Shift Mechanism and Geartrain
DISASSEMBLYFig. 48:
1. Install suitable bolts and washers in intermediate plate (Fig. 48). Then clamp plate and gear assembly in vise. Use enough washers to prevent bolts from touching. Also be sure vise jaws are clamped on bolt heads.
Fig. 49:
2. Remove countershaft fifth gear retaining snap ring (Fig. 49).
Fig. 50:
3. Remove bolt holding fifth gear shift fork to shift rail (Fig. 50).
Fig. 51:
4. Remove fifth gear blocker ring from countershaft assembly with Puller L-4407 (Fig. 51).
Fig. 52:
5. Remove fifth gear synchro ring (Fig. 52).
Fig. 53:
6. Remove the countershaft fifth gear assembly from countershaft (Fig. 53).
Fig. 54:
7. Remove fifth gear thrust ring from countershaft (Fig. 54).
Fig. 55:
8. Remove fifth gear thrust ring lock ball from countershaft (Fig. 55).
NOTE: There are many lock balls, check balls, interlock balls, and interlock pins used in various places in the transmission. Whenever a pin or ball is removed, it should be identified in such a way that it can be reinstalled in the same location from which it was removed.
9. Remove bolt holding reverse idler gear shaft lock plate to the intermediate plate.
Fig. 56:
10. Remove reverse idler gear shaft and reverse idler gear assembly (Fig. 56).
NOTE: Be sure to retrieve the pin and compression spring from the reverse idler shaft.
Fig. 57:
11. Remove bolts holding output shaft rear bearing retainer to the intermediate plate and remove retainer (Fig. 57).
Fig. 58:
12. Remove bolts holding 1-2 and 3-4 shift forks to the shift rails (Fig. 58) and discard bolts.
Fig. 59:
13. Remove bolts holding reverse shift arm bracket to intermediate plate (Fig. 59).
Fig. 60:
14. Remove snap-ring holding output shaft rear bearing into the intermediate plate (Fig. 60).
15. Remove countershaft rear bearing snap-ring.
Fig. 61:
16. With aid of an assistant, support the mainshaft and countershaft. Tap on the rear of the mainshaft and countershaft with a suitable plastic mallet. This will release the countershaft from the countershaft rear bearing and the mainshaft rear bearing from the intermediate plate. The countershaft will release from the countershaft bearing first and can be removed by moving the countershaft rearward and downward (Fig. 61).
Fig. 62:
17. Remove the mainshaft by moving the mainshaft forward until the mainshaft rear bearing is clear of the intermediate plate and then rotating the mainshaft downward out of the shift forks (Fig. 62).
Fig. 63:
18. Remove the 3-4 shift fork from the 3-4 shift rail (Fig. 63).
19. Remove the snap-ring from near the end of the 1-2 shift rail to allow the removal of the 1-2 shift fork.
Fig. 64:
20. Remove the 1-2 shift fork from the 1-2 and the 3-4 shift rails (Fig. 64).
Fig. 65:
21. Remove threaded plugs from intermediate plate. Then remove lock ball and spring from plug holes with pencil magnet (Fig. 65). Note that the bottom spring is shorter in length than the other two springs.
22. Remove the intermediate plate from the vise, rotate the plate 180°, and reinstall the plate in the vise using the same bolt and washer mounting setup.
CAUTION: The interlock balls and pins are different sizes and shapes. Be sure to correctly identify which position an item is removed from to ensure that it is reinstalled in the same location.
Fig. 66:
23. Remove fifth gear shift rail (Fig. 66).
Fig. 67:
24. Remove fifth gear check ball (Fig. 67) and interlock pin.
Fig. 68:
25. Remove reverse shift head and rail assembly (Fig. 68).
26. Remove snap-ring holding reverse shift rail into intermediate plate.
Fig. 69:
27. Remove reverse shift rail and reverse shift fork and arm assembly from intermediate plate (Fig. 69).
Fig. 70:
28. Remove interlock pin from reverse shift rail (Fig. 70).
Fig. 71:
29. Remove reverse elongated check ball (Fig. 71).
30. Remove snap-ring on 3-4 shift rail.
31. Remove 1-2 shift rail from intermediate plate.
Fig. 72:
32. Remove interlock pin from 1-2 shift rail (Fig. 72).
Fig. 73:
33. Remove 1-2 shift rail elongated check ball from intermediate plate (Fig. 73).
34. Remove 3-4 shift rail from intermediate plate.
ASSEMBLY
Fig. 74:
Refer to (Fig. 74) while assembling and installing the shift rail components. Also verify that all shift rail components are in their neutral position when installing the check balls and interlock pins.
1. Install the 3-4 shift rail into the intermediate plate.
Fig. 75:
2. Install the 1-2 elongated check ball into the intermediate plate (Fig. 75).
Fig. 76:
3. Install the interlock pin into the 1-2 shift rail (Fig. 76).
4. Install the 1-2 shift rail into the intermediate plate.
5. Install snap-ring onto 3-4 shift rail.
Fig. 77:
6. Install the reverse check ball into the intermediate plate (Fig. 77).
Fig. 78:
7. Install the interlock pin into the reverse shift rail (Fig. 78).
Fig. 79:
8. Assemble the reverse arm bracket to the reverse fork (Fig. 79).
Fig. 80:
9. Install reverse shift rail into intermediate plate and position reverse arm bracket to intermediate plate (Fig. 80).
Fig. 81:
10. Install snap-ring onto reverse shift rail (Fig. 81).
11. Install reverse shift head and rail assembly into the intermediate plate.
Fig. 82:
12. Install the fifth gear interlock ball and check ball (Fig. 82).
Fig. 83:
13. Install fifth gear shift rail (Fig. 83).
14. Remove the intermediate plate from the vise, rotate the plate 180°, and reinstall the plate in the vise using the same bolt and washer mounting setup.
15. Install the shift rail detent balls in the intermediate plate.
16. Install the shift rail detent springs in the intermediate plate. Note that the bottom detent spring is shorter than the others.
17. Install the shift rail detent plugs in the intermediate plate.
Fig. 84:
18. Install the 1-2 shift fork onto the 1-2 and 3-4 shift rails (Fig. 84).
19. Install the snap-ring onto the 1-2 shift rail.
Fig. 85:
20. Install the 3-4 shift fork onto the 3-4 shift rail (Fig. 85).
21. Install mainshaft into the intermediate plate by guiding the output shaft through opening in intermediate plate until the shift forks are aligned with the appropriate synchronizer sleeves. The mainshaft rear bearing will be started in the intermediate plate but not fully driven in at this point.
22. While an assistant supports the mainshaft, align rear of countershaft with inner race of countershaft rear bearing.
23. Raise countershaft upward until gears mesh with the mating gears on the mainshaft.
24. Using a suitable rubber mallet, tap on the input shaft and the front of the countershaft equally to install the mainshaft rear bearing into the intermediate plate and the rear of the countershaft into the rear countershaft bearing. It may be necessary to occasionally hold the countershaft into the intermediate plate and tap the countershaft rear bearing onto the countershaft and into the intermediate plate.
25. Install snap-rings onto the rear mainshaft and countershaft bearings.
26. Install the bolts to hold the reverse shift arm bracket to the intermediate plate.
Fig. 86:
27. Install new bolts to hold the shift forks to the shift rails (Fig. 86).
28. Position the mainshaft rear bearing retainer over the output shaft and onto the intermediate plate.
29. Install new bolts to hold the bearing retainer to the intermediate plate.
Fig. 87:
30. Move the reverse shift arm into the reverse gear position. The reverse gear position is with the arm moved away from the intermediate plate (Fig. 87).
31. Install the reverse idler gear assembly into position on the mainshaft and reverse shift arm.
Fig. 88:
32. Install the compression spring and pin into the reverse idler gear shaft (Fig. 88).
Fig. 89:
33. Install the reverse idler shaft through the intermediate plate and reverse idler gear assembly (Fig. 89) until the idler shaft pin contacts the gear assembly. Make sure that the notched cut-out in the idler shaft is to the rear of the transmission.
Fig. 90:
34. Align the pin with the alignment notch in the reverse idler gear assembly (Fig. 90). The alignment notch in the reverse idler gear race/hub is a small relief cut above one of the main longitudinal slots. Be sure that the pin is aligned with the proper slot, the opposite slot has an oil drain hole which the pin will drop into. The assembly will then be locked onto the shaft and will need to be disassembled in order to be removed.
Fig. 91:
35. Depress compression spring and pin in reverse idler gear shaft (Fig. 91).
36. Install the reverse idler gear shaft the remainder of the way through the reverse idler gear assembly.
37. Position the reverse idler gear shaft lock plate onto the intermediate plate.
38. Install a new bolt to hold the idler gear shaft lock plate to the intermediate plate.
Fig. 92:
39. Install the fifth gear thrust ring lock ball to the countershaft (Fig. 92).
Fig. 93:
40. Install the fifth gear thrust ring onto the countershaft and over the lock ball (Fig. 93).
41. Install fifth gear shift fork to the countershaft fifth gear assembly.
42. Install the countershaft fifth gear bearings into the countershaft fifth gear assembly.
43. Position the countershaft fifth gear assembly on the countershaft. Ensure that the fifth gear fork is installed onto the fifth gear shift rail.
44. Install the fifth gear synchro ring.
45. Position the fifth gear blocker ring onto the countershaft.
46. Using a suitable mallet and spacer, tap the fifth gear blocker ring onto the countershaft.
Fig. 94:
47. Install new bolt to hold fifth gear shift fork to the fifth gear shift rail (Fig. 94).
48. Measure countershaft fifth gear thrust clearance.
49. Select a snap-ring so that the thrust clearance is 0.10 - 0.30 mm (0.004 - 0.010 inch).
50. Install snap-ring to hold fifth gear blocker ring onto countershaft.
51. Remove intermediate plate from vise and remove bolts and washers from intermediate.