The spring fits around the spigot on the outer end of the clutch piston. A 6mm ball is fitted inside the central hole in the piston to provide and abutment for the clutch push rod. A small quantity of high melting point grease should be introduced into the hole before refitting the cover to the engine.
For attention to these components remove the large domed nut next to the oil pressure switch on the outside of the timing cover, (24mm spanner on early machines, 22mm on later models). Remove the threaded sleeve and take out the spring and plunger.
The pressure relief valve seat is a hard steel washer pressed into the bore of the hole. This part does not normally need attention, except to very that it has not become misplaced during dismantling.
NOTE: When reassembling check that all the oil ways are clear, for example by gently blowing through with an air line.
Check that the valve seat is in place. Assemble the domed nut and dowty washer to the threaded adjuster. Fit the plunger and spring in the hole, followed by the threaded sleeve assembly. When the engine is reassembled the valve may be set to the correct pressure (3.5 bars, 50 p.s.i) by turning the threaded sleeve inwards to increase the pressure or outwards to reduce it. This task should be carried out when the engine oil is at running temperature. The most convenient way to measure the oil pressure is to attach a gauge to the union provided at the top of the of the timing cover (thread M10x1) A suitable gauge is available as Service Tool No. 8232).
