Timing Belt
REMOVAL AND INSTALLATIONRemoval Steps 1-21:
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
[In case that the amount of rod protrusion is 5 mm with the set pin inserted.]
If the auto-tensioner rod is fully extended, reset it as follows.
1. Clamp the auto-tensioner in the vise with soft jaws.
2. Push in the rod little by little with the vise until set hole A in the rod is aligned with hole B in the cylinder.
3. Insert a wire [1.4 mm (0.055 inch) in diameter] into the set holes. This auto-tensioner setting wire will be used during timing belt alignment.
4. Unclamp the auto-tensioner from the vise.
]]D[[ AUTO-TENSIONER INSTALLATION
[In case that the amount of rod protrusion is 1 mm with the set pin inserted.]
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. Push in the rod little by little with the longitudinal type press until set hole A in the rod is aligned with hole B in the cylinder.
3. Insert a wire [2 mm (0.08 inch) in diameter] into the set holes. This auto-tensioner setting wire will be used during timing belt alignment.
CAUTION
To prevent the air from being incorporated, keep the auto tensioner with its rod upward after the air bleeding.
]]E[[ TIMING BELT INSTALLATION
[In case that the amount of rod protrusion is 5 mm with the set pin inserted.]
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.
]]F[[ TIMING BELT INSTALLATION
[In case that the amount of rod protrusion is 1 mm with the set pin inserted.]
CAUTION
Do not turn the camshaft when the piston in Number 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. Lightly pressing the tensioner pulley against the belt, insert the hexagonal wrench having the width of 5 mm (0.2 inch) between the tensioner body and tensioner arm to temporarily tighten the center bolt.
8. Inserting the hexagonal wrench, loosen the center bolt of the tensioner pulley to install the special tool the torque wrench. Applying the torque of 4.4 Nm (39 in-lb) to prevent the tensioner pulley from rotating, tighten the center bolt to 48 ± 6 Nm (35 ± 4 ft-lb)
9. Check to see that the timing marks of all the sprockets are in alignment.
10. Rotate the crankshaft a quarter turn counterclockwise. Then rotate it back clockwise to verify that all the timing marks are aligned.
11. Loosen the flange bolt securing the tensioner pulley, and then mount special tool MD998767 and a torque wrench on the tensioner pulley.
12. Torque it to 4.4 Nm (39 in-lb) with the torque wrench.
13. While holding the tensioner pulley in position, tighten the flange bolt to the specified torque.
Tightening torque: 48 ± 6 Nm (35 ± 4 ft-lb)
14. Pull out set pin having [diameter]2 mm (0.08 inch) inserted into the auto tensioner.
CAUTION
If the hexagonal wrench is removed first, the timing belt would possibly become loose and come off the tooth.
15. Pull out the hexagonal wrench.
16. Rotate the crankshaft two turns clockwise and let it stand for approximately five minutes.
17. Check whether the amount of the rod protrusion of the auto tensioner is within the standard value.
Standard value: 4.8 - 6.0 mm (0.189 - 0.236 inch)
18. When it deviates from the standard value, carry out the tension adjustment of the tensioner pulley again to obtain the appropriate belt tension.
]]G[[ 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
[In case that the amount of rod protrusion is 5 mm with the set pin inserted.]
1. Check for oil leaks. If oil leaks are evident, replace the auto-tensioner.
2. Check the rod end for wear or damage and replace the auto-tensioner if necessary.
3. Measure the rod protrusion. If it is out of specification, replace the auto-tensioner.
Standard value: 12 mm (0.5 inch)
4. Press the rod with a force of 98 to 196 N (22 to 44 pounds) and measure the movement of the rod.
If the measured value is out of the standard value, replace the auto-tensioner.
Standard value: 1.0 mm (0.03 inch) or less
AUTO-TENSIONER
[In case that the amount of rod protrusion is 1 mm with the set pin inserted.]
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 (0.532 - 0.570 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
[In case that the amount of rod protrusion is 1 mm with the set pin inserted.]
When the auto tensioner is not kept with its rod upward, or when the set pin having [diameter]2 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 - 200 N (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]2 mm (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.
VALVE CLEARANCE ADJUSTMENT
Adjust the valve clearance as follows:
CAUTION
Rotate the crankshaft clockwise at any time.
1. Rotate crankshaft clockwise and then align the timing mark on the camshaft sprocket with the timing mark on the rocker cover. (Place Number 1 cylinder on the top dead center of compression stroke.)
NOTE: Align the timing mark, on the right bank, with F.
2. Remove the rocker cover.
3. Measure the valve clearances marked with arrows shown in the illustration.
A: When Number 1 cylinder is on the top dead center of compression stroke.
B: When Number 4 cylinder is on the top dead center of compression stroke.
4. Using a thickness gauge, adjust the clearance between the valve shaft end and the adjusting screw.
Standard value (in cold state): 0.10 mm (0.004 inch)
NOTE: After the engine assembly is installed on the vehicle, check the valve clearance again with the engine warmed up. Adjust if necessary.
5. Hold the adjusting screw with a screwdriver so it does not rotate then tighten the lock nut.
6. Rotate the crankshaft one time clockwise and then align the timing mark with the timing mark on the crankshaft sprocket. (Place Number 4 cylinder on the top dead center of compression stroke.)
7. Adjust the valve clearance for the rest of the valves.
8. Install the rocker cover.