Stripping The Maincase
1. Remove the eight sideplate nuts and washers from the left hand sideplate and gently tap off the sideplate assembly.
2. Remove the differential unit complete.
3. Remove the right hand sideplate if applicable.
4. Take off the clutch mechanism by removing the three retaining bolts and remove the oil seal. Behind the oil seal is an external circlip which must be removed to allow the clutch shaft to be released form the maincase. This is done by tapping the shaft lightly from the inside of the gearbox, If necessary, warm the maincase around the front bearing area.
5. Slide the oil pump driving gear off the clutch shaft (5 speed only) after removing the wiire retaining rings or circlips and press off the clutch shaft bearing after removing the circlip.
6. Remove the reverse idler gear and bearing from the spigot by taking out the retaining bolt and washer.
7. The reverse spigot is located in the maincase by the retaining bolt. Remove the bolt and heat the maincase to remove the spigot.
8. The pinion shaft assembly can be removed by taking out the six pinion bearing bolts and the bolt ring washer. The pinion shaft, nut, bearing and shims will slide out to the diff side when the maincase is heated.
9. The layshaft bearing will also slide out when the bolt ring washer is removed and the case is heated.
10. Remove all dowels, filler plugs and the filter plate and wash the maincase thoroughly before reassembly.
11. On a 5 Speed gearbox the oil pump is removed by taking out the four pump mounting bolts and sliding the pump out through the sideplate opening.