Timing Belt: Service and Repair
TIMING BELT AND SPROCKETSREMOVAL
TIMING BELT
1. Disconnect negative battery cable.
2. Remove upper and lower front timing belt covers (Fig. 161).
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.
3. 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) (Fig. 166).
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.
4. Loosen timing belt tensioner lock bolt (Fig. 167).
5. Insert a 6 mm Allen wrench into the hexagon opening located on the top plate of the belt tensioner pulley (Fig. 167). Rotate the top plate CLOCKWISE until there is enough slack in timing belt to allow for removal.
6. Remove timing belt.
CAUTION: If timing belt was damaged due to incorrect tracking (alignment), the belt tensioner pulley and bracket must be replaced as an assembly.
CAMSHAFT SPROCKET(S)
1. Remove upper and lower front timing belt covers.
2. Remove timing belt.
3. Use Special Tool 6847 to hold camshaft sprockets while removing the sprocket bolt(s) (Fig. 168). Remove camshaft sprocket(s).
CRANKSHAFT SPROCKET
1. Remove upper and lower front timing belt covers.
2. Remove timing belt.
3. Remove crankshaft sprocket using Special Tool 6793 and insert C-4685-C2 (Fig. 169).
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.
1. Install crankshaft sprocket using Special Tool 6792 (Fig. 170).
2. Install timing belt.
3. Install upper and lower front timing belt covers.
CAMSHAFT SPROCKET(S)
CAUTION: Do not use an impact wrench to tighten camshaft sprocket bolts. Damage to the camshaft-to-sprocket locating dowel pin may occur.
1. Install camshaft sprockets. Hold sprockets with Special Tool 6847 while tightening center bolt to 115 Nm (85 ft. lbs.) (Fig. 168).
2. Install timing belt.
3. Install upper and lower front timing belt covers.
TIMING BELT
1. Set crankshaft sprocket to TDC by aligning the sprocket with the arrow on the oil pump housing.
2. Set camshafts timing marks so that the exhaust camshaft sprocket is a 1/2 notch below the intake camshaft sprocket (Fig. 171).
CAUTION: Ensure that the arrows on both camshaft sprockets are facing up.
3. Install timing belt. Starting at the crankshaft, go around the water pump sprocket, idler pulley camshaft sprockets and then around the tensioner (Fig. 172).
4. Move the exhaust camshaft sprocket counterclockwise (Fig. 172) to align marks and take up belt slack.
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 (Fig. 173). Using the allen wrench to prevent the top plate from moving, torque the tensioner lock bolt to 25 Nm (220 inch lbs.). Setting notch and spring tang should remain aligned after lock bolt 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.
7. 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. 174).
8. Check if the spring tang is within the tolerance window (Fig. 175). 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 upper and lower front timing belt covers (Fig. 161).
10. Connect negative cable to battery.