Timing Belt: Service and Repair
REMOVAL
1. Remove the water pump drive belt and pulley.
2. Remove the cranking adapter and crankshaft pulley.
3. Remove the upper and lower timing belt covers.
4. Move tensioner fully toward water pump and temporarily secure tensioner.
5. If timing belt is to be reused, make an arrow mark which indicating turning direction to ensure that belt is reinstalled in same direction as before.
6. Remove the timing belt from the sprockets.
CAUTION:
- Place the belt in a clean, dry area where it will not be damaged by oil or water.
7. Remove the camshaft sprocket bolt and remove camshaft sprocket.
8. Remove the crankshaft sprocket bolt and then remove crankshaft sprocket and flange from the crankshaft.
9. Remove plug at left side of cylinder block and insert a screwdriver to keep left silent shaft in position. Screw- driver used for this purpose should have a shaft 8 mm (0.3 in.) in diameter which can be inserted more than 60 mm (2.36 in.).
10. Remove oil pump sprocket retaining nut and remove oil pump sprocket.
11. Loosen right silent shaft sprocket mounting bolt until it can be turned with fingers.
12. Remove tensioner "B" and remove timing belt "B".
CAUTION:
- After timing belt "B" has been removed, do not attempt loosening bolt, while holding sprocket with pliers, etc.
13. Remove the crankshaft sprocket "B" from crankshaft.
CLEANING BELT TRAIN PARTS
1. Do not immerse the timing belts or sprockets in cleaning solvent. Immersing the timing belt will damage rubber. Immersing the sprocket into cleaning solvent may cause solvent to soak into it. When the sprocket is used, the solvent will contact the belt and shorten its life. Wipe these parts with a cloth only.
2. Do not immerse the timing belt tensioners in cleaning solvent. Tensioner pulley is prelubricated at the factory; solvent will wash lubrication away. Wipe the tensioners with a cloth only.
INSPECTION
Timing Belt
Check the belt in detail. If following flaws are evident, replace 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) Cranked back surface rubber
(3) Cracked or exfoliated canvas
(4) Cracked tooth bottom
(5) Side of belt cracked
(6) Cracked or exfoliated canvas
(7) Side of belt badly worn
NOTE:
- Normal belt should have clear-cut sides as if cut with a sharp knife.
(8) Badly worn teeth,
Initial stage:
- Canvas on load side tooth flank worn (fluffy canvas fibers, rubber gone and color changed to white, and unclear canvas texture)
Last stage:
- Canvas on load side tooth flank worn down and rubber exposed (tooth width reduced)
(9) Missing tooth
Timing Belt Tensioners
1. Replace the timing belt tensioner if the pulley is damaged or feels rough when turning.
2. Replace the timing belt tensioner if there is grease leakage from the seal.
INSTALLATION
1. Install the crankshaft sprocket "B" into crankshaft. Be sure to install in the direction shown in the illustration.
2. Lightly apply engine oil to the outer surface of spacer, and then install spacer to the right silent shaft. Be sure to install in the direction shown in the illustration.
3. Install silent shaft sprocket onto right silent shaft, and then tighten flange bolt finger tight.
4. Install timing belt "B" and adjust the belt tension. See Timing Belt Installation Procedure" for detailed procedure.
5. Tighten the right silent shaft sprocket bolt to 34-40 Nm (25-29 ft.lbs.).
6. Install flange and crankshaft sprocket onto crankshaft. Be sure to install in the direction shown in the illustration.
CAUTION:
- Pay attention to direction of flange. If it is installed in wrong direction, a broken belt could result.
7. Install special washer and sprocket bolt to crankshaft, and then tighten the sprocket bolt to 110-130 Nm (80-94 ft.lbs.).
8. Install the camshaft sprocket to the camshaft and tighten bolt to 80-100 Nm (58-72 ft.lbs.).
9. Install spacer, tensioner and tensioner spring.
10. Install end "A" of spring to predetermined position of tensioner bracket.
11. Install end "B" of spring to predetermined position of water pump.
12. Install the timing belt and adjust the belt tension. See "Timing Belt Installation Procedure", steps 7 through 20.
13. Install the timing belt covers.
14. Install the crankshaft pulley and crankshaft compressor pulley, and then tighten bolts to 20-30 Nm (15-21 ft.lbs.).
Timing Belt Installation Procedure
1. Align timing mark on each sprocket with corresponding timing mark on front case.
When timing belt "B" is installed, make certain that tension side has no slack.
Install tensioner "B" with center of pulley located on left side of mounting bolt and with pulley flange directed toward front of engine.
Lift tensioner "B" with finger tip to tighten timing belt "B" so that its tension side will be taut. In this condition, tighten bolt to secure tensioner "B". When bolt is tightened, use care to prevent shaft from turning together. If shaft is turned together, belt will be overtensioned. Tighten the right silent shaft retaining flange bolt to 34-40 Nm (25-28 ft.lbs.).
5. Check to ensure that timing marks are in alignment.
6. Check to ensure that when center of span on tension side is depressed with index finger in direction of arrow, deflection of belt is up to specification.
Belt deflection: 5-7 mm (0.20-0.28 in.)
7. Move tensioner fully toward water pump and temporarily secure tensioner.
8. Align timing mark on camshaft sprocket with that on cylinder head.
9. Align timing mark on crankshaft sprocket with that on front case.
10. Align timing mark on oil pump sprocket with that on front case.
11. When timing mark on oil pump pulley is aligned with that on front case, be sure to remove plug on left side of cylinder block and insert a screwdriver having shaft 8 mm (0.3 in.) in diameter. If it can be inserted 60 mm (2.36 in.) or more, alignment is correct. If it can be inserted only 25 mm (.98 in.), turn oil pump sprocket through a turn and realign timing marks. Check to ensure that screwdriver can be inserted more than 60 mm (2.36 in.). Keep screwdriver inserted until installation of timing belt is finished.
12. Install timing belt. While making sure that tension side of belt is not slackened, install timing belt onto crankshaft sprocket, oil pump sprocket and camshaft sprocket in that order.
13. Loosen tensioner mounting bolt and nut. By so doing, tensioner will be moved by spring and will apply tension to belt.
14. Check that portion of belt which is indicated by arrow "A"to make sure that it is not floating up.
15. Tighten tensioner mounting nut and bolt. Tighten slot side bolt before tightening fulcrum side nut. If fulcrum side nut is tightened earlier, tension bracket will be turned together and belt will be overtensioned.
16. Check to ensure that timing marks on all sprockets are in alignment with respective timing marks.
17. Give a turn clockwise to crankshaft.
CAUTION:
- Do not turn crankshaft in reverse direction. Crankshaft should be turned smoothly clockwise.
18. Loosen tensioner mounting nut and bolt.
19. Tighten tensioner mounting nut and bolt. Be sure to tighten fulcrum side nut and bolt in Step 15.
20. Check to ensure that when center of belt span on tension side and seal line of under cover are held between thumb and forefinger as illustrated, clearance C between belt and seal line is as follows:
Clearance "C" between timing belt and seal line Approx. 14 mm (0.55 in.).