Centering Sleeve Grease: 6 grams of Multipurpose Grease (Mercedes-Benz Sheet 267.0, NLGI Class 2) per sleeve. Examples include Castrol LM Mehrzweckfett 2, Fuchs Renolit 283 EP 2, Mobilgrease MB 2, Shell Gadus S2 V145KP, and Total MULTIS 2. Castrol LM Grease is pictured below.

Alt text: Castrol LM Multipurpose Grease, suitable for lubricating Benz W220 centering sleeves during propeller shaft maintenance.

Part 1: Exhaust System Rear Section Removal

1. Safely elevate your benz w220 using jack stands, a lift, or ramps (front on ramps, rear on stands). Rear wheels need to rotate freely.

2. Remove the exhaust system from the flange connection points (11/3, 11/4, and 11/5).

   2.1. To access the propeller shaft heat shield, the rear exhaust section needs removal. Begin by loosening and removing the four bolts connecting the front and rear exhaust sections. Note: nuts are 12mm (11/3), bolts are 13mm (11/5). Penetrating oil application may be necessary for heavily rusted bolts. Severely rusted bolts may require cutting.

   2.2. 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.

   2.3. With a helper supporting the rear exhaust assembly near the catalytic converters (or using a jack stand), unscrew bolts (11/6) with nuts (11/7) from the exhaust rubber mount (9/1).

   2.4. Carefully lower the rear exhaust system section from under the benz w220. Remember to retrieve the exhaust sealing ring from between the front and rear pipes on the left side.

   2.5. Caution: Depending on vehicle lift height, the front exhaust section ends may require support to prevent strain on manifold bolts.

Part 2: Reinforcement Bridge, Shielding Plates, and Crossbrace Removal

3. Remove the rear reinforcement bridge (crossbar 35). Locate the crossbar near the rear end, secured by four 13mm bolts. Remove these bolts and the crossbar.
4. Detach the front exhaust shielding plate (105k) from the exhaust shielding plate above the center muffler (105e). Remove the two 7mm nuts (one per side) and three 8mm screws. Slide the panel out, wiggling if necessary.
5. Detach the exhaust shielding plate above the center muffler (105e) in the tunnel area. Remove two additional 7mm nuts.
6. Detach the front crossbrace (34). Find the two 13mm bolts near the transfer case. Remove these bolts and the crossbrace. This provides additional clearance to maneuver the propeller shaft for flex disc removal.