Timing Chain: Inspection

Inspect timing chain and timing sprockets .
1. Using vernier calipers, measure the length of the 16 links with the chain fully stretched.
  1. 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.
  
  Fig 2: Measuring Timing Sprocket
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using vernier calipers, measure the timing sprocket diameter with the chain.
NOTE: Vernier calipers must contact the chain rollers for measuring.

Minimum sprocket diameter (w/ Chain):

Fig 3: Displaying Camshaft Specifications
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the diameter is less than minimum, replace the chain and sprockets.
Inspect chain tensioner slipper and vibration damper .

Fig 4: Measuring Tension Slipper & Vibration Damper Wear
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the chain tensioner slipper and vibration damper wears.
1. Maximum wear: 1.0 mm (0.039 in.)
If the wear is greater than maximum, replace the slipper and/or damper.
Inspect chain tensioner .
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.
Inspect drive belt tensioner .
Check the oil leakage and crack.

If necessary, replace the drive belt tensioner.