Timing Belt

REMOVAL AND INSTALLATION

Removal Service Points
[A] Timing Belt Removal





1. Mark the belt running direction for reference in reinstallation.

NOTE:
1. Water or oil on the belt shorten its life drastically, so the removed timing belt, sprocket, and tensioner must be free from oil and water. These parts should not be washed. Replace parts if seriously contaminated.
2. If there is oil or water on each part check front case oil seals, camshaft oil seal and water pump for leaks.





[B] Oil Pump Sprocket Removal





[C] Crankshaft Bolt Loosening





[D] Crankshaft Sprocket Removal

[E] Timing Belt "B" Removal





1. Make a mark on the back of the timing belt indicating the direction of rotation so it may be reassembled in the same direction if it is to be reused.

NOTE:
1. Water or oil on the belt shortens its life drastically, so the removed timing belt, sprocket, and tensioner must be free from oil and water. These parts should not be washed. Replace parts if seriously contaminated.
2. If there is oil or water on each part, check front case oil seals, camshaft oil seal and water pump for leaks.





[F] Counterbalance Shaft Sprocket Removal





[G] Crankshaft Sprocket "B" Removal

[H] Camshaft Sprocket Bolt Loosening








1. Using a wrench, hold the camshaft at its hexagon (between the No. 2 and No. 3 journals) and remove the camshaft sprocket bolt.

CAUTION: Locking the camshaft sprocket with a tool damages the sprocket.

2. Remove the camshaft sprockets.

Installation Service Points
]A[ Camshaft Sprockets Tightening








1. Using a wrench, hold the camshaft at its hexagon (between the No. 2 and No. 3 journals) and tighten the bolt to the specification.

CAUTION: Locking the camshaft sprocket with a tool damages the sprocket.

]B[ Engine Support Bracket Installation





1. Coat the bolts illustrated with sealant before tightening.
Specified sealant: 3M ATD Part No. 8660 or equivalent

]C[ Sealant Application On Semi-Circular Packing








Specified sealant: 3M ATD Part No. 8660 or equivalent

]D[ Sealant Application On Rocker Cover





Apply the specified sealant to the areas indicated in the illustration.
Specified sealant: 3M ATD Part No. 8660 or equivalent

]E[ Spacer Installation





1. Install the spacer with the chamfered end facing toward the oil seal.





]F[ Counterbalance Shaft Sprocket Installation

]G[ Timing Belt "B" Installation





1. Align timing marks on the crankshaft sprocket "B" and counterbalance shaft sprocket with the marks on the front case respectively.
2. Install the timing belt "B" on the crankshaft sprocket "B" and counterbalance shaft sprocket. There should be no slack on the tension side.





3. Make sure that the relationship between the tensioner pulley center and the bolt center is as shown in the illustration.





4. Move the tensioner "B" in the direction of arrow while lifting with a finger to give a sufficient tension to the tension side of timing belt. In this condition, tighten bolt to secure tensioner "B". When the bolt is tightened, use care to prevent shaft from turning together. If shaft is turned together, belt will be overtensioned.





5. Check to ensure that timing marks on sprockets and front case are in alignment.
6. Press with index finger the center of span on tension side of timing belt "B". The belt must deflect 5 - 7 mm (0.20 - 0.28 inch).





]H[ Crankshaft Bolt Tightening

]I[ Oil Pump Sprocket Installation





1. Insert a Phillips screwdriver [shank diameter 8 mm (0.31 inch) shaft] through the plug hole on the left side of the cylinder block to block the left counterbalance shaft.
2. Install the oil pump sprocket.
3. Apply a proper amount of engine oil to the bearing surfaces of the nuts.
4. Tighten the nuts to the specified torque.

]J[ Auto Tensioner Installation





1. If the auto tensioner rod is in its fully extended position, reset it as follows.
2. Clamp the auto-tensioner in the vise with soft jaws.





3. Push in the rod little by little with the vise until the set hole A in the rod is aligned with the hole B in the cylinder.
4. Insert a wire [1.4 mm (0.055 inch) in diameter] into the set holes.
5. Unclamp the auto tensioner from the vise.





6. Install the auto tensioner to front case and tighten to the specified torque.

CAUTION: Leave the wire installed in the auto tensioner.

]K[ Tensioner Pulley Installation





1. Install the tensioner pulley in such direction that its two small holes are arranged vertically.

]L[ Timing Belt Installation





1. Turn the two sprockets so that their dowel pins are located on top. Then, align the timing marks facing each other with the top surface of the cylinder head. When you let go of the exhaust camshaft sprocket, it will rotate one tooth counterclockwise. This should be taken into account when installing the timing belt on the sprockets.





NOTE: The same camshaft sprocket is used for the intake and exhaust camshafts and is provided with two timing marks. When the sprocket is mounted on the exhaust camshaft, use the timing mark on the right with the dowel pin hole on top. For the intake camshaft sprocket, use the one on the left with the dowel pin hole on top.





2. Align the crankshaft sprocket timing marks.
3. Align the oil pump sprocket timing marks (Engine with counterbalance shafts).





4. Insert a Phillips screwdriver [shank diameter 8 mm (0.31 inch)] through the hole. If it can be inserted as deep as 60 mm (2.4 inch) or more, the timing marks are correctly aligned. If the inserted depth is only 20 - 25 mm (0.8 - 1.0 inch), turn the oil pump sprocket one turn and realign timing marks. Then check to ensure that the screwdriver can be inserted 60 mm (2.4 inch) or more. Keep the screwdriver inserted until the installation of the timing belt is finished.

NOTE: Step 4 is performed to ensure that the oil pump sprocket is correctly positioned with reference to the counterbalance shafts.





5. Thread the timing belt over the intake side camshaft sprocket and fix it at indicated position by a bulldog clip.





6. Thread the timing belt over the exhaust side sprocket, aligning the timing marks with the cylinder head top surface using two wrenches.





7. Fix the belt at indicated position by a bulldog clip.





8. Thread the timing belt over the idler pulley, the oil pump sprocket, the crankshaft sprocket and the tensioner pulley in the order shown.
9. Remove the two clips.





10. Lift up the tensioner pulley in the direction of arrow and tighten the center bolt.
11. Check to see that all timing marks are lined up.
12. Remove the screwdriver inserted in step 4 and fit the plug. (Engine with counterbalance shafts)
13. Give the crankshaft a quarter counterclockwise turn. Then, turn it clockwise until the timing marks are lined up again.





14. Install the special tools, Socket Wrench and Torque Wrench, on the tensioner pulley, and loosen the tensioner pulley center bolt.

NOTE: If the special tool is not available, use a commercially available torque wrench that is capable of measuring 0 - 5 Nm (0 - 3.6 ft. lbs.).

15. Torque to 3.6 Nm (2.60 ft. lbs.) with the torque wrench.
16. Holding the tensioner pulley with the special tool and torque wrench, tighten the center bolt to specification.





17. After giving two clockwise turns to the crankshaft, let it alone for approximately 15 minutes. Then, make sure that the auto tensioner setting wire moves freely.

NOTE: If the wire does not move freely repeat step 13 above until it moves freely.

18. Remove the auto tensioner setting wire.





19. Measure the distance "A" (between the tensioner arm and auto tensioner body).
Standard value: 3.8 - 4.5 mm (0.15 - 0.18 inch)

INSPECTION

Timing Belt





Replace belt if any of the following conditions exist.
1. Hardening of back rubber.
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 rib root.
5. Cracks on belt sides.





6. Abnormal wear of belt sides. The sides are normal if they are sharp as if cut by a knife.





7. Abnormal wear on teeth.
8. Missing tooth.

Auto Tensioner





1. Check the auto tensioner for possible leaks and replace as necessary.
2. Check the rod end for wear or damage and replace as necessary.
3. Measure the rod protrusion. If it is out of specification, replace the auto tensioner.
Standard value: 12 mm (0.47 inch)





4. Press the rod with a force of 98 to 196 N (22 to 44 ft.) and measure its protrusion.
5. If the measured value is 1 mm (0.39 inch) or more shorter than the value obtained in step (3), replace the auto tensioner.