How to replace Mercedes Serpentine Belt Tensioner

How to replace Mercedes-Benz Tensioner

Last Updated on Thursday Jul 19, 2018

Step-by-step directions on how to replace Mercedes-Benz serpentine belt tensioner. Replacing the belt tensioner on Mercedes-Benz engine is relatively easy. It requires a few basic tools and approximately 30 minutes. This guide applies to the majority of Mercedes-Benz cars. The procedure is the same for many engines including M112, M113, M273. 

The average price to change the belt tensioner at the dealer ranges between $400-$650. Local repair shops will charge between $280-$450. The DIY cost to change Mercedes-Benz drive belt tensioner ranges between $50-$120, even if you have to buy the tools needed for this job and a new serpentine belt. 

VIDEO: How to change Mercedes tensioner

The following video shows you how to replace Mercedes-Benz drive belt tensioner. This video was recorded with the front end of the car removed for demonstration purposes. It is not necessary to remove the radiator or cooling fan to replace Mercedes tensioner.

If your Mercedes engine has a turbo, parts of the turbo will need to be removed to access the tensioner. 

What you will need

Parts Needed

Tools Needed

Optional

While it is not required to replace the drive belt, it makes sense to replace it at the same time as the tensioner. It is ok to use the old belt if it does not show wear, cracking, degradation or drying out. 

Instructions

  1. Park your Mercedes-Benz, set the parking brakes and allow the engine to cool down. 
  2. Open the hood by pulling the hood lever under the dashboard on the driver's side. 
  3. Use a 17mm socket to move the tensioner up (service) position.change mercedes tensioneer 
  4. Insert a metal pin in the tensioner hole to keep the tensioner up.loosen mercedes drive belt. A 5mm Allen wrench or bolt can be used as a pin. The pin needs to be strong enough to withhold shear force. Do not use any item made of plastic as a pin. mercedes tensioner service position pin

     

  5. Slide the drive v poly belt away from the tensioner. remove belt from tenisoner mercedes benz e c s ml

     

  6. Remove the top torx bolt using an E12 Trox socket and a 2" extension. diy tensioner mercedes

     

  7. Remove the lower torx bolt. lower bolt tensioner mb

     

  8. Some models also have a shock attached to the tensioner. Remove the upper bolt from the shock to disconnect it from the engine block. mercedes tensioner removed from engine

     

  9. Install the new timing belt tensioner. Start threading the tensioner bolts by hand until a few threads have gone in. 
  10. Torque the tensioner bolts to the recommended manufacturer specifications. Typical torque for the tensioner bolts ranges between 25Nm to 35 Nm. Check with your dealer. 
  11. Install the drive belt. Make sure it is routed on all the pulleys properly. If the belt does not reach, make sure it is not sitting on top of one of the pulleys. installed mercedes drive belt tensioner

     

  12. Put pressure on the tensioner 17mm head to move the tensioner up and remove the locking pin. 
  13. Start the engine and ensure the belt and tensioner are working properly. 

Over time the tensioner pulley can start to crack. If not replaced on time, it can fail while the engine is running. Drive belt will come off the various pulleys possibly causing damage.  The tensioner pulley bearing may also fail. When this happens you would normally hear noise coming from the front of the engine. 

PART NUMBER FITTMENT

1122000970

Interchange Part Numbers
  • 112 200 09 70
  • 0002020019
  • 5096525AA,
  • 68020888AA,
  • A0002020919,
  • 38174 49262 89335
  • 1122000070,
  • 1122000170,
  • 1122000370,
  • 1122000870,
  • 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

2722000270

(272 200 02 70)

  • 06 - 07 MERCEDES-BENZ C230 2.5L 2496CC V6 DOHC
  • 06 - 06 MERCEDES-BENZ C280 3.0L 2996CC 183CU. IN. V6
  • 06 - 07 MERCEDES-BENZ C280 3.0L 2996CC 183CU. IN. V6 DOHC
  • 06 - 07 MERCEDES-BENZ C280 3.0L 2996CC V6 DOHC
  • 10 - 11 MERCEDES-BENZ C300 3.0L 2996CC 183CU. IN. V6 DOHC
  • 08 - 12 MERCEDES-BENZ C300 3.0L 2996CC V6 DOHC
  • 10 - 11 MERCEDES-BENZ C300 3.5L 3498CC 213CU. IN. V6 DOHC
  • 06 - 09 MERCEDES-BENZ C350 3.5L 3498CC 213CU. IN. V6 DOHC
  • 06 - 11 MERCEDES-BENZ C350 3.5L 3498CC V6 DOHC
  • 07 - 10 MERCEDES-BENZ CL550 5.5L 5461CC V8 DOHC
  • 06 - 09 MERCEDES-BENZ CLK350 3.5L 3498CC 213CU. IN. V6 DOHC
  • 06 - 09 MERCEDES-BENZ CLK350 3.5L 3498CC V6 DOHC
  • 07 - 09 MERCEDES-BENZ CLK550 5.5L 5461CC V8 DOHC
  • 06 - 10 MERCEDES-BENZ E350 3.5L 3498CC 213CU. IN. V6 DOHC
  • 06 - 10 MERCEDES-BENZ E350 3.5L 3498CC V6 DOHC
  • 07 - 12 MERCEDES-BENZ GL450 4.6L 4663CC V8 DOHC
  • 07 - 09 MERCEDES-BENZ GL450 4.7L 4663CC 285CU. IN. V8 DOHC
  • 08 - 12 MERCEDES-BENZ GL550 5.5L 5461CC V8 DOHC
  • 10 - 12 MERCEDES-BENZ GLK350 3.5L 3498CC V6 DOHC
  • 10 - 11 MERCEDES-BENZ ML350 3.0L 2987CC V6 DIESEL DOHC TURBOCHARGED
  • 07 - 11 MERCEDES-BENZ ML350 3.5L 3498CC 213CU. IN. V6 DOHC
  • 07 - 11 MERCEDES-BENZ ML350 3.5L 3498CC V6 DOHC
  • 10 - 11 MERCEDES-BENZ ML350 5.5L 5461CC 333CU. IN. V8 DOHC
  • 08 - 11 MERCEDES-BENZ ML550 5.5L 5461CC V8 DOHC
  • 07 - 11 MERCEDES-BENZ S550 5.5L 5461CC V8 DOHC
  • 07 - 08 MERCEDES-BENZ SL550 5.5L 5461CC V8 DOHC
  • 06 - 08 MERCEDES-BENZ SLK280 3.0L 2996CC V6 DOHC
  • 09 - 11 MERCEDES-BENZ SLK300 3.0L 2996CC V6 DOHC
  • 05 - 09 MERCEDES-BENZ SLK350 3.5L 3498CC 213CU. IN. V6 DOHC
  • 05 - 11 MERCEDES-BENZ SLK350 3.5L 3498CC V6 DOHC
2712000270
  •  03-05 Mercedes-Benz C230 Kompressor 1.8L