Having unscrewed the nuts, remove the rear cover of the gearbox housing and the sealing gasket. Remove the adjusting rings from the bearings of the primary and secondary shafts. Remove the cover of the retainers and remove the springs and retainer balls from the sockets. Unscrew the plug and remove the parts of the reverse gear fork retainer. Having unscrewed the bolt and nuts securing the gearbox housing to the clutch housing, remove the housing from the studs.
Having unscrewed the bolts for fastening the forks on the gearshift rods, remove the rods and forks. Take out the axle and remove the intermediate reverse gear. Then take out simultaneously the primary and secondary shafts (pic. 67) from roller bearings of the clutch housing. Remove the differential assembly. Press the bearing outer races out of the clutch housing using tool A.70157.
Pic. 67. Removing the primary and secondary shafts
Loosen the gear selector bolts (pic. 68), take it off. Unscrew the screw securing the gear selector lever and remove it from the rod, and remove the rod from the clutch housing (pic. 69). Unless necessary, the lever and hinge should not be removed from the gear selection rod, since the conical screws of their fastening are installed on the sealant.
Pic. 68. Removing the gear selection mechanism | Pic. 69. Removing the gear selection rod |
If it is necessary to disassemble the secondary shaft, clamp it in a vice with soft metal linings, and then, having unscrewed the nut, press the ball bearing from the shaft with a universal puller. Similarly, the bearing is pressed from the input shaft. Then the driven gears of IV, III, II and I gears and synchronizer parts are removed from the secondary shaft in the order indicated in Fig. 70. The hubs of the synchronizer couplings are removed on a press or with a puller A.40005/1/6. Unless necessary, it is not recommended to press the hubs off the shaft so as not to reduce the tightness in the spline connection; it is also not recommended to press oil seals out of the crankcase if they are not damaged.
Pic. 70. Parts of the output shaft (marked with a sign «*» - only for 5-speed gearbox): 1 - thrust washer; 2 - bearing sleeve; 3 - gear IV gear; 4 - remote bearing ring; 5 - synchronizer blocking ring; 6 - sliding clutch of the synchronizer of III and IV gears; 7 - sliding clutch hub; 8 - gear of the III gear; 9 - retaining ring; 10 - thrust half rings of the secondary shaft; 11 - gear 2nd gear; 12 - sliding clutch of the synchronizer of I and II gears; 13 - retaining ring of the synchronizer hub; 14 - hub of the sliding clutch of the synchronizer of I and II gears; 15 - synchronizer spring; 16 - cracker; 17 - latch; 18 - needle bearing; 19 - gear 1st gear; 20 - thrust washer; 21 - roller cylindrical bearing; 22* - thrust washer; 23* - bearing sleeve; 24 * - gear V gear; 25* - sliding clutch hub; 26 * - sliding clutch of the synchronizer of the 5th gear; 27* - thrust plate; 28 - nut
Disassemble the differential, for which:
- if it is necessary to replace the driven gear of the main gear, unscrew the bolts of its fastening and press the gear 6 (pic. 71) from the box 4 differentials;
- remove the retaining ring from the axis 1 of the satellites and press out the axis. Then semi-axial gears 2 and satellites 5 are removed from the differential box. If necessary, the bearings are pressed from the differential box using stop 67.7853.9582 * and a universal puller, and gear 3 of the speedometer drive.
Pic. 71. Differential assembly
* Stepped cylindrical stop ∅ 30 mm with centering shank ∅ 27.3 mm.
If necessary, the gear selection mechanism is disassembled, for which the axle 4 fastening nut is unscrewed (pic. 72) the gear selector lever and remove the retaining rings 6 from the axis 7 of the reverse fork and from the axis 3 of the locking brackets, remove the reverse fork 10, the gear selection lever assembly with the locking bracket, the axle 4 of the lever and the spring 5.
Pic. 72. Gear selection mechanism assembly: 1 - housing of the gear selection mechanism; 2 - gear selection lever (forward); 3 - guide axis of the locking brackets; 4 - axis of the gear selection lever; 5 - spring; 6 - retaining ring; 7 - axis of the reverse fork; 8 - locking bracket (Bottom part); 9 - lock of the gear selection lever; 10 - reverse fork; 11 - gear selection lever (reversing); 12 - locking bracket (top part)
If necessary, remove the speedometer drive, for which they unscrew the nut of its fastening and, holding the driven gear shaft, remove the speedometer drive.
Work methods, disassembly procedure (assembly) five-speed gearbox are similar to those described above, but before removing the primary and secondary shafts, do the following: after removing the rear cover, lock the input shaft with tool 41.7816.4070 and unscrew the nuts from the primary and secondary shafts, then unscrew the bolt securing the V gear fork on the rod and press it universal puller from the splines of the secondary shaft V gear synchronizer assembly with gear 2 (see fig. 64) and a fork. Then the gear 8 is pressed from the input shaft and the screws securing the thrust plate 9 are unscrewed with an impact drill-screwdriver and the bearing mounting rings are removed.