Timing Belt: Service and Repair
TIMING BELT AND SPROCKET(S)REMOVAL - TIMING BELT
1. Remove air cleaner upper cover, housing, and clean air tube.
2. Raise vehicle on hoist.
3. Remove accessory drive belts.
4. Remove crankshaft vibration damper.
5. Remove air conditioner/generator belt tensioner and pulley assembly.
6. Remove timing belt lower front cover bolts and remove cover.
7. Lower vehicle.
8. Remove bolts attaching timing belt upper front cover and remove cover.
CAUTION: When aligning crankshaft and camshaft timing marks always rotate engine from crankshaft. Camshaft should not be rotated after timing belt is removed. Damage to valve components may occur. Always align timing marks before removing timing belt.
Fig. 98 Crankshaft And Camshaft Timing:
9. Before the removal of the timing belt, rotate crankshaft until the TDC mark on oil pump housing aligns with the TDC mark on crankshaft sprocket (trailing edge of sprocket tooth).
NOTE: The crankshaft sprocket TDC mark is located on the trailing edge of the sprocket tooth. Failure to align trailing edge of sprocket tooth to TDC mark on oil pump housing will cause the camshaft timing marks to be misaligned.
Fig. 99 Locking Timing Tensioner:
10. Install 6 mm Allen wrench into belt tensioner. Before rotating the tensioner, insert the long end of a 1/8" or 3 mm Allen wrench into the pin hole on the front of the tensioner. While rotating the tensioner counterclockwise, push in lightly on the 1/8" or 3 mm Allen wrench, until it slides into the locking hole.
11. Remove timing belt.
REMOVAL - CRANKSHAFT SPROCKET
1. Disconnect negative battery cable.
2. Remove timing belt.
Fig. 100 Crankshaft Sprocket Removal:
3. Remove crankshaft sprocket using Special Tools 6793 and insert C-4685-C2.
CLEANING
1. Do Not attempt to clean a timing belt. If contamination from oil, grease, or coolants have occurred, the timing belt should be replaced.
2. Clean all sprockets using a suitable solvent. Clean all sprocket grooves of any debris.
INSTALLATION - CRANKSHAFT SPROCKET
CAUTION: The crankshaft sprocket is set to a predetermined depth from the factory for correct timing belt tracking. If removed, use of Special Tool 6792 is required to set the sprocket to original installation depth. An incorrectly installed sprocket will result in timing belt and engine damage.
Fig. 101 Crankshaft Sprocket Installation:
1. Install crankshaft sprocket using Special Tool 6792 .
2. Install timing belt.
INSTALLATION - TIMING BELT
CAUTION: The crankshaft sprocket is set to a predetermined depth from the factory for correct timing belt tracking. If removed, use of Special Tool 6792 is required to set the sprocket to original installation depth. An incorrectly installed sprocket will result in timing belt and engine damage.
1. Set crankshaft sprocket to TDC by aligning the sprocket with the arrow on the oil pump housing.
Fig. 102 Camshaft Sprocket Alignment:
2. Set camshafts timing marks so that the exhaust camshaft sprocket is a 1/2 notch below the intake camshaft sprocket.
CAUTION: Ensure that the arrows on both camshaft sprockets are facing up.
Fig. 103 Timing Belt Installation - Typical:
3. Install timing belt. Starting at the crankshaft, go around the water pump sprocket, idler pulley, camshaft sprockets and then around the tensioner.
4. Move the exhaust camshaft sprocket counterclockwise to align marks and take up belt slack.
Fig. 104 Timing Belt Tension Adjustment:
5. Insert a 6 mm Allen wrench into the hexagon opening located on the top plate of the belt tensioner pulley Rotate the top plate COUNTERCLOCKWISE . The tensioner pulley will move against the belt and the tensioner setting notch will eventually start to move clockwise. Watching the movement of the setting notch, continue rotating the top plate counterclockwise until the setting notch is aligned with the spring tang. Using the allen wrench to prevent the top plate from moving, torque the tensioner lock nut to 30 Nm (22 ft. lbs.). Setting notch and spring tang should remain aligned after lock nut is torqued.
6. Remove allen wrench and torque wrench.
NOTE: Repositioning the crankshaft to the TDC position must be done only during the CLOCKWISE rotation movement. If TDC is missed, rotate a further two revolutions until TDC is achieved. DO NOT rotate crankshaft counterclockwise as this will make verification of proper tensioner setting impossible.
Fig. 105 Crankshaft And Camshaft Timing:
7. Once the timing belt has been installed and tensioner adjusted, rotate the crankshaft CLOCKWISE two complete revolutions manually for seating of the belt, until the crankshaft is repositioned at the TDC position. Verify that the camshaft and crankshaft timing marks are in proper position.
Fig. 106 Timing Belt Tension Verification:
8. Check if the spring tang is within the tolerance window. If the spring tang is within the tolerance window, the installation process is complete and nothing further is required. If the spring tang is not within the tolerance window, repeat Steps 5 through 7.
9. Install timing belt front covers and bolts.
10. Install air conditioning/generator belt tensioner and pulley
11. Install crankshaft vibration damper.
12. Install accessory drive belts.
13. Install drive belt splash shield.
14. Install air cleaner housing, upper cover, and clean air tube.