Timing Chain: Inspection

1. Using vernier calipers, measure the length of the 16 links with the chain fully stretched.
   Fig 1: Measuring 16 Links Length Using Vernier Calipers

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Maximum chain elongation: 122.6 mm (4.827 in.) 

   If the elongation is greater than maximum, replace the chain.

   NOTE: Make the same pulling measurements at 3 or more places selected at random.
2. Wrap the chain around the timing sprocket.
3. Using vernier calipers, measure the timing sprocket diameter with the chain.
Fig 2: Measuring Timing Sprocket Diameter Using Vernier Calipers
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the diameter is less than minimum, replace the chain and sprockets.

Measure the chain tensioner slipper and vibration damper wears.

Fig 3: Measuring Chain Tensioner Slipper & Vibration Damper Wear

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Maximum wear: 1.0 mm (0.039 in.) 

If the wear is greater than maximum, replace the slipper and/or damper.

1. Check that the plunger moves smoothly when the ratchet pawl is raised with your finger.
2. Release the ratchet pawl and check that the plunger is locked in place by the ratchet pawl and does not move when pushed with your finger.

Fig 4: Releasing Ratchet Pawl & Inspecting Plunger Locked Position

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the oil leakage and crack.

If necessary, replace the drive belt tensioner.