Timing Belt: Service and Repair
REMOVAL
1. Remove the engine cover.
2. Using the spanner [16mm], rotate the tensioner arm clockwise (about 14°) and remove the belt from pulley.
3. Remove the coolant pump pulley, idler pulley, tensioner pulley and crankshaft pulley.
4. Remove the upper and lower timing belt covers.
5. Support the engine with garage jack or wooden block and remove the engine mounting insulator.
6. Remove the engine mount bracket from the engine.
7. Remove the auto tensioner.
NOTE
- Rotate the crankshaft clockwise and align the timing mark to get the No.1 cylinder's piston to be in TDC position (compression stroke). At this time, the timing mark of camshaft sprocket and cylinder head cover should coincide each other.
8. Remove the timing belt.
NOTE
- When using the timing belt again, make sure of marking the rotating direction on the belt so as to install correctly.
INSPECTION
1. Closely inspect the belt. If the following problems are evident, replace the belt with a new one.
1) Hardened back surface rubber. Back surface glossy. Non-elastic and so hard that even if a finger nail is forced into it, no mark is produced.
2) Cracked surface rubber
3) Side of belt badly worn
NOTE
- A belt in good condition should have clear-cut sides as if cut with a sharp knife.
4) Teeth badly worn
Initial stage:
Canvas on the load side of the tooth flank worn (fluffy canvas fibers, rubber gone and color changed to white, unclear canvas texture)
Last stage:
Canvas on the load side of the tooth flank worn down and rubber exposed (tooth width reduced)
5) Missing tooth
2. If backlash or an irregular noise is observed when rotating the pulley, replace the timing belt tensioner and idler pulley.
INSTALLATION
The method of installing Timing belt and Auto tensioner.
1. Install idler pulley to water pump boss.
NOTE
- Insert and install idler pulley to the pin spring that is pressed and inserted in the water pump boss.
2. Install tensioner arm and plane washer to cylinder block.
3. Install tensioner pulley to the tensioner arm.
4. Install sprockets and align the timing mark.
NOTE
- When installing camshaft sprocket, fasten the sprocket tightly with holding the hexagonal part of the camshaft.
- Before installing timing belt, if the timing marks of cam sprocket and cylinder head cover do not coincide, do not rotate the cam sprocket more than 3 teeth of sprocket in any direction. Rotating sprocket more than 3 teeth might make valve and piston touch each other.
- In case of rotating the cam sprocket unavoidably more than 3 teeth, rotate the cam sprocket after rotating 3 teeth in the side of crank counter-clockwise on the base of timing mark.
5. Install the auto tensioner to the front case.
NOTE:
- At this time auto tensioner's set pin should be assembled completely.
6. Align the timing marks of each sprocket and install the timing belt in this order.
Crankshaft sprocket - Idler pulley - Intake cam sprocket (LH side) - Water pump pulley - Intake cam sprocket (RH side) - Tensioner pulley.
NOTE
- In this step, No.1 is in TDC (Compression stroke). Do not insert fingers.
7. Pull out the set pin of the auto tensioner.
8. Install the engine mount bracket from the engine.
9. Install the engine mounting insulator.
10. Install the upper and lower timing belt covers.
11. Install the coolant pump pulley, idler pulley, tensioner pulley and crankshaft pulley.
12. Using the spanner [16mm], rotate the tensioner arm clockwise (about 14°) and install the belt from pulley.
13. Install the engine cover.
14. Install the oil filler cap.
The method to adjust the tension of timing belt.
1. Rotate the crankshaft in 2 turns clockwise and measure the projected load of auto tensioner in the TDC (# 1 Compression stroke) after 5 minutes.
2. Check the projected length is 6-8 mm.
3. Check again if the timing marks of each sprocket are in specified position.
NOTE
- If not within specified position, do again from procedure 6 in the method of installing Timing belt and auto tensioner.