Timing Belts & Chains

We have a wide range of Timing belts & Timing Chain Kits. We stock Dayco belts & Ultra OEM chain kits. Please call 01455 250222 for more details.

Timing Belts & Kits

The timing belts keeps the engine in sync. After time the belt and it's components need to be replaced. Please check your service schedule to see when your replacement is due. The belt, rollers & tensioners should be checked periodically to ensure there is no damage or wear to the belt and that the rollers spin freely. If the cam belt fails the engine will have a catastrophic failure often resulting in bent or broken valves, snapped camshafts and damaged piston crowns. This is typical in an interference engine, which means the valve protude into the space where the piston reaches.

Trouble Chart - Timing belt automatic tensioner (Source: Dayco)

Metal contamination and oxidation

automatic tensioner: Metal contamination and oxidationCauses:

  • Contact with contaminating components: oil, dust, leakage of coolant

Actions:

  • remove leakage of coolant 
  • remove leakage of oil and/or fuel
  • replace the faulty/damaged component

 

Broken central pin

automatic tensioner: Broken central pinCauses:

  • Incorrect setting of the bolt: the torque applied is higher than the value specified on the maintenance sheet.

Actions:

  • apply the correct tightening torque
  • use the torque wrench
  • replace the faulty/damaged component

 

 

 

Broken Stop Contact

broken stop contact tensionerCauses:

  • Incorrect setting of the tensioner: "excessive unload" condition with the belt excessively slack in the transmission
  • Incorrect setting of the tensioner: "excessive load" condition with the belt tensioned in the transmission.

Actions:

  • replace the components when the engine is cold 
  • apply the correct tension to the belt
  • check the alignment of the reference indexes
  • check the belt tension after the adjustment turns
  • use the tensiometer to check the belt tension 
  • replace the faulty/damaged component

 

 

 

 

 

Broken stop contact / Dents on the end stop

tensioner lugs brokenCauses:

  • Incorrect setting of the tensioner with loss of capacity to modulate and compensate the belt tension variations

Actions:

  • replace the components when the engine is cold 
  • apply the correct tension to the belt
  • check the alignment of the tensioner reference indexes
  • check the belt tension after the adjustment turns
  • replace the faulty/damaged component

Timing Chain Kits

Chains generally have a longer service life than belts, but chains and their components need to checked regularly. Servicing is critical to the operation of the chain. Often, the chain tensioner works under oil pressure. If the oil is low or insufficient oil reaches the tensioner, the chain will run without enough tension which can damage guide rails and sprockets.