Timing Belt
TIMING BELTRemoval Steps 1-21:
REMOVAL AND INSTALLATION
Required Special Tools:
^ MB990767: End Yoke Holder
^ MD998715: Pins
^ MD998767: Tensioner Pulley Wrench
^ MD998769: Crankshaft Spacer
REMOVAL SERVICE POINTS
[A] TIMING BELT REMOVAL
CAUTION
Water or oil on the belt shortens its life drastically, so the removed timing belt, sprocket, and tensioner must be kept free from oil and water. These parts should not be washed or immersed in solvent. Replace parts if contaminated. If there is oil or water on any part, check the front case oil seal, camshaft oil seal, and water pump for leaks.
1. Mark the belt running direction for reinstallation.
2. Loosen the tensioner pulley bolt, and then remove the timing belt.
[B] CAMSHAFT SPROCKET REMOVAL
1. While holding the camshaft sprocket with special tools MB990767 and MD998715, loosen the camshaft sprocket bolt.
2. Remove the camshaft sprocket.
INSTALLATION SERVICE POINT
[A] CAMSHAFT SPROCKET INSTALLATION
1. Fit the camshaft sprocket to the front end of the camshaft.
2. While holding the camshaft sprocket with special tools MB990767 and MD998715, tighten the camshaft sprocket bolt.
Tightening torque: 88 ± 10 Nm (65 ± 7 ft-lb)
[B] CRANKSHAFT SENSING BLADE / CRANKSHAFT SPACER / CRANKSHAFT SPROCKET INSTALLATION
1. Clean the hole in the crankshaft sprocket.
2. Clean and degrease the mating surfaces of the crankshaft sprocket, sensing blade, and spacer.
NOTE: Degreasing is necessary to prevent decrease in friction on the mating surfaces.
3. Align the location of pin and pin hole, and then apply equal force in the direction of the arrow.
CAUTION
Do not bend the sensing blade when installing sprocket.
4. Install the crankshaft sprocket to the crankshaft.
[C] AUTO-TENSIONER INSTALLATION
CAUTION
Always bleed the auto-tensioner of air before installing the auto-tensioner.
NOTE: The auto-tensioner made by NTN Corporation has the NTN mark in the position shown in the illustration.
[D] TIMING BELT INSTALLATION
CAUTION
Do not turn the camshaft when the piston in No.1 cylinder is at top dead center on the compression stroke. Doing so can cause the lifted valve to hit against the piston, damaging parts.
1. Install special tool MD998769 and the crankshaft pulley washer, and then tighten the crankshaft bolt.
2. Align the timing mark on the crankshaft sprocket with the timing mark on the oil pump case, and then rotate the sprocket three teeth counterclockwise.
3. Align the timing mark on the left bank camshaft sprocket with the timing mark on the rocker cover.
4. Align the timing mark on the right bank camshaft sprocket with the timing mark on the rocker cover.
NOTE: Align the timing mark, on the right bank, with F.
5. Align the timing mark on the crankshaft sprocket with the timing mark on the oil pump case.
6. Install the timing belt on each sprocket and pulley in the following sequence. Do not leave the belt slack between each sprocket and pulley.
1) Crankshaft sprocket
2) Idler pulley
3) Left bank camshaft sprocket
4) Water pump pulley
5) Right bank camshaft sprocket
6) Tensioner pulley
7. Install special tool MD998767 to the tensioner pulley. While pushing the pulley lightly against the belt using the special tool, tighten the flange bolt.
Tightening torque: 48 ± 6 Nm (35 ± 4 ft-lb)
8. Check to see that the timing marks of all the sprockets are in alignment.
9. Rotate the crankshaft a quarter turn counterclockwise. Then rotate it back clockwise to verify that all the timing marks are aligned.
10. Loosen the flange bolt securing the tensioner pulley, and then mount special tool MD998767 and a torque wrench on the tensioner pulley.
11. Torque it to 4.4 Nm (39 in-lb) with the torque wrench.
12. While holding the tensioner pulley in position, tighten the flange bolt to the specified torque.
Tightening torque: 48 ± 6 Nm (35 ± 4 ft-lb)
13. Rotate the crankshaft two turns clockwise and leave it alone for approximately five minutes.
14. Check to see whether the metal wire inserted when the auto-tensioner was installed can be removed without any resistance.
If the metal wire can be removed without any resistance, it means that the belt has a proper tension. Therefore, remove the metal wire. In this condition, check that the rod protrusion of the auto-tensioner is within the standard value.
Standard value: 4.8 - 6.0 mm (0.19 - 0.24 inch)
15. If the metal wire offers resistance when removed, repeat the previous steps 10 through 13 until proper belt tension is obtained.
[E] ENGINE SUPPORT BRACKET, RIGHT INSTALLATION
The mounting bolts of the right engine support bracket must be tightened in the order shown in the illustration.
Tightening torque: 45 ± 5 Nm (34 ± 3 ft-lb)
Bolt length
85 mm (33.5 inch) - Bolt 3
95 mm (37.4 inch) - Bolts 2 and 4
100 mm (39.4 inch) - Bolt 1
INSPECTION
TIMING BELT
Replace the belt if any of the following conditions exist.
1. Hardening of rubber backing. Back side is glossy without resilience and leaves no indent when pressed with fingernail.
2. Cracks on rubber back.
3. Cracks or peeling of canvas.
4. Cracks on tooth bottom.
5. Cracks on belt.
6. Abnormal wear of belt sides. Normal wear is indicated if the sides are sharp as if cut by a knife. Abnormal wear is indicated if the sides are ragged.
7. Abnormal wear on teeth.
Initial stage:
Canvas worn (fluffy canvas fibers, rubbery texture gone, white discoloration, canvas texture indistinct)
Final stage:
Canvas worn, exposing rubber (tooth width reduced)
8. Missing tooth.
TENSIONER PULLEY AND IDLER PULLEY
Turn the pulley. If it does not rotate smoothly, or develops noise or excessive play, replace the pulley.
AUTO-TENSIONER
1. Check the auto tensioner for oil leaks from the sealed sections. Replace it if there is a leak.
2. Check the rod end for wear and other wear and other damage. Replace the auto tensioner if necessary.
3. Measure the length of rod protrusion. If it deviates from the standard value, replace the auto tensioner.
Standard value: 13.5 - 14.5 mm (0.53 - 0.57 inch)
4. Measure the amount of the retraction when the rod is pressed with the force of 100 - 200 N (23 - 44 lb). If it deviates from the standard value, replace the auto tensioner.
Standard value: within 1.0 mm (0.04 inch)
AIR BLEEDING PROCEDURE OF AUTO-TENSIONER
When the auto tensioner is not kept with its rod upward, or when the set pin having mm (0.08 inch) is pulled out before the installation to the engine, carry out the air bleeding as follows.
CAUTION
^ If the lateral type press is used, the appropriate air bleeding is not carried out. Always use longitudinal type press.
^ To prevent damage to the auto tensioner, do not apply the load of 5,000 N (1,124 lb) or more.
^ To prevent damage to the auto tensioner, do not press the rod below the cylinder end plane.
1. Set the auto tensioner to the longitudinal type press as shown in the illustration.
2. Slowly press down the rod, two or three times, to the cylinder end plane.
3. When the rod protrusion has approximately 5 mm (0.20 inch), apply the load of 100 - 200N (23 - 44 lb). Check whether the auto tensioner has sufficient stiffness.
4. If the auto tensioner does not have sufficient stiffness, replace the auto tensioner.
5. Slowly pressing down the rod, insert the set pin having diameter 2mm (0.08 inch) through the hole to fix the auto tensioner.
CAUTION
To prevent the air from being incorporated, keep the auto tensioner with its rod upward after the air bleeding.