Mercedes-Benz Serpentine Belt Replacement Guide

This article will cover the steps for replacing the serpentine belt on a Mercedes-Benz vehicle. The serpentine belt, also known as the drive belt, is an essential component that powers various systems in the vehicle, such as the alternator, power steering pump, and air conditioning compressor.

Over time, the belt can become worn and may need to be replaced to ensure the proper functioning of these systems. Replacing the serpentine belt on a Mercedes-Benz vehicle can be a relatively simple task for the experienced DIY mechanic. Still, it’s important to understand the process well and the necessary tools before attempting so. We will provide a step-by-step guide on how to replace the serpentine belt on a Mercedes-Benz, as well as tips and tricks to make the process as smooth as possible.

Do you feel a squealing noise on your Mercedes-Benz, power steering noise, poor air conditioner, or warning lights coming on? These symptoms may be caused by a worn or broken serpentine drive belt.

Symptoms

Some common symptoms that the serpentine belt may need to be replaced include:

• Squealing or chirping noise coming from the front of the vehicle
• Visible cracks or fraying on the belt
• The belt appears loose or misaligned
• The vehicle failed to start.
• Loss of power steering or air conditioning

You must change your Mercedes-Benz serpentine belt if you notice symptoms such as squealing noise (most noticeable at startup). The serpentine belt may show signs of cracks and damaged ribs.  Other possible symptoms include powering steering noise, poor air conditioner, and battery warning lights. Do not ignore your serpentine belt if it shows signs of damage. If the belt comes off when the engine is running, it can cause unnecessary damage to engine components.

These instructions on changing the Mercedes serpentine belt (also known as Drive Belt, Poly V Belt) apply to all Mercedes-Benz cars with six and eight-cylinder gasoline engines such as M112, M13, M272, M273, etc. Replacing a Mercedes-Benz serpentine is an easy task and requires about thirty minutes.

What you will need

• Mercedes-Benz Serpentine Belt
• 17mm socket
• Ratchet wrench

Procedure

1. Order the correct Mercedes-Benz serpentine belt for your car. The belt can be purchased online or at any auto parts store or dealer.

2. Park the car and allow the engine to cool down.

3. Open the hood by pulling the release under the dashboard on the driver’s side.

4. Locate the serpentine belt at the front of the engine.

5. Place a 17mm socket and ratchet on the tensioner and move the tensioner UP. Turn the wrench counterclockwise. Some models have a Hex bolt in the pulley center that can release the drive belt. Do NOT use the secure TORX bolt to release the tensioner. Use the 17mm nut below the pulley.

6. Insert a pin (such as a 6mm Allen wrench) into the locking hole. The tensioner needs to be up to insert the locking pin. Make sure that the pin is strong enough and is inserted properly. If the pin is not inserted in the proper hole or fully inserted, it can snap off and cause damage or body injuries.

7. Remove the old belt by sliding the belt away from all the pulleys.

8. Install the new belt. Route it over the powering steering pump, A/C compressor, crankshaft, alternator, and idler pulley. It is important to take a picture of the old belt before removing it and using it as a reference. Otherwise, you will be wondering how to route the belt. The serpentine belt routing is printed on top of the upper radiator support or under the hood on some cars.

9. Next, slide the serpentine belt over the tensioner pulley.

10. Check that the belt is seated properly on all the pulleys. If the belt is not seated properly, it won’t be easy to slide over the tensioner, even on one pulley.

11. Use the 17mm to lift the tensioner and remove the pin.

12. Slowly lower the tensioner and allow it to load on the belt.

Notes

• No parts need to be removed to remove and replace the Mercedes serpentine belt.
• Removing the engine cover by pulling it up can make this job easier but unnecessary.
• The radiator cooling fan does not need to be removed.
• A pin can lock the tensioner in the UP (preloaded) position.
• It is possible to change the belt without using a locking pin.
• Take a picture of the belt routing before you remove the belt.
• Do not use the Secure Torx bolt to release the tensioner.
• If you have a turbo intake pipe, remove it to access the tensioner.
• The original belt can potentially last up to 100k miles. We recommend changing it every 60,000 miles.

Serpentine Belt Replacement Cost

It costs less than $50 to change the Mercedes-Benz serpentine belt yourself. The average cost to change the dealer or mechanic belt ranges between $200 and $450 for labor and parts.

Can I drive my Mercedes-Benz if the serpentine belt is broken?

It is not recommended to drive your car if the serpentine belt is broken, as it can cause several problems. A broken serpentine belt will cause the engine to shut off and prevent the alternator from charging the battery. The power steering and air conditioning will also stop working. This can create unsafe driving conditions and cause additional damage to your vehicle. It is best to have the belt inspected and replaced immediately.

Applications

Instructions on how to change the Mercedes-Benz drive belt apply to the following models. These instructions may apply to other models not included in this list.

• 2001 – 2005 C240
• 1998 – 2000 C280
• 2001 – 2005 C320
• 1998 – 2000 C43 AMG
• 2005 – 2006 C55 AMG
• 2000 – 2006 CL500
• 2001 – 2002 CL55 AMG
• 2003 – 2006 CL55 AMG
• 1998 – 2005 CLK320
• 1999 – 2003 CLK430
• 2003 – 2006 CLK500
• 2001 – 2006 CLK55 AMG
• 2006 CLS500
• 2006 CLS55 AMG
• 1998 – 2004 E320
• 2005 E320 4Matic
• 2005 E320 Base
• 1998 – 2002 E430
• 2003 – 2006 E500
• 1999 – 2002 E55 AMG
• 2003 – 2006 E55 AMG
• 2002 – 2008 G500
• 2005 – 2011 G55 AMG
• 1998 – 2003 ML320
• 2003 – 2005 ML350
• 1999 – 2001 ML430
• 2002 – 2007 ML500
• 2000 – 2003 ML55 AMG
• 2006 – 2007 R500
• 2006 S350
• 2000 – 2006 S430
• 2000 – 2006 S500
• 2001 – 2002 S55 AMG
• 2003 – 2006 S55 AMG
• 1999 – 2006 SL500
• 2003 – 2008 SL55 AMG
• 2001 – 2004 SLK320
• 2005 – 2010 SLK55 AMG
• 2007-08 Dodge Sprinter Van V6 3.5L
• 2006-09 Mercedes Benz C230
• 2010 Mercedes Benz C250
• 2006-07 Mercedes Benz C280
• 2008-13 Mercedes Benz C300
• 2006-11 Mercedes Benz C350
• 2010 Mercedes Benz CL550
• 2006-09 Mercedes Benz CLK350
• 2007-09 Mercedes Benz CLK550
• 2007-11 Mercedes Benz CLS550
• 2007 Mercedes Benz E280
• 2006-11 Mercedes Benz E350
• 2010 Mercedes Benz E500
• 2007-11 Mercedes Benz E550
• 2011-13 Mercedes Benz G550
• 2007-13 Mercedes Benz GL450
• 2010-13 Mercedes Benz GLK350
• 2006-11 Mercedes Benz ML350
• 2010-11 Mercedes Benz ML550
• 2006-11 Mercedes Benz R350
• 2007-11 Mercedes Benz S550
• 2007-13 Mercedes Benz SL550
• 2006-08 Mercedes Benz SLK280
• 2010-11 Mercedes Benz SLK300

We hope you find the “Mercedes-Benz Serpentine Belt Replacement Guide” helpful. Check these troubleshooting and repair guides for more help on your Mercedes-Benz.

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