ZM001DB/ZM001DF gearbox assembly

Assembly of Gearbox ZM001DB/ZM001DF — step-by-step instruction

We examined the gearbox disassembly in the article — «Gearbox disassembly».

Materials used and precautions:

To drive in the split rings and pins, use a copper or steel rod and a hammer; to drive out the pins — a drift punch and a hammer.
To install small items (balls, pins), use a magnetised rod.
Apply a thin layer of transmission oil or grease to the needle bearings and the guide rods of the lock mechanism.
Apply sealant to the thread of the plugs and mounting bolts before screwing them in.
Tighten the mounting bolts to the recommended torque; for multiple bolts, follow the diagonal sequence.
When installing the snap rings, use pliers; the ring must fit tightly against the intermediate case.
Do not fully tighten the shift block mounting bolt before completing the alignment of all elements.

Gearbox assembly

1. Assembly of the gearbox output shaft

1) Assemble the third/fourth synchroniser components as shown in the figure. Install the third gear needle bearing, the third gear, the third/fourth/fifth synchroniser ring and the third/fourth synchroniser components.

Fig. 1. Assembling the third/fourth synchroniser components

2) Assemble the first/second synchroniser components as shown in the figure. Install the second gear needle bearing, the second gear, the first/second synchroniser ring and the first/second synchroniser components. Apply a thin layer of transmission oil to the steel ball to install it on the input shaft. Then install the first gear, the first gear needle bearing, the first gear bushing, the bearing and the fifth gear. Install the fifth gear snap ring.

Fig. 2. Assembling the first/second synchroniser components

2. Installation of the output shaft into the intermediate case

1) Install the output shaft into the intermediate case as shown in the figure.

Fig. 3. Installing the output shaft into the intermediate case

2) Install the rear bearing snap ring of the output shaft using pliers.

Fig. 4. Installing the rear bearing snap ring of the output shaft

Note: the snap ring must fit tightly against the intermediate case.

3. Installation of the input shaft into the output shaft

1) Install the input shaft bearing onto the input shaft and install the input shaft snap ring using pliers.

Fig. 5. Installing the input shaft bearing and snap ring

2) Apply grease to the needle bearing, install it into the input shaft and then install the third/fourth/fifth synchroniser ring.

Fig. 6. Installing the needle bearing and synchroniser ring

3) Screw the input shaft into the output shaft so that the three slots on the synchroniser ring align with the synchroniser key.

Fig. 7. Aligning the synchroniser ring slots with the key

4. Installation of the intermediate shaft into the intermediate case

1) Install the snap ring on the rear bearing of the gearbox intermediate shaft.

Fig. 8. Installing the snap ring on the intermediate shaft rear bearing

2) Install the gearbox intermediate shaft into the intermediate case, secure the intermediate shaft, and then install the intermediate shaft rear bearing.

Fig. 9. Installing the intermediate shaft and rear bearing

5. Installation of the rear bearing retaining plate

Install the rear bearing retaining plate and secure it with the mounting screws. Tighten the screws to the recommended torque.

Fig. 10. Installing the rear bearing retaining plate

6. Installation of the intermediate gear and reverse shaft

1) Install the intermediate gear and the reverse shaft as shown in the figure.

Fig. 11. Installing the intermediate gear and reverse shaft

2) Install the retaining plate and secure it with the mounting bolts. Tighten the bolts to the recommended torque.

Fig. 12. Installing the retaining plate and mounting bolts

7. Installation of the rocker bracket

Install two small pins on the intermediate case, install the reverse rocker bracket and secure it with the mounting bolts. Tighten the bolts to the recommended torque.

Installing the rocker bracket — Fig. 13. Installing the reverse rocker bracket

8. Installation of the detent ball and thrust washer

Install the detent ball and the fifth gear thrust washer.

Installing the detent ball and thrust washer — Fig. 14. Installing the detent ball and fifth gear thrust washer

9. Installation of the intermediate shaft fifth gear

1) Assemble the intermediate shaft fifth gear as shown in the figure.

Fig. 15. Assembling the intermediate shaft fifth gear

2) Apply transmission oil to the needle bearing.

3) Install the intermediate shaft fifth gear with the synchroniser sleeve and needle bearing.

Fig. 16. Installing the fifth gear with synchroniser sleeve

10. Installation of the synchroniser ring and fifth gear connecting gear

1) Install the synchroniser ring on the conical surface of the fifth gear connecting gear.

Installing the synchroniser ring on the connecting gear — Fig. 17. Installing the synchroniser ring on the conical surface

2) Remove the intermediate case from the vice.

3) Place the gearbox strictly vertically as shown in the figure. Install the fifth gear connecting gear and make sure the synchroniser ring slot is aligned with the synchroniser key.

Fig. 18. Installing the fifth gear connecting gear

4) Select one split ring that will minimise the axial clearance.

Fig. 19. Selecting the split ring to minimise axial clearance

5) Install the split ring using a copper rod and a hammer.

11. Measuring the fifth gear axial clearance

Measure the axial clearance of the intermediate shaft fifth gear using a feeler gauge.

Standard value: 0.1–0.3 mm. Maximum value: 0.3 mm.

Fig. 20. Measuring the fifth gear axial clearance

12. Installation of the third/fourth and first/second fork shafts and forks

1) Install the first/second shift fork and the third/fourth shift fork.

Fig. 21. Installing the first/second and third/fourth shift forks

2) Install the third/fourth shift fork shaft into the intermediate case.

3) Screw in and tighten to the recommended torque the third/fourth shift fork mounting bolts.

Fig. 22. Tightening the third/fourth shift fork mounting bolts

13. Installation of the first/second shift fork shaft

1) Apply grease to the lock mechanism guide rod and install it on the first/second shift fork shaft.

Installing the guide rod on the fork shaft — Fig. 23. Installing the lock mechanism guide rod

2) Install the short lock mechanism pin into the intermediate case using a magnetised rod.

3) Install the first/second shift fork shaft into the first/second shift fork and the intermediate case.

Fig. 24. Installing the first/second shift fork shaft

4) Screw in and tighten to the recommended torque the first/second shift fork mounting bolt.

Fig. 25. Tightening the first/second shift fork mounting bolt

14. Installation of the reverse shaft, lever and block

1) Install the reverse block, the reverse lever and two E-clips on the reverse rocker.

Fig. 26. Installing the reverse block and lever

2) Install the rocker on the reverse rocker bracket.

3) Apply grease to the lock mechanism guide rod and install it on the reverse fork shaft.

Fig. 27. Installing the guide rod on the reverse fork shaft

4) Install the lock mechanism pin into the intermediate case using a magnetised rod.

Fig. 28. Installing the lock mechanism pin

5) Install the reverse fork shaft into the reverse lever and the intermediate case.

15. Installation of the fifth/reverse guide block, fork and shaft

1) Install the fifth/reverse guide block on the reverse fork shaft.

Fig. 29. Installing the fifth/reverse guide block

2) Install the fifth gear fork.

3) Install the detent ball into the fifth/reverse guide block using a magnetised rod.

Installing the detent ball into the guide block — Fig. 30. Installing the detent ball

4) Install the fifth gear fork shaft.

5) Install the lock mechanism steel ball into the intermediate case using a magnetised rod.

Fig. 31. Installing the lock mechanism steel ball

6) Install the fifth gear fork shaft into the intermediate case.

7) Drive the elastic cylindrical pin into the fifth gear fork using a drift punch and a hammer.

Driving the pin into the fork — Fig. 32. Driving the pin into the fifth gear fork

8) Install the fifth/reverse fork shaft into the fifth/reverse guide block.

Fig. 33. Installing the fifth/reverse fork shaft

9) Drive the elastic cylindrical pin into the fifth/reverse guide block using a drift punch and a hammer.

Fig. 34. Driving the pin into the guide block

16. Installation of the shift fork shaft split washers

Install the shift fork shaft split washers using a steel rod and a hammer.

Fig. 35. Installing the shift fork shaft split washers

17. Installation of the balls, springs and threaded plugs

1) Install the balls and springs.

Note: install the short spring into the lower part of the intermediate case.

Fig. 36. Installing the balls and springs

2) Apply sealant to the thread of the threaded plugs.

3) Screw in and tighten to the recommended torque the threaded plugs.

18. Installation of the speedometer drive gear

Install the speedometer drive gear.

Fig. 38. Installing the speedometer drive gear

19. Installation of the gearbox case

1) Apply sealant to the gearbox case as shown in the figure.

Fig. 39. Applying sealant to the gearbox case

2) Place the intermediate case strictly vertically as shown in the figure.

Fig. 40. Vertical position of the intermediate case

3) Install the gearbox case onto the intermediate case as shown in the figure.

20. Installation of the front bearing snap ring and front cover

1) Install two snap rings on the input shaft bearing and the front intermediate shaft bearing using pliers.

Fig. 41. Installing the front bearing snap rings

2) Install the front cover.

Note: first apply sealant to the front cover mounting surface.

3) Apply sealant to the thread of the mounting bolts.

4) Screw in and tighten to the recommended torque the mounting bolts.

21. Installation of the rear case, shift shaft and shift block

1) Install the components such as the limit mechanism and oil pipe on the gearbox rear case.

2) Apply a bead of sealant to the gearbox rear case as shown in the figure.

Applying sealant to the rear case — Fig. 43. Applying sealant to the gearbox rear case

3) Install the shift shaft assembly with the shift lever into the gearbox rear case and then engage third gear.

4) Place the shift block through the upper opening of the rear case so that the shift shaft can move through the shift block.

Note: do not fully tighten the mounting bolt at this stage.

5) Insert the shift lever into the slot of the third/fourth fork shaft and then align the fifth/reverse fork shaft with the rear case mounting hole to install it into the gearbox rear case.

6) Screw in and tighten to the recommended torque the gearbox rear case mounting bolts.

7) Screw in and tighten to the recommended torque the shift block mounting bolts.