Valve Spring: Service and Repair

REMOVAL
CYLINDER HEAD OFF





1. With the cylinder head on a bench, position Special Tool C-3422-D with 8464 Adapter on the valve and spring retainer (Fig. 35).
2. Compress the spring only enough to remove the valve retainer locks.
3. Slowly release the spring tension and remove the valve spring and retainer.
4. For removal of the valve stem seal.

CYLINDER HEAD ON
1. Disconnect negative cable from battery.
2. Remove spark plug wires and all spark plugs.
3. Remove cylinder head cover(s).
4. Remove rocker arms and shaft.
5. Rotate engine until the piston in the cylinder bore requiring spring removal is at TDC.





6. Install Special Tool 8453 to the cylinder head (Fig. 36). Tighten the attaching bolts to 23 Nm (200 in. lbs.).
7. Install a spark plug adapter in the spark plug hole. Connect air hose that can supply 620.5 - 689 kPa (90 - 100 psi) of air pressure to adapter. This is to hold valves in place while servicing components.
8. Locate the forcing screw and spring retainer adapter assembly over the spring requiring removal (Fig. 36).
9. Slowly turn the forcing screw clockwise (compressing the valve spring) until the valve keepers can be removed.
10. Turn forcing screw counterclockwise to relieve spring tension. Remove retainer and valve spring.
11. Repeat procedure for each cylinder requiring valve spring removal.

INSPECTION





Whenever valves have been removed for inspection, reconditioning or replacement, valve springs should be tested (Fig. 37). As an example; the compression length of a spring to be tested is 38.00 mm (1.496 inch). Turn the table of Tool C-647 until surface is in line with the 38.00 mm (1.496 inch) mark on the threaded stud and the zero mark on the front. Place spring over stud on the table and lift compressing lever to set tone device. Pull on torque wrench until ping is heard. Take reading on torque wrench at this instant. Multiply this reading by two. This will give the spring load at test length. Fractional measurements are indicated on the table for finer adjustments. Refer to Engine Specifications to obtain specified height and allowable tensions. Replace any springs that do not meet specifications.

INSTALLATION
CYLINDER HEAD OFF
1. If removed, install a new valve stem seal.
2. Position valve spring and retainer on spring seat.
3. Using Special Tool C-3422-C with 8464 Adapter (Fig. 35), compress the spring only enough to install the valve retainer locks.
4. Slowly release the spring tension. Ensure the retainer locks are seated properly.

CYLINDER HEAD ON
1. The intake valve stem seals should be pushed firmly and squarely over the valve guide using the valve stem as guide. Do Not Force seal against top of guide. When installing the valve retainer locks, compress the spring only enough to install the locks.

CAUTION: Do not pinch seal between retainer and top of valve guide.

2. Follow the same procedure on the remaining 5 cylinders using the firing sequence 1-2-3-4-5-6. Make sure piston in cylinder is at TDC on the valve spring that is being covered.
3. Remove spark plug adapter tool.
4. Install rocker arms and shaft assembly.
5. Install cylinder head covers.
6. Install spark plugs and connect wires.
7. Connect negative cable to battery.