Overhaul

OVERHAUL
- Remove left and right hand cylinder heads.

Cylinder Liner Retainers:

- Immediately after each cylinder head has been removed, JD 41 cylinder liner retainers must be fitted to the engine between every other pair of cylinders. Failure to carry out this operation will result in the Hylomar seal at the bottom of the liner, being broken, causing water leakage into the oil pan.

NOTE: Always support the cylinder heads on blocks of wood. This will prevent damage to the valves which, when open, protrude below the cylinder head face.

- Remove the spark plugs and exhaust manifolds from the cylinder head.

DISASSEMBLY
- Gradually loosen each camshaft cap securing nut (two turns at a time) until the valve springs are fully relaxed.
- Note the cap to carrier relationship.
- Remove the nuts/washers and lift off the bearing caps.
- Remove the camshaft.

Tappet Removal:

- Using a magnet lift out the cam followers.
- Remove the camshaft carrier and remove all traces of sealant from carrier and head faces.
- Support the valves using wooden blocks.
- Remove the valve springs, using JD6118C and adaptor JD 6118C-2.
- Retrieve the collars, cotters, and spring retaining plates.
- Remove the valves noting the relationship between valve and guide to be sure of correct pairing during re-assembly.
- Remove the seals from the inlet valve guides.
- Clean all component parts.
- Clean the heads thoroughly and check them and cylinder block for warping, bowing or cracks.
- Check for wear and burning of valves or seats.
- Check the cylinder head face for distortion.
- If distortion is evident, a maximum of 0.025 mm (0.010 in) may be removed by resurfacing the cylinder head.

CAUTION: If the heads are resurfaced, the finish MUST be extremely smooth. If not, it will leak between the gasket (a metal shim type), and the head. The head surface and the head gasket can be painted with dull aluminum spray paint to improve sealing.

^ For valve guide service, refer to CYLINDER HEAD / VALVE GUIDE.
^ For valve seat service, refer to CYLINDER HEAD / VALVE SEAT.
^ For valve grinding service, refer to CYLINDER HEAD / VALVE GRINDING.
^ For cam follower service, refer to CYLINDER HEAD / CAM FOLLOWER (TAPPET).

ASSEMBLY
- Fit the valves into the guides and place the cylinder head on wooden blocks.
- Fit the valve spring seats, inlet valve guide oil seals, springs and collars.
- Compress the springs using J61 18B and Adaptor J61 18C-2 and insert the cotters.
- Apply Loctite 518 sealant to the camshaft carrier mating surface. Be careful NOT to allow sealent into tappet bore.
- Refit the cam carrier.
- Refit the original shims in the valve collar recesses.
- Be sure that the shims are seated correctly.
- Fit the cam followers.

NOTE: If the cylinder head has been overhauled to the extent of having the valve seats recut, each shim should be approximately 0.010 in. smaller than the original.

- Lubricate the camshaft and fit to the cam carrier ensuring that it is fitted with the slot to the top.
- Fit the camshaft caps and torque tighten the securing bolts in the sequence shown.
- Measure the valve clearance between the heel of the camshaft and the cam followers, turning the camshaft as necessary to measure all the clearances. The correct clearance should be:

Inlet and Exhaust 0.031 to 0.036 mm (O.012-O.014in).

- Refer to ADJUSTMENT PROCEDURES / VALVES for adjusting procedure.

NOTE: When both heads are finished, a final check of the valve clearances should be done before the heads are fitted to the cylinder block.

- To refit cylinder heads, refer to CYLINDER HEAD / REMOVE AND REFIT.

TORQUE FIGURES

Air pump adjuster bolt/locknut 2O-27 Nm
Banjo connector bolts 12-14 Nm
Bearing caps to carrier 11-13.5 Nm
Camshaft sprocket to camshaft 23-27 Nm
Camshaft cover 11 Nm
Cylinder head to block (9/16"AF) 36 Nm
Cylinder head to block (5/8"AF) 70 Nm
EGR valve to throttle housing 9.5-12 Nm
Elbow to inlet manifold 12.2 Nm
Exhaust manifold to cylinder head 23-27 Nm
Fan/clutch to water pump 23-27 Nm
Exhaust down pipe to manifold 30-35 Nm
Heat shield to manifold 23-27 Nm
Hose clips 2.5 Nm
Inlet manifold to cylinder head (nuts) 23-27 Nm
Inlet manifold to cylinder head (bolts) 23-27 Nm
Silencer to compressor union 34 Nm
Spark plugs (taper seat) 9.5Nm-12.5 Nm
Thermostat housing to cylinder head 23-27 Nm