Timing Belt: Service and Repair
DISASSEMBLY
1. Loosen the coolant pump pulley bolt.
2. Loosen the generator bolt.
3. Remove the coolant pump pulley and belt.
4. Remove the crankshaft pulley.
5. Remove the timing belt cover.
6. Move the timing belt tensioner pulley toward the coolant pump and temporarily secure it.
7. Remove the camshaft from the camshaft sprocket.
8. Remove the camshaft sprocket.
9. Remove the timing belt.
NOTE: If the timing belt is reused, make an arrow mark indicating the turning direction (or the front of the engine) to make sure that the belt is reinstalled in the same direction as before.
10. Remove the crankshaft sprocket bolts. Remove the crankshaft sprocket and flange.
11. Remove the timing belt tensioner.
INSPECTION
Timing Belt
1. Check the belt for oil or dust deposits. Replace, if necessary. Small deposits should be wiped away with a dry cloth or paper. Do not clean with solvent.
Part 1 Of 2:
Part 2 Of 2:
2. When the engine is overhauled or belt tension adjusted, carefully check the belt. If any of the following flaws are evident, replace the belt.
Sprockets and Tensioner
1. Check the camshaft sprocket, crankshaft sprocket, tensioner pulley, and idler pulley for abnormal wear, cracks, or damage. Replace as necessary.
2. Inspect the tensioner pulley and the idler pulley for easy and smooth pulley rotation and check for play or noise. Replace as necessary.
TENSIONER INSTALLATION PROCEDURE
1. Temporarily fasten timing belt tensioner in such position as to place it's pulley nearest to the coolant pump (pulley may touch coolant pump body)
2. After installing the tensioner, the crankshaft sprocket and the camshaft sprocket, match the timing mark of each sprocket as shown in the illustration. Rotate the crankshaft until the No. 1 cylinder is at top dead center on the compression stroke.
CAUTION:
1) Be sure to install the flange in the correct direction (Chamfered part shows front of engine).
2) When installing the camshaft sprocket, make sure that the pin on the camshaft fits small hole in pulley.
NOTE:
Allow tensioner to remain in assemble state and must be installed temporarily as follows.
1) Temporarily tighten the tensioner as shown in illustration, in state that one extended end of spring tensioner is assembled to bend of tensioner bracket as imaginary line (wheel spring tensioner is inoperative and not loaded).
2) Then set extended end of tensioner spring at front case with drive etc.
3. Install the timing belt so as not to allow slack to the tension side. Make sure that all timing marks are at their correct position with the tension side in a strained state by applying force to the camshaft sprocket in a counterclockwise direction.
REASSEMBLY
1. Install the flange and crankshaft sprocket as shown. Pay close attention to their mounting directions.
Tightening torque:
Crankshaft sprocket bolt: 140-150 Nm (1400-1500 kg.cm, 103-110 ft. lbs.)
2. Install the camshaft sprocket and tighten the bolt to the specified torque.
Tightening torque:
Camshaft sprocket bolt: 80-100 Nm (800-1000 kg.cm, 59-74 ft. lbs.)
3. Align the timing marks of the camshaft sprocket and crank shaft sprocket, with the No.1 piston placed at top dead center on its compression stroke.
4. To install the timing belt tensioner, first mount the tensioner, spring, and spacer. Temporarily tighten the bolts. Next, temporarily tighten the tensioner long hole side washer and bolts. Install the bottom end of the spring against the front case as shown in the illustration.
5. Secure the tensioner, postponed towards the water pump.
6. Install the timing belt on the crankshaft sprocket.
7. Install the timing belt on the camshaft sprocket. When the timing belt is installed on the camshaft sprocket, make sure that the tension side is tight. Then, check to ensure that when the tension side is tightened by turning the camshaft sprocket in a reverse direction, all timing marks are in line.
8. Loosen the tensioner mounting bolts 1 and 2 in that order as shown. This will apply spring tension to the timing belt only. Check the belt to ensure that it is not out of position.
9. Tighten the tensioner tightening bolts 1 and 2 in that order. If the bolt 1 is tightened first, the tensioner will move with the belt in the direction that the belt is tightened.
10. Give the crankshaft one turn in operating direction (clockwise) and realign crankshaft sprocket timing mark with the top dead center position.
CAUTION: Do not turn the crankshaft in a counterclockwise direction. The crankshaft should turn smoothly.
11. Loosen the tensioner attaching bolt 1 and 2 in that order.
12. Tighten the tensioner attaching bolts 2 and 1 in that order to the specified torque.
Tightening torque:
Tensioner attaching bolt: 20-27 Nm (200-270 kg.cm, 14-20 ft. lbs.)
13. Then recheck the belt tension. Verify that when the tensioner and the tension side of the timing belt are pushed in horizontally with a moderate force [approx. 49 N (11 lbs.)], the timing belt cog end is approx. 1/2 of the tensioner mounting bolt head radius (across flats) away from the bolt head center.
14. Install the timing belt cover.
Tightening torque:
Timing belt cover bolt: 10-12 Nm (100-120 kg.cm, 7-9 ft. lbs.)
15. Install the crankshaft pulley. In the case, make sure that the crankshaft sprocket pin fit the small hole in the pulley.
16. Install the fan belt and adjust the belt tension.
17. Install the water pump pulley
18. Install V-belt and adjust the belt tension.
TENSION MEASURING PROCEDURE WHEN USING A TENSION GAUGE
1. Rotate the crankshaft in a counterclockwise direction to position of 90 degrees before top dead center as shown in the illustration.
NOTE: Make sure the valves are adjusted properly
2. Measure the belt tension in the middle of the tension side span using the tension gauge. (BORROUGHS BT-33-73F TYPE)
Timing belt tension (In cool condition): 9.5-16.5 Kg (20.9-36.4 lbs.)
CAUTION:
1) Put arm on bottom of belt teeth. And put spindle on the middle of belt back surface.
2) Keep hand off from indicating part.