Disassembly and Assembly

DISASSEMBLY
1. Remove rocker arm seat retaining bolts, rocker arm seats and rocker arms.
2. Remove exhaust manifolds if required, and spark plugs.
3. Clean carbon out of cylinder head combustion chambers before removing valves.
4. Compress valve spring using Valve Spring Compressor 303-163 (T81P-6513-A). Remove valve spring retainer keys and release valve springs.








5. Remove valve spring retainer, valve stem seal and valve. Discard valve stem seals and identify all valve parts from the disassembled cylinder and note whether they are intake or exhaust.
6. Clean, inspect and service cylinder head as required or prepare to transfer all usable parts to a new cylinder head.

ASSEMBLY
All valves, valve stem seals and valve guides are to be lubricated with Super Premium SAE 5W30 Motor Oil XO-5W30-QSP or equivalent meeting Ford specification WSS-M2C153-G. Apply Multi-Purpose Grease DOAZ-19584-AA or equivalent meeting Ford specification ESB-M1C93-B and ESR-M1C159-A to valve tips before installation.
1. Install each valve in port from which it was removed or to which it was fitted.
2. Install exhaust valve stem seal. Make sure valve stem seal is bottomed on guide.

NOTE: Due to different leakage rates between intake and exhaust valve stems, valve stem seals must not be interchanged.

3. Install intake valve stem seal. Valve stem seal must be bottomed on guide.
4. Install lower valve spring retainer.
5. Install valve spring over valve and then install upper valve spring retainer. Compress valve spring and install valve spring retainer keys.
6. Measure assembled height of valve spring from top of lower valve spring retainer to underside of upper valve spring retainer with dividers. Check dividers against a scale. If assembled height is greater than specification, install necessary 0.79 mm (0.030 inch) thick spacer(s) between cylinder head spring pad and lower valve spring retainer to bring assembled height to recommended specification.

CAUTION: Do not install the spacers unless necessary. Use of spacers in excess of recommendations will result in over-stressing valve springs and overloading camshaft lobes which could lead to valve spring breakage and/or worn camshaft lobes.

7. Position rocker arms and rocker arm seats on cylinder heads and install rocker arm seat retaining bolts.

CAUTION: Do not tighten bolts. The bolts must be loose enough to allow rocker arm to be rotated to side.

8. Install exhaust manifold, if removed, and spark plugs.