TIMING CASE AND DRIVE - K.2 Fig. K.2. Checking Timing Gear Backlash. 3. Refit   the   heat   exchanger   support   bracket   and tachometer drive. 4. Refit   the   crankshaft   pulley   ensuring   that   the centre  punch  mark  on  the  pulley  coincides  with the  line  on  the  front  face  of  the  crankshaft  (see Fig. K.1).  Fit the retaining setscrew and washer and  tighten  to  a  torque  setting  of  300  Ibf  ft  (42 kgf m) 410 Nm. 5. Refit  the  power  take-off  shaft  to  the  crankshaft pulley and secure with the four setscrews. 6. Replace  the  dynamo/alternator  and  water  pump driving    belt    over    the    respective    pulleys    and adjust as instructed on Page M.1. Checking the Timing Gear Backlash 1. Remove   the   timing   case   cover   as   detailed   on Page K.1. 2. Check the timing gear backlash as shown in Fig. K.2  using  a  clock  gauge  or  feeler  gauges.    The backlash should be 0.003 in (0,08 mm) minimum. To Remove the Idler Gear and Hub 1. Remove the timing case front cover as previously described in this Section. 2. Slacken and remove the three nuts securing the idler   gear   retaining   plate   to   the   idler   hub   and withdraw the retaining plate from its studs. 3. Remove  the  idler  gear  from  the  hub.    The  hub can   now   be   withdrawn   from   its   location   in   the timing case. Fig. K.3. Idler Gear Hub Location. 1.  Idler Gear Hub. 2.  Oil Passage. 3.  Oil Pressure Rail. 4. Clean and thoroughly examine the gear and hub for wear, cracks, and pitting, etc. NOTE:   -   Replacement   gears   are   supplied with  the  bushes  fitted  and  machined  to  the dimensions given on Page B.8. To Refit the Idler Gear and Hub 1. After   ensuring   that   the   oilways   in   the   hub   are perfectly clean, refit the hub to its location in the timing   case.      The   studs,   on   which   the   hub   is located,  are  positioned  so  that  the  hub  will  fit  in one position only, and the boss at the rear of the hub   locates   in   a   recess   machined   in   the   front face of the cylinder block (see Fig. K.3). 2. Remove the top cover and slacken off the rocker assembly securing nuts. 3. Turn   the    crankshaft    to    T.D.C.    No.    1    and   4 cylinders,  i.e.,  with  the  crankshaft  gear  keyway at the top of its periphery. 4. Refit  the  idler  gear  to  its  hub  ensuring  that  the timing  marks  on  the  crankshaft,  camshaft,  fuel pump   and   idler   gears   are   correctly   aligned   as shown in Fig. K.4. 5. Assemble   the   idler   gear   retaining   plate   to   its studs    and    secure    with    the    three    setscrews tightened  to  a  torque  setting  of  30  Ibf  ft  (4,1  kgf m).