Refit the camshaft and top bevel housing to the head, using a smear of jointing compound on the triangular face joint. See that both faces are clean and flat, but do not use any joint washer between the metal faces. Tighten the three nuts carefully. Refit the square cover with any packing shims used originally and tighten the four screws. Finally clean face joints of bevel bush housing and bevel housing and obtain new joint washers (K120), slipping these in place over the two studs. Note that the same number as were originally fitted must be used. It is also most important only to use genuine packings as supplied by us as these are of the correct thickness. Use jointing compound on the metal faces.
Having tightened up the nuts evenly, check the fit of the bevel gears. These must mesh the full width of the teeth and must turn perfectly freely with no trace of backlash. Backlash, if any, may be taken out by reduction in the number of joint packings fitted between the bush housing and the bevel housing. It should also be noted that the fitting of additional shims behind the square cover on the left of the head allows the camshaft to move further over to the left and would increase the backlash between the bevels. It is not usually necessary to vary the number of shims or to fit one if none were used during initial assembly at works.
The final assembly of valves and springs, etc., and the re-setting of the tappet clearances is dealt with in the sections covering these respective jobs.