2. Remove the reversing light switch and the speedometer driven gear.
3. Remove the clutch housing from the gearbox housing.
4. Remove the gearshift housing assembly using a plastic hammer, after removing the six bolts.
5. Remove the crankcase extension using a plastic hammer, after unscrewing ten bolts.
6. Remove the front bearing housing using a plastic hammer, after unscrewing the eight bolts.
7. Using round-nose pliers, remove the retaining rings.
8. Remove the side cover using a plastic hammer, after unscrewing the four bolts.
9. Disconnect the intermediate plate from the gearbox housing
a) Using a hammer and a punch, carefully detach the gearbox housing.
c) Separate the gearbox housing from the intermediate plate.
10. Remove the magnet from the intermediate plate.
11. Clamp the intermediate plate in a vice using the two clutch housing mounting bolts, flat washers and suitable nuts.
Warning: Install flat washers upside down compared to their normal position. Increase or decrease the number of flat washers to achieve a position where the end of the bolt tip and the end surface of the nut are flush with each other.
12. Unscrew the threaded plugs, remove the springs and retaining balls.
a) Using the tool, unscrew the threaded plugs.
b) Using a magnetic finger, remove the springs and retaining balls.
13. Remove the mounting bolts.
14. Using two screwdrivers and a hammer, remove the seven retaining rings.
15. Remove the shift fork rod No.1.
a) Remove the shift fork rod No.1 from the intermediate plate.
b) Using a magnetic finger, remove the spring and balls.
16. Using a special tool, remove the split pin.
17. Remove the shift fork rod No.2, the shift fork and the rod head.
a) Remove the shift fork rod No.2 from the intermediate plate.
b) Remove shift fork No.2 and the rod head.
c) Using a magnetic finger, remove the pins from the intermediate plate.
Gearbox. Type R452 and R453.
1 - Reverse light switch,
2 - Switch mechanism housing,
3 - Oil receiver,
4 - Extension housing,
5 - Speedometer drive driven gear,
6 - Intermediate plate,
7 - Side cover,
8 - Box housing,
9 - Front bearing housing,
10 - Clutch housing,
11 - Gear shift fork rod No.1,
12 - Gear shift fork No.2,
13 - Gear shift fork rod No.2,
14 - Gear shift fork No.1,
15 - Reverse gear shift linkage bracket,
16 - Reverse gear engagement linkage,
17 - Gear shift fork No.3,
18 - Reverse gear engagement fork,
19 - Head of the reverse gear engagement rod,
20 - Gear shift fork rod No.4,
21 - Gear shift fork rod No.3,
22 - External gear shift lever,
23 - Gear selection and shift shaft,
24 - Cover,
25 - Seal,
26 - Spring,
27 - Gear selection and engagement lever,
28 - Saddle,
29 - Spring,
30 - Inner gear selector lever,
31 - Seal,
32 - External gear selector lever,
33 - Reverse gear engagement locking pin and spring.
18. Remove shift fork rod No.3 and shift fork No.1.
a) Remove the shift fork rod No.3 from the intermediate plate.
b) Remove gear shift fork No.1.
c) Using a magnetic finger, remove the pins and retaining balls from the intermediate plate.
19. Remove the reverse gear engagement rod head and the locking ball.
20. Remove shift fork rod No.4 and shift fork No.3.
a) Remove the shift fork rod No.4 from the intermediate plate.
b) Remove gear shift fork No.3.
21. Remove the reverse gear selector lever from the bracket.
22. Unscrew the two bolts and remove the reverse gear shift linkage bracket.
23. Using a puller, remove the secondary shaft rear bearing.
24. Remove the speedometer drive pinion and ball.
R452 and R453 gearbox components.
1 - Primary shaft,
2, 10, 14, 23, 26 - Synchronizer ring,
3 - Speedometer drive pinion,
4 - Rear bearing housing,
5 - Intermediate shaft,
6 - Reverse intermediate gear and shaft,
7 - Thrust washer,
8 - Fifth gear intermediate gear,
9 - Hub coupling No.3,
11 - Fifth gear synchronizer hub,
12 - Clutch hub No.2,
13 - Hub coupling No.3,
15 - Third gear pinion,
16, 20, 28 - Needle bearing,
17 - Secondary shaft,
18 - Fifth gear pinion,
19 - Thrust washer,
21 - Spacer sleeve,
22 - First gear pinion,
24 - Clutch hub No.1,
25 - Reverse gear,
27 - Second gear pinion.
25. Measure the axial clearance of the fifth gear intermediate gear.
Using a set of feeler gauges, measure the axial clearance of the fifth gear intermediate gear.
- Nominal clearance - 0.1-0.35 mm
- Maximum gap - 0.4 mm
26. Remove the fifth gear synchronizer hub, synchronizer ring, needle bearings and fifth gear intermediate gear with hub coupling No.3.
a) Engage the gears.
b) Using a hammer and chisel, chisel the nut.
c) Remove the lock nut.
d) Disengage the gears.
d) Using a puller, remove the fifth gear synchronizer hub.
e) Remove the fifth gear intermediate gear and hub coupling No.3.
27. Remove the thrust washer and ball.
28. Unscrew the four bolts and remove the rear bearing cover.
29. Remove the reverse intermediate gear and shaft.
30. Using round-nose pliers, remove the bearing retaining ring.
31. Remove the secondary shaft, intermediate shaft and primary shaft as one assembly from the intermediate plate.
a) Remove the secondary shaft, intermediate shaft and primary shaft from the intermediate plate as follows: pulling the intermediate shaft towards you and hitting the intermediate plate with a plastic hammer as shown in the figure.
b) Remove the primary shaft with the 13-roller needle roller bearing from the secondary shaft.
32. Using a punch and hammer, knock the intermediate shaft bearing out of the plate.
33. Measure the axial clearance of each gear.
First gear pinion:
- Nominal clearance - 0.10-0.45 mm
- Maximum gap - 0.50 mm
Second and third gears:
- Nominal clearance - 0.10-0.25 mm
- Maximum gap - 0.30 mm
34. Remove the fifth gear pinion, center bearing and first gear pinion.
a) Using a press, remove the fifth gear pinion, center bearing, thrust washer and first gear pinion.
b) Remove the synchronizer ring.
c) Remove the pin and needle bearing.
d) Remove the spacer sleeve.
35. Remove hub coupling No.1 and second gear assembly.
a) Using two screwdrivers and a hammer, remove the retaining ring.
b) Using a press, remove the hub coupling No.1, the synchronizer ring and the second gear.
c) Remove the needle bearing.
36. Remove hub coupling No.2 and third gear assembly.
a) Using round-nose pliers, remove the retaining ring.
b) Using a press, remove the hub coupling No.2, the synchronizer ring and the third gear.
c) Remove the needle bearing.
37. Remove the outer and inner gear selector lever.
a) Remove the locking pin and unscrew the nut.
b) Remove the outer and inner gear selector lever.
38. Remove the locking pin, outer gear shift lever and boot.
39. Remove the gear selection and engagement shaft.
a) Using a special tool, remove the split pin.
b) Remove the gear selection and engagement shaft.
c) Remove the gear selection and engagement lever, two springs and seat.
40. Remove the reverse gear locking pin and spring.
a) Using a special tool and a hammer, remove the split pin.
b) Remove the reverse gear locking pin and spring.
