CYLINDER HEAD-E.6 To Dismantle the Rocker Shaft Assembly ~ I 1. Remove the retaining circlips from each end of the rocker shaft. 2. Withdraw the rocker levers, springs and support brackets from the rocker shaft. 3. Unscrew the oil feed pipe from the banjo and re- move the banjo. (When refitting this feed pipe it should be noted that the end of the pipe locates the banjo position on the shaft). Examine the rocker bushes and shaft for wear. The rocker levers should be an easy fit on the rocker shaft without excessive side play. New rocker levers are supplied complete with bush fitted and reamed to size. E17 NOTE:
When fitting new bushes ensure that the oil feed holes are in alignment before pressing home; and when pressed fully home that the holes coincide. (Refer to Fig. Ј,17). VALVE SEAT INSERTS Valve seat inserts are not fitted to production engines, but may be fitted in service. When fitting inserts ensure that only genuine Perkins parts are used. In order to fit these inserts proceed as follows: 1. Fit new valve guides as described on Page E.4. 2. Using the new valve guide bore as a pilot, machine the insert recess in the cylinder head face to the dimensions shown in Fig. E.15. 3. Remove all machining swarf and thoroughly clean the insert recess (removing any burrs which may be present). 4.
Using the valve guide bore as a pilot once again press the insert home with the inserting tool, this tool is shown fully dimensioned in Fig. E.16. NOTE: The insert must not under any circum- stances be hammered in, neither should any lubri- cation be used. 5. Visually inspect to ensure that the insert has been pressed fully home, i.e. is flush with the bottom of the recess. 6. Recut the valve seat at an included angle of 90' (which will give the normal 45' seat) until the valve head depth reaches the minimum limit which is given on Page B.8. Lightly lap the valve to its new seat. To Re-Assemble the Rocker Shaft Assembly 1. Refit the oil feed banjo and locate with the feed pipe. 2.
Refit the rocker levers, springs and support brackets in the opposite order to which they were removed. Lightly oil the components during re- assembly and ensure that each rocker lever does not bind on the shaft. The assembly should now be as shown in Fig. E.18. PUSH RODS Check the push rods for straightness, if any are bent then fit new replacements. To Refit the Valves Lightly oil the valve stems to provide the initial lubrica- tion. Replace valves, springs, spring plates, washers, collars and collets, taking care that the numbers on the valves correspond to the numbers stamped adjacent to the valve seat (see Fig. E.6). E18