MG MGA Twin Cam Workshop Manual page 143

Fig. H.5 Using service tool 18G285 to remove the bevel pinion
A. SETTING THE PINION POSITION
1. Fit the bearing outer races to the gear carrier, using the special pinion race replacing tool.
2. Smooth off the pinion head with an oil-stone but do not erase any markings that may be
etched on the pinion head.
3. Assemble the pinion and rear bearing with a washer of known thickness behind the pinion
head,
4. Position the pinion in the gear carrier without the shims, bearing spacer, and oil seal.
5. Fit the inner ring of the front bearing and the universal joint driving flange and tighten the
nut gradually until a bearing preload of 10 to 12 lb. in. (.12 to .14 kg. m.) is obtained.
6. Remove the keep disc from the base of the magnet. Adjust the dial indicator to zero on
the machined step 'B* of the setting block.
7. Clean the pinion head and place the magnet and dial indicator in position (Fig. H.7). Move
the indicator arm until the foot of the gauge rests on the centre of the differential bearing
bore at one side and tighten the knurled locking screw. Obtain the maximum depth
reading and note any variation from the zero setting. Repeat the check in the opposite
bearing bore. Add the two variations together and divide by two to obtain a mean reading
8. Take into consideration any variation in pinion head thickness. This will be shown as an
unbracketed figure etched on the pinion head and will always be minus (-). If no
unbracketed figure is shown the pinion head is of nominal thickness.
Using the mean clock gauge reading obtained and the unbracketed pinion head figure (if
any), the following calculation can be made.
a. If the clock reading is minus add the clock reading to the pinion head marking, the
resulting sum being minus. Reduce the washer thickness by this amount.
143
©2018 morrisgarages.ch