Rocker Arm Assembly: Service and Repair
Rocker Arms, Rocker Arm Shaft and Camshaft
REMOVAL
1. Disconnect negative cable at battery.
2. Remove timing belt as previously outlined and remove camshaft timing belt pulley by using special tool.
Special Tool
(A): 09917-68220
3. Remove cylinder head cover as previously outlined.
4. Disconnect CMP sensor coupler from CMP sensor.
5. Remove CMP sensor case from cylinder head. Place a container or rag under CMP sensor case, for a small amount of oil flows out during removal of case.
6. After loosening all valve adjusting screw lock nuts, turn adjusting screws back all the way to allow all rocker arms to move freely.
7. Remove camshaft housing and camshaft.
NOTE: To remove camshaft housing bolts, loosen them in such order as indicated in figure, a little at a time.
8. Remove timing belt inside cover.
9. Remove intake rocker arm with clip from rocker arm shaft.
NOTE: Do not bend clip when removing intake rocker arm.
10. Remove rocker arm shaft bolts.
11. Remove exhaust rocker arms and rocker arm spring by pulling out rocker arm shaft to battery side after removing battery.
INSPECTION
Adjusting Screw and Rocker Arm
If tip of adjusting screw is badly worn, replace it. Rocker arm must be replaced if its cam-riding face is badly worn.
Rocker Arm Shaft Runout
Using "V" blocks and dial gauge, check runout. If runout exceeds its limit, replace rocker arm shaft.
Runout limit: 0.20 mm (0.008 inch)
Rocker Arm-to-Rocker Arm Shaft Clearance
Using a micrometer and a bore gauge, measure rocker shaft diameter and rocker arm I.D.
Difference between two readings is arm-to-shaft clearance on which a limit is specified.
If limit is exceeded, replace shaft or arm, or both.
Cam Wear
Using a micrometer, measured height of cam. If measured height is below limit, replace camshaft.
Camshaft Runout
Hold camshaft between two "V" blocks, and measure runout by using a dial gauge.
If runout exceeds the limit, replace camshaft.
Runout limit: 0.10 mm (0.0039 inch)
Camshaft Journal Wear
Check camshaft journals and camshaft housings for pitting, scratches, wear or damage.
If any malcondition is found, replace camshaft or cylinder head with housing. Never replace cylinder head without replacing housing.
Check clearance by using gaging plastic.
The procedure is as follows.
1. Clean housing and camshaft journals.
2. Install camshaft to cylinder head.
3. Place a piece of gaging plastic the full width of journal of camshaft (parallel to camshaft).
4. Install camshaft housing.
5. Tighten camshaft housing bolts in such order as indicated in figure a little at a time till they are tightened to specified torque.
Tightening Torque
(a): 11 Nm (1.1 kg-m, 8.0 ft. lbs.)
NOTE: Do not rotate camshaft while gaging plastic is installed.
6. Remove housing and using scale on gagine plastic envelope, measure gaging plastic width at its widest point.
If measured camshaft journal clearance exceeds limit, measure journal (housing) bore and outside diameter of camshaft journal. Replace camshaft or cylinder head assembly whichever the difference from specification is greater.
INSTALLATION
1. Apply engine oil to rocker arm shaft and rocker arms.
2. Check O-ring for damage or deterioration. Install O-ring to rocker arm shaft.
3. Install rocker arm shaft with its holes facing up, rocker arm (exhaust side) and rocker arm spring.
4. Install rocker arm shaft bolts and tighten them to specified torque.
Tightening Torque
(a): 11 Nm (1.1 kg-m, 8.0 ft. lbs.)
5. Fill small amount of engine oil into arm pivot holding part of rocker arm shaft. Install rocker arm (intake side) with clips to rocker arm shaft.
6. Apply engine oil to cams and journals on camshaft and put camshaft on cylinder head. Install camshaft housing to camshaft and cylinder head.
^ Apply engine oil to sliding surface of each housing against camshaft journal.
^ Apply sealant to mating surface of No. 6 housing which will mate with cylinder head.
"A" Sealant: 99000-31110
^ Embossed marks are provided on each camshaft housing, indicating position and direction for installation. Install housing as indicated by these marks.
^ As camshaft housing No. 1 retains camshaft in proper position as to thrust direction, make sure to first fit No. 1 housing to No. 1 journal of camshaft securely.
^ After applying engine oil to housing bolts, tighten them temporarily first. Then tighten them by the sequence as indicated in figure. Tighten a little at a time and evenly among bolts and repeat tightening sequence three to four times before they are tightened to specified torque.
Tightening Torque
(a): 11 Nm (1.1 kg-m, 8.0 ft. lbs.)
7. Install camshaft oil seal. After applying engine oil to oil seal lip, press-fit camshaft oil seal till oil seal surface becomes flush with housing surface.
8. Install timing belt inside cover.
9. Install camshaft timing belt pulley to camshaft, while fitting pin on camshaft into slot at "E" mark.
10. Using special tool, tighten pulley bolt to specified torque.
Tightening Torque
(a): 60 Nm (6.0 kg-m, 43.5 ft. lbs.)
Special Tool
(A): 09917-68220
11. Install belt tensioner, timing belt, outside cover, crankshaft pulley and water pump belt as previously outlined.
12. After applying sealant to part "A", install CMP sensor case (Distributor less ignition coil case) to cylinder head and tighten its fixing bolts to specified torque.
"A" Sealant: 99000-31110
Tightening Torque
(a): 11 Nm (1.1 kg-m, 8.0 ft. lbs.)
13. Adjust valve clearance as previously outlined.
14. Install cylinder head cover and air cleaner outlet hose.
15. Check to ensure that the parts are back in place:
^ Ignition coil assemblies
^ High tension cords
^ CMP sensor coupler
^ Couplers to ignition coil assembly
^ Other removed parts which have not been reinstalled
16. Connect negative cable at battery.
17. Confirm that ignition timing is within specification.