33. Timing Chain and Sprocket Clean and Inspect

Timing Chain and Sprockets Cleaning and Inspection
1. Inspect the timing chain guides for cracking or wear.





2. Replace the timing chain guides if wear exceeds 1.0 mm (0.039 inch) (1).





3. Inspect the timing chain for elongation wear.
4. Use a Vernier caliper and measure the length of 16 links with the timing chain fully stretched (1).
Maximum Chain Elongation 122.6 mm (4.827 inch)

Important: Make the measurements at three or more places of the timing chain at random.

5. If the elongation is greater than maximum, replace the timing chain.
6. Inspect the camshaft and sprocket faces for signs of movement.
7. Inspect the camshaft and crankshaft sprocket teeth and chain for signs of chipping or seizure of the timing chain links.





8. Inspect the timing chain and timing sprockets for wear.
9. Wrap the timing chain around each sprocket.
10. Use a Vernier caliper to measure the timing sprocket diameter with the chain.

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

^ Minimum Camshaft Sprocket Diameter With Chain Camshaft Sprocket: 97.3 mm (3.831 inch)
^ Minimum Crankshaft Sprocket Diameter With Chain Crankshaft Sprocket: 51.6 mm (2.031 inch)
11. If the diameter of any of the sprockets measured is less than the minimum, replace the timing chain and sprockets.





Notice: Refer to Fastener Notice in Service Precautions.

12. Install the CMP actuator to the intake camshaft.
^ Tighten the CMP actuator bolt to 54 Nm (40 ft. lbs.).
13. Ensure that the CMP actuator will not turn.
14. Apply air pressure of approximately 100 kPa (14 psi) to the advance passage of the camshaft.
15. Turn the CMP actuator to the advanced angle side by hand.
16. Rotate the actuator back and forth through the advanced positions to ensure 21 degrees of movement.
17. Remove the air pressure and turn the CMP actuator back to the minimum advanced angle position to lock it.
18. Replace the CMP actuator if the following conditions exist:
^ CMP actuator does not lock with air pressure removed.
^ CMP actuator does not unlock with air pressure applied.
^ CMP actuator does not rotate smoothly through the advanced positions.
^ CMP actuator does not rotate completely through the advance positions.