Camshaft and Cam Follower

REMOVAL
1. Remove the cylinder head cover fasteners.





2. Remove cylinder head cover from cylinder head.





3. Bearing caps are identified for location. Remove the outside bearing caps first.





4. Loosen the camshaft bearing cap attaching fasteners in sequence shown in one camshaft at a time.

CAUTION: Camshafts are not interchangeable. The exhaust cam number 6 bearing journal is wider.

5. Identify the camshafts before removing from the head. The cams are not interchangeable.
6. Remove cam follower assemblies from cylinder head. Keep the cam followers in the order they have been removed from the head for reassembly.
7. Mark hydraulic lash adjusters for reassembly in their original positions. Lash adjusters are serviced as an assembly.

CLEANING
Before installation, clean cylinder head and cover mating surfaces. Make certain the rails are flat.

INSTALLATION
1. Install hydraulic lash adjuster assembly making sure that adjusters are at least partially full of oil. This is indicated by little or no plunger travel when the lash adjuster is depressed.





2. Lubricate with clean oil and install cam follower assemblies in their original position on the hydraulic adjuster and valve stem.

CAUTION: Piston should NOT be at top dead center when installing the camshaft.

420A Engine:

3. Lubricate bearing journals and cams with clean oil and install the camshafts. Install right and left camshaft bearing caps No. 2 thru No. 5 and right No.6. Tighten M6 fasteners to 12 Nm (9 ft. lbs.) in sequence shown in the figure.





4. Apply Loctite 51817 to No. 1 and No. 6 bearing caps. Install bearing caps and tighten M8 fasteners to 28 Nm (21 ft. lbs.).
5. Bearing end caps must be installed before seals can be installed.
Install timing belt, sprockets and timing covers. Refer to Engine; Service and Repair; Engine Overhaul; Timing Belt.

CAUTION: Do not allow oil or solvents to contact the timing belt as they can deteriorate the rubber and cause tooth skipping.

7. Install new cylinder head cover gaskets.
8. Apply Loctite 18718 at the camshaft cap corners and at the top edge of the 1/2 round seal.





9. Install cylinder head cover assembly to head and tighten fasteners in sequence shown in the figure. Using the 3 step torque method:
Step 1 Tighten all fasteners to 4.5 Nm (3.3 ft. lbs.)
Step 2 Tighten all fasteners to 9.0 Nm (6.5 ft. lbs.)
Step 3 Tighten all fasteners to 12 Nm (9 ft. lbs.)

INSPECTION

Camshaft
1. Inspect camshaft bearing journals for damage and binding.
If journals are binding, also check the cylinder head bearing surface for damage, and check the camshaft bearing oil feed holes in the cylinder head for clogging.





2. Check the cam surface for abnormal wear and damage. Replace if defective. Also measure the cam height and replace if out of limit.
Standard value: 0.0254 mm (0.001 inch)
Limit: 0.254 mm (0.01 inch)
To measure cam lobe wear, measure lobe diameter in two places at the largest diameter (over the nose). Take first reading with micrometer in unworn area at the edge of the lobe. Take second reading in the worn area where cam follower contacts the lobe. Subtract second reading from the first. The difference is the cam lobe wear.

Cam Follower





1. Inspect the cam follower assembly for wear or damage. Replace as necessary.

Camshaft End Play
1. Oil camshaft journals and install camshaft without cam follower assemblies. Install rear cam caps and tighten screws to specified torque.
2. Using a suitable tool, move camshaft as far rearward as it will go.
3. Zero dial indicator.





4. Move camshaft as far forward as it will go.
End play standard value: 0.15 mm (0.006 inch)