Disassembly
Rinse the gearbox and install it on the stand. Drain the oil and remove the bottom cover with gasket.
Remove the clutch release fork, and from the guide sleeve of the front cover of the gearbox - the clutch assembly with the bearing and the connecting spring.
Remove the clutch housing with gasket and the front cover of the gearbox along with the oil seal and spring washer (pic. 3-15).
Pic. 3-15. Interior view of the clutch housing. Black arrows indicate the nuts securing the clutch housing to the gearbox; the white arrow indicates the hole in the front cover to drain the oil from the gearbox housing so that the clutch discs do not get oiled.
Unscrew the reversing light switch, being careful not to deform its housing.
Turn out a bolt of fastening of a plug of switching of III and IV transfers. Install clamp 41.7816.4068 on the input shaft or simultaneously engage two gears. This will prevent rotation of the input, output and intermediate shafts and allow subsequent disassembly operations.
Note. Since 1997, the design of the following parts has changed at the rear end of the output shaft of the gearbox:
- instead of metal centering ring 26 (pic. 3-31) and a retaining ring, a rubber centering sleeve is installed;
- instead of a seal 25 with a spring 24, a seal without a spring is installed;
- lock washer 22 is replaced by a spring washer;
- nut 23 is installed on the UG-9 or UG-10 sealant.
Remove the retaining ring from the end of the output shaft of the gearbox (pic. 3-16).
After unbending the lock washer, loosen the nut a few turns to move the centering ring of the elastic coupling, and tighten the nut again. Using A.40006/1 ejector with A.40005/4 puller, remove from the end of the secondary shaft the centering ring of the flexible coupling of the cardan shaft (pic. 3-17).
Remove the seal of the centering ring of the elastic coupling with the spring from the end of the secondary shaft, unscrew the nut and remove the flange of the elastic coupling with a puller A.40005/3/9B/9C (pic. 3-18).
Pic. 3-18. Removing the flexible coupling flange with a puller А.40005/3/9В/9С:
1 - flange of an elastic coupling; 2 - puller А.40005/3; 3 - stripper A.40005/3; 4 - bolts for fastening the device to the flange.
Before removing the rear cover, place the gear lever in neutral position, unscrew the nuts securing the gear selector mechanism and remove the gear lever (pic. 3-19) complete with selection mechanism. One of the cover fastening nuts is unscrewed from the inside of the gearbox housing with the bottom cover removed. When removing the rear cover, it must be fed not only backwards, but also rotated to prevent it from touching the reverse gear and V gears.
After removal from the secondary shaft of the inner ring of the rear bearing 43 (rice. 3-12) and spacer sleeve 44 of the bearing, loosen the bolts securing the cover 5 (pic. 3-20) and unscrew bolts 2 and 4 fastening the gear unit and the fork for engaging the V gear and reverse gear. Remove oil deflector 45 rice. 3-12), and then sleeve 1 (pic. 3-21) fifth gear and remove rod 1 (pic. 3-22) from the fork 2. At the same time, the distance sleeve 3 is removed from the rod. Then remove the gear unit 4 from the spline of the intermediate shaft.
Pic. 3-20. Unscrewing the bolts of the gear unit and the fork for engaging the V gear and reverse gear:
1 - intermediate reverse gear; 2 - a bolt of fastening of the gear block; 3 - plug stem; 4 - fork fastening bolt; 5 - clamp cover.
Pic. 3-22. Removing the fork rod of the V gear and reverse gear:
1 - fork rod for engaging V gear and reverse gear; 2 - fork for switching on V gear and reverse gear; 3 - remote bushing; 4 - gear block.
Remove intermediate gear 1 at the same time (pic. 3-23) reverse gear from the axle, gear 3 complete with clutch and fork 4 from the secondary shaft.
Pic. 3-23. Removing the reverse gear, V gear assembly with synchronizer and fork:
1 - intermediate reverse gear; 2 - 5th gear engagement clutch; 3 - gear V gear and reverse; 4 - fork.
With the help of curly mandrels (screwdriver type) remove the hub 4 from the key (pic. 3-24) synchronizer V transmission and driven gear 2 reverse.
Pic. 3-24. Removing the reverse driven gear and the 5th gear synchronizer clutch hub:
1 - intermediate shaft; 2 - reverse driven gear; 3 - axis of the intermediate reverse gear; 4 - hub of the synchronizer clutch of the V transmission; 5 - secondary shaft; 6 - a rod of a fork of inclusion of I and II transfers; 7 - rod of the fork of inclusion of III and IV gears.
With the help of curly mandrels (screwdriver type) and rod drifts, remove the front and rear bearings of the intermediate shaft from the gearbox housing. On the inner rings of a double-row bearing, put marks on which these rings should be installed in their original places in the outer ring of the bearing.
Remove the intermediate shaft from the gearbox housing by tilting it as shown in fig. 3-25.
Remove from the gearbox housing one by one the rods of the shift forks of I, II, III and IV gears, having previously unscrewed the bolts of the forks. When pulling out the rods, simultaneously remove the three blocking crackers 6 (pic. 3-26). Remove lock plate (pic. 3-27) output shaft intermediate bearing. Loosen the reverse idler gear axle nut and remove it.
Pic. 3-26. Gear shift drive:
1 - fork of inclusion of III and IV gears; 2 - a rod of a fork of inclusion of I and II transfers; 3 - rod of the fork of inclusion of III and IV gears; 4 - fork of inclusion of I and II transfers; 5 - rod of the fork for engaging the V gear and reverse gear; 6 - block crackers; 7 - cover of clamps; 8 - spring clamps; 9 - a ball of clamps; 10 - fork for switching on V gear and reverse gear; 11 - head of the fork of the V gear and reverse gear; 12 - a block of gears of V gear and reverse; 13 - axis of the intermediate reverse gear; 14 - intermediate reverse gear; 15 - washer of the guide plate; 16 - guide plate; 17 - gear lever housing; 18 - ball bearing; 19 - spherical washer; 20 - spring; 21 - thrust washer; 22 - retaining ring.
With mandrels (screwdriver type) remove the input shaft along with the bearing and synchronizer ring (pic. 3-28) and remove the needle bearing from the front end of the output shaft.
Knock out the secondary shaft from the intermediate bearing, remove the intermediate bearing and, tilting, as shown in fig. 3-29, remove the output shaft assembly with gears, clutches and synchronizer rings from the crankcase. Remove the 3rd and 4th gear synchronizer coupling from the shaft.
Disassemble the input shaft (pic. 3-30), For what:
- remove the retaining ring 7, blocking ring 6 and synchronizer spring 5;
- install the shaft on the press and, compressing the spring washer 2 with the mandrel 41.7816.4069, remove the retaining ring 1, and then the spring washer and bearing 3.
Pic. 3-30. Main shaft details:
1 - retaining ring; 2 - spring washer; 3 - bearing; 4 - input shaft; 5 - synchronizer spring; 6 - synchronizer blocking ring; 7 - retaining ring; 8 - bearing.
Disassemble the output shaft (pic. 3-31):
- remove from the rear side of the shaft the gear 11 of the first gear with the sleeve 12, the hub 3 with the sliding clutch 4 for switching I and II gears, the gear 10 of the second gear together with the blocking ring 5 of the synchronizer;
- install the secondary shaft with mandrel 41.7816.4069 on the press (pic. 3-32), place support half rings 3 under the gear of the III gear and, pressing the mandrel on the spring washer, remove the retaining ring 2, then the spring washer 4, the hub of the sliding clutch of the III and IV gears and the gear of the III gear.
Pic. 3-31. Output shaft details:
1 - retaining ring; 2 - spring washer; 3 - synchronizer hub; 4 - synchronizer clutch; 5 - blocking ring; 6 - synchronizer spring; 7 - washer; 8 - gear of the III gear; 9 - secondary shaft; 10 - gear wheel of the 2nd gear; 11 - gear 1st gear; 12 - gear bushing; 13 - bearing; 14 - key; 15 - reverse gear; 16 - gear V gear; 17 - oil deflector washer; 18 - spacer sleeve; 19 - rear bearing of the secondary shaft; 20 - stuffing box; 21 - flange of an elastic coupling; 22 - lock washer; 23 - nut; 24 - spring seal; 25 - sealant; 26 - centering ring.
Pic. 3-32. Installation on the secondary shaft of the retaining ring:
1 - mandrel 41.7816.4069; 2 - retaining ring; 3 - support half ring; 4 - spring washer; 5 - press rod.
If necessary, disassemble the lever and the gear selection mechanism, for which:
- remove protective cover 10 (pic. 3-33), retaining and thrust rings 6 and 7, spring 5 and spherical washer 4 from the gear lever;
- visually mark the location of the parts relative to the risk A (pic. 3-34), printed on the guide plate, so that when assembling, connect the parts in the same position;
- having unscrewed the nuts from the fastening bolts, separate the parts of the gear selection mechanism and remove the lever 9, its ball joint 4 and rubber sealing rings 15.
Pic. 3-33. Details of the lever and gear selection mechanism:
1 - gear lever; 2 - gasket; 3 - ball bearing; 4 - spherical washer; 5 - spring; 6 - ring; 7 - retaining ring; 8 - flange; 9 - cuff; 10 - protective cover; 11 - handle; 12 - lever rod; 13 - thrust pad; 14 - elastic sleeve; 15 - remote bushing; 16 - locking sleeve; 17 - gear lever housing; 18 - sealing ring; 19- washer of the guide plate; 20 - guide bar; 21 - spring; 22 - guide plate; 23 - reverse blocking plate.
Pic. 3-34. Gear selection mechanism:
1 - washer of the guide plate; 2 - guide plate; 3 - gear lever housing; 4 - ball bearing; 5 - spherical washer; 6 - spring; 7, 8 - retaining rings; 9 - gear lever; 10 - protective cover; 11 - flange; 12 - reverse blocking plate; 13 - spring; 14 - guide bar; 15 - sealing ring; A is risk.
Assembly
Assemble the gearbox in the reverse order of disassembly. In doing so, keep in mind that:
- the axis of the intermediate reverse gear is attached before the shafts are installed in the gearbox housing with a torque of 78 Nm (7.8 kgf·m);
- before installing the 5th gear and reverse fork rod into the crankcase, install a distance sleeve on it;
- the inner ring of the bearing is pressed onto the gear unit of the 5th gear and reverse, and the outer ring is pressed into the socket of the rear cover;
- the secondary shaft rear bearing is pressed onto the shaft to facilitate installation of the rear cover;
- intermediate gear 1 (pic. 3-23) reverse gear, gear 3 and fork 4 are installed at the same time;
- when assembling the gear lever, coat the ball head or ball bearing sphere with LSTs-15 or Litol-24 grease;
- tighten the gear block mounting bolt to a torque of 78 Nm (7.8 kgf·m);
- when installing the clutch housing with the front cover of the gearbox, the hole in the front cover must be located as shown in fig. 3-15;
- before installation, coat the working surface of the seals with Litol-24 grease;
- when installing oil seals and bearings, use mandrels 41.7853.4028, 41.7853.4032, 41.7853.4039.