Mercedes Serpentine Belt Replacement Guide
Updated Friday Jul 20, 2018
In this guide, you will find step-by-step instructions with pictures and video on how to change Mercedes-Benz serpentine belt. For instructions on how to change belt and tensioner, follow our guide on How to change Mercedes-Benz tensioner.
The instructions on how to change 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. Changing Mercedes-Benz serpentine is an easy task, and requires less than 30 minutes.
Symptoms that you need to change your Mercedes-Benz serpentine belt include squealing noise (most noticeable at startup). The serpentine belt may show signs of cracks, damages ribs. Other possible symptoms include powering steering noise, poor air conditioner, and even battery warning light. 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.Back to top
1. What you will need
ToolsBack to top
2. Mercedes Serpentine Belt Replacement Video
The following video shows you how easy it is to replace Mercedes-Benz serpentine belt.
This video was recorded with the radiator and fan removed for demonstration purposes. On most Mercedes models, it is NOT necessary to remove any parts to replace the belt.Back to top
3. Stey by Step Instructions
- Order the correct Mercedes-Benz serpentine belt for your car. The belt can be purchased online or at any auto parts store or dealer.
- Park the car and allow the engine to cool down.
- Open the hood by pulling the release under the dashboard on the driver's side.
- Locate the serpentine belt at the front of the engine.
- Place a 17mm socket and ratchet on the tensioner and move the tensioner UP. Turn the wrench counter-clockwise.Some models have a Hex bolt in the center of the pulley that can be used to release the drive belt. Do NOT use the secure TORX bolt to release the tensioner. Use the 17mm nut below the pulley.
- Insert a pin (such as a 6mm Allen wrench) into the locking hole. The tensioner needs to be all the way up to be able 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 is not inserted fully, it can snap off and cause damage or body injuries.
- Remove the old belt by sliding the belt away from all the pulleys.
- Install the new belt. Route it over the powering steering pump, A/C compressor, crankshaft, alternator, idler pulley. It is important that you take a picture of the old belt before you remove it, and use that as a reference.Otherwise, you will be wondering how to route the belt. On some cars, the serpentine belt routing is printed on top of the upper radiator support or under the hood.
- Next, slide the serpentine belt over the tensioner pulley.
- Check that the belt is seated properly on all the pulleys. If the belt is not seated properly even on one pulley it will be difficult to slide the belt over the tensioner.
- Use the 17mm to lift up the tensioner then remove the pin.
- Slowly lower the tensioner and allow it to load on the belt.
4. Important Notes
- No parts need to be removed to remove and replace Mercedes serpentine belt.
- Removing the engine cover by pulling it up, can make this job easier, but it is not necessary.
- Radiator cooling fan does not need to be removed.
- A pin can be used to 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 possibly last up to 100k miles. We recommend changing it every 60,000 miles.
5. Mercedes Serpentine Belt Replacement Cost
It costs less than $50 to change the Mercedes-Benz serpentine belt yourself. Average cost to change the belt at the dealer or mechanic ranges between $100 and $250 for labor and parts.Back to top
6. Mercedes Serpentine Belt Diagram
Typical routing of Mercedes Benz serpentine belt. Whenever possible take a picture or draw a sketch of the old belt routing before removal. The drive belt routing diagram may be printed underneath the hood or top of the radiator support.
Instructions on how to change 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