Timing Belt: Service and Repair

TIMING BELT REPLACEMENT






CAUTION: a. Do not bend or twist timing belt.
b. After removing timing belt, do not turn crankshaft and camshaft separately because valves will strike piston heads.
c. Make sure that timing belt, camshaft sprocket, crankshaft sprocket, idler pulley and auto-tensioner are clean and free of oil and water.

Removal

1. Remove engine under cover.
2. Drain coolant from both cylinder block drain plugs, and radiator drain cock.






3. Remove radiator.
4. Remove drive belts, cooling fan and coupling.









5. Remove crankshaft pulley bolt.
At this time remove starter motor and set a suitable tool to ring gear so that crankshaft cannot rotate.






6. Remove crankshaft pulley using Tool.
7. Remove water inlet and outlet.






8. Remove front timing belt covers.






9. Install a suitable stopper bolt into tensioner arm of auto-tensioner so that projection of auto-tensioner pusher does not change.






10. Set No.1 cylinder at TDC on its compression stroke.
11. Remove auto-tensioner and timing belt.

Caution: a. Do not bend timing belt
b. After removing timing belt, do not turn crankshaft and camshaft separately because valves will strike piston heads.
c. Make sure that timing belt, camshaft sprocketm crankshaft sprocket, idler pully and auto-tensioner are clean and free of oil and water.

Inspection






1. Visually check the condition at timing belt. Replace if any abnormality is found.






2. Inspect auto-tensioner for oil leaks from pusher rod and diaphragm.

Installation

1. Confirm that No.1 cylinder is set at TDC on its compression stroke.






2. Align matching marks on camshaft and crankshaft sprockets with aligning marks on rear belt cover and oil pump housing.
3. Remove all spark plugs.






4. Check clearance between tension arm and pusher of auto-tensioner is 4 mm (0.16 in)
If not, adjust tensioner arm to give 4 mm (0.16 in) clearance with pusher of auto-tensioner using a suitable vise. and then insert stopper bolt into tensioner arm in order that clearance does not change.

NOTE: When adjusting clearance, do not push tensioner arm with stopper bolt fitted because it will damage thread portion of stopper bolt.






5. Install auto-tensioner and tighten nut 1 and bolts 2 & 3 slightly by hand.






6. Set timing belt.

a. Ensure timing belt and sprockets are clean and free from oil or water. Do not bend or twist timing belt.
b. Align white lines on timing belt with matching mark on camshaft sprocket and crankshaft sprocket.
c. Point arrow on timing belt towards the front.






7. Push auto-tensioner slightly towards timing belt to prevent bell from slipping.
Set tensioner slightly by pushing timing belt. Then, turn crankshaft 10° clockwise and tighten nut 1 and bolts 2 & 3 to 16 - 21 Nm (12 - 15 ft lb).

NOTE: At this time, do not push auto-tensioner hard or belt will be adjusted too tightly.






8. Turn crankshaft 120° counterclockwise.
9. Loosen nut 1 and bolts 2 & 3 1/2 turn to set tensioner body as far back as it will go.
10. Turn crankshaft clockwise and set No. 1 cylinder at TDC on its compression stroke.






11. Push the end of pusher with approx. 67.7 -81.4 N (6.9 - 8.3 kg, 15.2 - 18.3 lb) force using Tool (push-pull gauge) and tighten nut (1) and bolts (2) & (3) to 16 - 21 N.m (1.6 - 2.1 kg-m. 12 - 15 ft.lb.).

NOTE: If deflection of timing belt exceeds specification in procedure 15., change applied pushing force.






12. Turn crankshaft 120° clockwise.
13. Turn crankshaft 120° counterclockwise and set No. 1 cylinder at TDC on its compression stroke.






14. Prepare a suitable steel plate to measure belt deflection as shown.






15. Set plate and push it with 49 N (5 kg, 11 lb) force using Tool (push-pull gauge) at each position of timing belt mid-way between pulleys as shown.

Deflection: 6 - 7 mm (0.24 - 0.28 in) or the average of each portion (a)+(B)+(C)+(D) / 4 = 6 - 7 mm (0.24 - 0.28 in)

If not within specification, repeat procedure from step 7 through step 15.

16. Confirm auto tensioner fixing nuts and bolts are tightened to 16 - 21 N.m (1.6 - 2.1 kg-m, 12 - 15 ft lb).






17. Remove the auto-tensioner stopper bolt. After 5 minutes check the projection of the rod (clearance between tensioner arm and pusher) stays at 3.5 - 5.2 mm (0.138 - 0.205 in).






18. Check the proper installation (no slip or misplacement) of timing belt at each position as shown.






19. Install timing belt covers.