Timing Chain: Inspection

WARNING: This page is about a different car, the 2004 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT TIMING CHAIN AND TIMING SPROCKETS

Using vernier calipers, measure the length of the 16 links with the chain fully stretched.
Maximum chain elongation: 122.6 mm (4.827 in.)

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

HINT:

Make the same pulling measurements at 3 or more places selected at random.

Fig 1: Measuring Length Of Links
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Wrap the chain around the timing sprocket.

Using vernier calipers, measure the timing sprocket diameter with the chain.

Fig 2: Measuring Timing Sprocket Diameter With Chain

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NOTE: Vernier calipers must contact the chain rollers for measuring.

Minimum sprocket diameter (w/ Chain):

MINIMUM SPROCKET DIAMETER (W/CHAIN) SPECIFICATIONS

Camshaft	97.3 mm (3.831 in.)
Crankshaft	51.6 mm (2.031 in.)

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

INSPECT CHAIN TENSIONER SLIPPER AND VIBRATION DAMPER
Measure the chain tensioner slipper and vibration damper wears.

Maximum wear: 1.0 mm (0.039 in.)

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

Fig 3: Inspecting Chain Tensioner Slipper & Vibration Damper Wear
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT CHAIN TENSIONER
1. Check that the plunger moves smoothly when the ratchet pawl is raised with your finger.
  
  Fig 4: Checking Plunger Moves Smoothly
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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.