Removal & Installation
- Remove the air cleaner upper cover, housing, and clean air tube.
- Raise the vehicle on hoist.
- Remove the accessory drive belts.
- Remove the crankshaft vibration damper.
- Remove the air conditioner/generator belt tensioner and pulley assembly.
- Remove the timing belt lower front cover bolts and remove cover.
- Lower the vehicle.
Remove the bolts attaching timing belt upper front cover and remove cover.
NOTEWhen aligning the crankshaft and camshaft timing marks always rotate engine by the crankshaft. Camshaft should not be rotated after the timing belt is removed. Damage to the valve components may occur. Always align the timing marks before removing the timing belt.
Before removal of the timing belt, rotate the crankshaft until the TDC mark on the oil pump housing aligns with the TDC mark on the crankshaft sprocket (trailing edge of the sprocket tooth).
NOTEThe crankshaft sprocket TDC mark is located on the trailing edge of the sprocket tooth. Failure to align the trailing edge of sprocket tooth to TDC mark on oil pump housing will cause the camshaft timing marks to be misaligned.
- Install 6 mm Allen wrench into belt tensioner. Before rotating the tensioner, insert the long end of a 1 / 8 inch 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 inch or 3 mm Allen wrench, until it slides into the locking hole.
- Remove timing belt.
Remove crankshaft sprocket using Special Tools 6793 and insert C-4685-C2, or equivalent.
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.
- Install crankshaft sprocket using Special Tool 6792, or equivalent.
Set crankshaft sprocket to TDC by aligning the sprocket with the arrow on the oil pump housing.
Set camshafts timing marks so that the exhaust camshaft sprocket is a
notch below the intake camshaft sprocket.
CAUTIONEnsure that the arrows on both camshaft sprockets are facing up.
Install timing belt. Starting at the crankshaft, go around the water pump sprocket, idler pulley, camshaft sprockets and then around the tensioner.
Move the exhaust camshaft sprocket counterclockwise to align marks and take up belt slack.
- 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 22 ft. lbs. (30 Nm). Setting notch and spring tang should remain aligned after lock nut is torqued.
Remove Allen wrench and torque wrench.
NOTERepositioning 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.
- 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.
- 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.
- Install timing belt front covers and bolts.
- Install air conditioning/generator belt tensioner and pulley.
- Install crankshaft vibration damper.
- Install accessory drive belts.
- Install drive belt splash shield.
- Install air cleaner housing, upper cover, and clean air tube.
Before servicing the vehicle, refer to the Precautions section.
WARNINGBefore removing the timing belt, the engine must be placed at 90° after TDC. Failure to do so may result in valve and/or piston damage during assembly.
- Disconnect negative battery cable.
- Remove engine cover.
- Remove cooling fan and fan drive viscous clutch assembly.
- Remove accessory drive belt.
- Remove cooling fan support.
- Remove vibration damper.
- Bring piston No. 1 to TDC, turn crankshaft until the witness line on the crankshaft hub is at the 12 o-clock position.
- Looking at the engine from the belt side, rotate the crankshaft 90° clockwise so the witness mark is now at the 3 o-clock position.
- Remove the alternator.
- Remove the intake and exhaust camshaft plugs from the camshaft cover, to introduce the camshaft timing pins VM.1052 Intake, and VM.1053 Exhaust (if the engine is timed correctly, the pins can be installed flush with the intake manifold/cylinder head cover).
- Remove timing belt outer cover.
- Loosen timing belt tensioner and remove timing belt.
- Remove the intake and exhaust camshaft alignment pins.
- Loosen camshaft gears using special tool VM 1085 to retain the gears when loosening the bolts.
Remove special tool VM 1085.
There are marks on both camshaft gears. These ARE NOT alignment marks and should be disregarded.
- With both camshaft alignment pins still installed and the engine rotated at 90° after TDC, verify that the camshaft gears are loose.
Align the timing mark on the high pressure injection pump gear with the timing mark on the inner cover.
NOTEDO NOT remove the timing belt from the package until it-s ready to be installed. DO NOT expose timing belt to oil, grease or water contamination. DO NOT crimp belt at a sharp angle. DO NOT clean belt, pulleys or tensioner with solvent. Check that pulleys and bearings are not seized or damage before installing belt.
- Install timing belt on crankshaft hub.
- Route the belt around high pressure injection pump, idler pulley, intake camshaft gear, exhaust camshaft gear, idler pulley, and water pump gear.
- Adjust the timing belt tensioner (turn it clockwise) using special tool VM.9660, lining up the center notch with the aluminum cover dowel pin. Tighten the retaining bolt to 20 ft. lbs. (28 Nm).
- Install special tool VM.1085 between camshaft gears and tighten thumb screws to engage and retain the camshaft gears.
- Tighten the camshaft gear bolts to 80 ft. lbs. (108 Nm) while holding the gears with special tool VM 1085.
- Remove camshaft gear locking tool.
Remove intake and exhaust alignment pins.
WARNINGIf intake manifold/cylinder head cover was removed wait 30 minutes before rotating crankshaft.
- Rotate the engine clockwise 2 revolutions (looking at engine from the belt side).
- With the crankshaft hub witness mark aligned to 90 ° ATDC, or the 3 o-clock position, check that the intake and exhaust camshaft alignment pins (VM 1052 and VM 1053) can be installed into the camshaft alignment access holes.
Install timing belt outer cover.
WARNINGIf the camshaft alignment pins can not be installed at this time, repeat the procedure from the beginning.
- Install the camshaft access plugs.
- Install vibration damper.
- Install the alternator.
- Install cooling fan support.
- Install accessory drive belt.
- Install cooling fan and fan drive viscous clutch assembly.
- Install engine cover.
- Connect negative battery cable.