Damper pulley fitting instructions from NTN-SNR

The damper pulley has an essential role to play, as it drives all of the engine accessories. Here NTN-SNR offers advice on changing the damper pulley.

NTN-SNR-copy-1Why change the damper pulley?

Simplicity and cost reduction:

After changing the engine timing parts, you should change the damper pulley, this is to reduce the vehicles down time and maintenance costs.

Damper pulley deterioration may lead to a power steering malfunction.


Deterioration in damper pulley causes noise and vibrations and can lead to the seizure of the air conditioning pump, malfunction of power steering and alternator damage. All of this gives the driver a bad driving experience and high vehicle maintenance costs.

The pulley environment:
Other elements in the pulleys working environment can cause damage and deterioration to the pulley such as oil or coolant leak these can damage the damper pulley rubber joints.

When certain symptoms appear, it is necessary to check the damper’s condition:
Unusual vibrations inside the cabin.
Whistling coming from the timing belt.
An unusual noise or knocking connected to the engine.

NTN-SNR-copy-2Advice for disassembly

  • Never use screwdrivers, extractors or other methods that put pressure on the metal ring of the pulley.
  • Never use heat to disassemble the pulley unit, this can lead to damage to the rubber components and distort the metal components of the pulley.
  • The use of appropriate tools is required. We recommend the HAZET kit Ref. 1789 N-1, for removing the pulley correctly.

Advice for assembly

  • Avoid shocks to the face of the pulley where in contact with the timing sprocket, the contact points of screws, joints and timing belt (risk of lack of tightening, leaks, belt wear).
  • Do not exceed the maximum torque recommended for the screws (risk of cracking or deformation). Use of a torque wrench is required.
  • Never start the engine without the accessories belt connected.
  • Avoid all contact with oil, solvents, fuel, acid and anti freeze (risk of rubber deterioration).

Any new parts that show signs of damage from possibly being dropped knocked together etc should not be fitted to the vehicle. To avoid the risk of oxidation, it is recommended that parts be handled with clean, dry gloves.

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Published on: February 24, 2015

Filled Under: Technical Articles

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