Timing Belt Technical Information

Noise

  1. Tension too high: belt howls, whistles
  2. Tension too low: belt hits the drive guard

Solution

    1 and 2 Set the correct tension

Teeth and fabric have become detached from the carcase

  1. Leakage from the engine or the engine accessories (e.g. leakage of oil, anti-freeze etc.)

Solution

  1. Stop leakage, change belt

Defective system components

  1. Bearing play
  2. Damaged running surfaces

Solution

    1 and 2 Change the guide idler, tension roller and/or the guide roller

Wear of the pulley teeth/base cracks and stripped teeth

  1. Tension too high/low
  2. Foreign body ingress
  3. Jammed timing belt or idler(s)

Solution

  1. Remove the foreign body
  2. Check that the drive guard sits correctly
  3. Determine cause (e.g. defective bearing) and recitify, change belt

Edge wear

  1. Pulley/idler shafts are not parallel; belt runs against pulley flanges
  2. Pulleys/idlers are out of line:belt runs against pulley flanges
  3. Flanged pulley has a defective flange
  4. Pulley/idler bearings have too much play

Solution

  1. 1. and 2. Check drive; align pulleys that are not in line and if necessary replace; change belt
  2. 3. and 4. Replace components where necessary

Tooth damage

  1. Foreign body inside timing belt
  2. Timing belt pulley tooth defect caused by foreign object or tools during installation
  3. Timing belt damaged prior to or during installation

Solution

  1. Remove the foreign body,change belt, check that the drive guard is fitted correctly
  2. Replace damaged timing belt pulleys, change belt and install correctly
  3. Change belt and fit correctly

Top surface tears

  1. Ambient temperature too high/low
  2. Influence of contaminant
  3. Back idler bearing worn or falling
  4. Ageing

Solution

  1. Determine cause (e.g. check engine cooling) and rectify, change belt
  2. Change belt, check that the guard is fitted correctly
  3. Renew idler, change belt
  4. Change belt

Timing belt brekage

  1. Foreign object in drive
  2. Influence of contamination
  3. Pre-tension too high
  4. Belt crimping prior to or during installation

Solution

  1. Remove foreign object/media, change belt
  2. Change belt, check that the guard is fitted correctly
  3. Change belt, set the correct tension
  4. Change belt and fit correctly

Wear of the tooth facing fabric

  1. Tension set too high
  2. Worn timing belt pulley

Solution

  1. Change belt, set the correct tension
  2. Replace timing belt pulley, change belt