Timing Chain: Inspection

INSPECT NO. 1 CHAIN TENSIONER
1. Check that the plunger moves smoothly when the ratchet pawl is raised with your finger.
2. Release the ratchet pawl, then check that the plunger is locked in place by the ratchet pawl and does not move when pushed with your finger.
  
  Fig 1: Checking Plunger
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT CHAIN SUB-ASSEMBLY
1. 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 chain elongation is greater than the maximum, replace the chain sub-assembly.
  
  HINT:
  
  Take the same measurements by pulling at 3 or more places selected at random.
  
  Fig 2: Inspecting Chain Sub-Assembly
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT CHAIN TENSIONER SLIPPER
1. Using vernier calipers, measure the tensioner slipper wear.
  Maximum wear:
  
  1.0 mm (0.039 in.)
  
  If the wear is greater than the maximum, replace the chain tensioner slipper.
  
  Fig 3: Inspecting Chain Tensioner Slipper
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT NO. 1 CHAIN VIBRATION DAMPER
1. Using vernier calipers, measure the vibration damper wear.
  Maximum wear:
  
  1.0 mm (0.039 in.)
  
  If the wear is greater than the maximum, replace the No. 1 chain vibration damper.
  
  Fig 4: Measuring Vibration Damper Wear
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT CRANKSHAFT TIMING SPROCKET
1. Wrap the chain around the timing sprocket.
2. Using vernier calipers, measure the timing gear diameter with the chain.
  Minimum gear diameter (with chain):
  
  51.6 mm (2.031 in.)
  
  NOTE: Vernier calipers must be in contact with the chain rollers when measuring.
  
  If the gear diameter is less than the minimum, replace the chain sub-assembly and crankshaft timing sprocket.
  
  Fig 5: Measuring Timing Gear Diameter With Chain
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT OIL PUMP DRIVE GEAR
1. Wrap the chain around the drive gear.
2. Using vernier calipers, measure the drive gear diameter with the chain.
  Minimum gear diameter (with chain):
  
  48.2 mm (1.898 in.)
  
  NOTE: Vernier calipers must be in contact with the chain rollers when measuring.
  
  If the gear diameter is less than the minimum, replace the No. 2 chain sub-assembly and oil pump drive gear.
  
  Fig 6: Measuring Timing Gear Diameter With Chain
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT OIL PUMP DRIVE SHAFT GEAR
1. Wrap the chain around the drive shaft gear.
2. Using vernier calipers, measure the drive shaft gear diameter with the chain.
  Minimum gear diameter (with chain):
  
  48.2 mm (1.898 in.)
  
  NOTE: Vernier calipers must be in contact with the chain rollers when measuring.
  
  If the gear diameter is less than the minimum, replace the No. 2 chain sub-assembly and oil pump drive shaft gear.
  
  Fig 7: Measuring Drive Shaft Gear Diameter With Chain
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002