REMOVAL & INSTALLATION
On cars with air conditioning, remove the mounting bolts and the drive belt, and position the compressor out of the way. Remove the compressor upper mounting bracket from the cylinder head.
6 Cylinder Engine
See Figure 1
- Disconnect the negative battery cable.
- Drain coolant into a container. Remove the air cleaner assembly.
- Unfasten the negative battery cable from the cylinder head.
- Disconnect the exhaust pipe at the manifold. Use wire to position exhaust system out of the way.
- Unfasten the accelerator retracting spring, choke control cable and accelerator rod at the carburetor.
- Disconnect the fuel line and distributor control vacuum line at the carburetor.
- Remove the coolant tubes from the carburetor spacer. Disconnect the coolant and heater hoses.
- Disconnect the distributor control vacuum line at the distributor and fuel inlet line at the filter. Remove all the lines as an assembly.
- On an engine equipped with positive crankcase ventilation, disconnect the emission exhaust tube.
- Disconnect and mark the spark plug wires at the plugs and the small wire from the temperature sending unit. On an engine equipped with a Thermactor® exhaust emission control system, disconnect the air pump hose at the air manifold assembly. Unscrew the tube nuts and remove the air manifold. Disconnect the anti-backfire valve air and vacuum lines at the intake manifold. On a car equipped with power brakes, disconnect the brake booster vacuum line at the intake manifold.
- Remove the rocker arm cover.
- Loosen the rocker arm nut so that the rocker arm can be rotated to one side. Remove the pushrods and keep them in sequence.
- Remove one cylinder head bolt from each end of the engine and install two 7 / 16 in. guide studs.
Guide studs can be purchased from an automotive tool supplier, or made by cutting the head off of several old head bolts.
- Remove the remaining cylinder head bolts, then remove the cylinder head.
- Prior to installation, clean the head and block surfaces of old gasket material.
- Apply sealer to both sides of the head gasket. Position the gasket over the guide studs or dowel pins.
Apply gasket sealer only to steel shim head gaskets. Steel/asbestos composite head gaskets are to be installed without any sealer.
- Install a new sealing gasket to the exhaust pipe flange.
- Lift the cylinder head over the guide studs and slide it carefully into place while guiding the exhaust manifold studs into the exhaust pipe flange.
- Coat cylinder head attaching bolts with water resistant sealer and install (but do not tighten), the head bolts.
- Tighten the head, according to the illustrated sequence in three progressive steps. Tighten the bolts to 50-55 ft. lbs. (68-74 Nm), then 60-65 ft. lbs. (81-88 Nm) and finally to 75 ft. lbs. (102 Nm).
- Lubricate both ends of the pushrods with oil and insert them in their original bores.
- Lubricate the valve stem tips and rocker arm pads with oil.
- Position the rocker arms and tighten the nuts enough to hold the pushrods in position.
- Do a preliminary, cold valve lash adjustment. Refer to the procedure in Engine Electrical .
- Install exhaust pipe-to-manifold nuts and lockwashers. Tighten to 17-22 ft. lbs. (23-30 Nm)
- Connect the radiator and heater hoses. Fasten the coolant tubes at the carburetor spacer.
- Connect the distributor vacuum line and the carburetor fuel line. Connect battery cable at the cylinder head.
- On engines equipped with positive crankcase ventilation, clean the components thoroughly and install.
- On engines equipped with a Thermactor® exhaust emission control system, install the air manifold assembly on the cylinder head, the air pump outlet hose to the air manifold, and the anti-backfire valve, air and vacuum lines to the intake manifold.
- Connect the accelerator rod pull-back spring. Fasten the choke control cable and the accelerator rod at the carburetor.
- Attach the distributor control vacuum line at distributor. Connect carburetor fuel line at fuel filter.
- Fasten the temperature sending unit wire at the sending unit. Connect spark plug wires.
- Completely fill the cooling system.
- Install valve/rocker arm cover, then the air cleaner assembly.
- Start the engine and allow it to reach normal operating temperature. Bleed the cooling system. Check for fluid leaks. Adjust engine idle speed. check valve lash and adjust, if necessary.
- Road test the vehicle for proper operation.
See Figures 2, 3, 4, 5, 6 and 7
Read the complete service procedure before starting this repair. On vehicle applications where there is a number of brackets and/or pulleys, component parts, etc., mark each item for correct installation.
- Drain the cooling system. Relieve fuel system pressure if fuel injected.
- Remove the intake manifold.
- Disconnect the spark plug wires, marking them as to their location Position them out of the way of the cylinder head. Remove the spark plugs.
- Disconnect the exhaust (pipes) at the exhaust manifold(s). Secure the pipe(s) out of the way using wire.
On some 5.8L and 6.6L engines, it may be necessary to remove the exhaust manifolds from the cylinder heads to gain access to the lower head bolts.
- Disconnect the negative battery cable at the cylinder head (if applicable).
- On cars with air conditioning, position the compressor out of the way of the cylinder head. Remove the compressor upper mounting bracket from the cylinder head.
- In order to remove the left cylinder head on cars equipped with power steering, it may be necessary to remove the steering pump and bracket. Remove the drive belt, then secure the steering pump out of the way.
- In order to remove the left cylinder head on a car equipped with Thermactor® exhaust emission control system, disconnect the hose from the air manifold on the left cylinder head.
- In order to remove the right cylinder head, it may be necessary to remove the alternator mounting bracket bolt and spacer, the ignition coil, and the air cleaner inlet duct from the right cylinder head.
- If the right cylinder head is to be removed on a car equipped with a Thermactor® exhaust emission control system, remove the Thermactor® air pump and its mounting bracket. Disconnect the hose from the air manifold on the right cylinder head.
- On 6.4L and 7.0L engines, unbolt the rocker arm shafts from front to back, two turns at a time, and remove the rocker shaft and arm assembly. On all other V8 engines, loosen the rocker arm stud nuts or mounting bolts enough to rotate the rocker arms to one side in order to facilitate the removal of the pushrods. On all V8 engines, remove the pushrods in sequence and number them, so that they may be installed in their original positions.
- Remove the cylinder head attaching bolts, noting their positions. Lift the cylinder head off the block. Remove and discard the old cylinder head gasket.
- Prior to installation, clean all surfaces of old gasket material. These include the cylinder head, intake manifold, rocker arm (valve) cover, and the cylinder block contact surfaces.
- Position the new cylinder head gasket over the cylinder dowels on the block. Coat the head bolts with water resistant sealer. Position new gaskets on the muffler inlet pipes at the exhaust manifold flange.
- Position the cylinder head to the block, and install the head bolts, each in its original position. On all engines on which the exhaust manifold has been removed from the head to facilitate removal, it is necessary to properly guide the exhaust manifold studs into the muffler inlet pipe flange when installing the head.
- Following the cylinder head tightening sequence. Tighten the cylinder head bolts in three stages. First, tighten the bolts to 50 ft. lbs. (68 Nm), then to 60 ft. lbs. (81 Nm), and finally to 70 ft. lbs. (95 Nm). When complete, tighten the exhaust manifold-to-cylinder head attaching bolts.
- Tighten the nuts on the exhaust manifold studs at the muffler inlet flanges to 18 ft. lbs. (24 Nm).
- Clean and inspect the pushrods one at a time. Clean the oil passage within each pushrod with a suitable solvent and blow the passage out with compressed air. Check the ends of the pushrods for nicks, grooves, roughness, or excessive wear. Visually inspect the pushrods for straightness, and replace any bent ones. Do not attempt to straighten pushrods.
- Install the pushrods in their original positions. Apply Lubriplate® or a similar product to the valve stem tips and to the pushrod guides in the cylinder head.
On 6.4L and 7.0L engines, the intake manifold and rocker arm and shaft assemblies must now be installed. When tightening down the rocker arm shaft assembly, check the following;
The oil holes face downward.
- Tighten the rocker arms bolts front to rear, two turns at a time, to avoid bending any pushrods.
- On all engines except the 6.4L and 7.0L, apply white lithium grease to the fulcrum seats and sockets. Turn the rocker arms to their proper positions and tighten the nuts or mounting bolts enough to hold the rocker arms in position. Make sure that the lower ends of the pushrods have remained properly seated in the valve lifters.
- On all engines except the 6.4L and 7.0L, perform a preliminary valve lash adjustment. See Engine Electrical
- Position a new valve cover gasket, and install. Follow the gasket manufacture's instructions when installing. Tighten the bolts evenly to 10-23 ft. lbs. (10-18 Nm)
- Install the intake manifold and carburetor or CFI unit.
- Adjust all drive belts which were removed.
- Refill the cooling system.
- Connect the battery ground cable at the cylinder head (if applicable).
- Install the spark plugs and connect the spark plug wires.
- Check all fluid levels. Start the engine and check for leaks. Bleed the cooling system if needed.
- With the engine running, check and adjust the carburetor idle speed and mixture.
- With the engine running, listen for abnormal valve noises or irregular idle. Road test the vehicle for proper operation.
See Figure 8
- Remove the cylinder head(s) from the engine. Place the head(s) on a workbench and remove the manifolds, if still connected. Remove all the rocker arm retaining parts, keeping the parts in order.
- Turn the cylinder head over so that the mounting surface is facing up and support it evenly on wood blocks.
- Use a gasket scraper and remove all of the old gasket material stuck to the head mounting surface. Use a wire brush to clean away the carbon on the valve and head combustion chambers.
- Number the valve heads with a permanent felt-tip marker for cylinder location.
- Use an electric drill and rotary wire brush to clean the intake and exhaust valve ports, combustion chamber and valve seats. In some cases, the carbon will need to be chipped away. Use a blunt pointed drift for carbon chipping. Be careful around the valve seat areas.
When using a wire brush to clean carbon on the valve ports, valves etc., be sure that the deposits are actually removed, rather than burnished.
- Wash and clean all valve springs, keepers, retaining caps etc., in solvent.
- Clean the head with a brush and some solvent. Wipe dry.
- Check the head for cracks. Cracks in the cylinder head usually start around an exhaust valve seat because it is the hottest part of the combustion chamber. If a crack is suspected but cannot be detected visually, have the area checked with dye penetrant or other method by the machine shop.
See Figure 9
Resurfacing should only be performed by a reputable machine shop. To determine whether resurfacing is necessary, perform the following.
Place a straightedge across the gasket surface of the cylinder head. Using a feeler gauge, determine the clearance at the center of the straightedge. If warpage exceeds 0.003 in. (0.08mm) in a 6 in. (152mm) span, or 0.006 in. (0.152mm) over the total length, the cylinder head must be resurfaced.
If warpage exceeds the manufacturer's maximum tolerance for material removal, the cylinder head must be replaced.
When milling the cylinder heads of V-type engines, the intake manifold mounting position is altered, and must be corrected by milling the manifold flange a proportionate amount. Do not plane or grind more than 0.010 in. (0.25mm) from the original cylinder head gasket surface. This service should be performed by a machine shop.