Disassembly
NV4500 - Manual TransmissionDISASSEMBLY
EXTENSION/ADAPTER HOUSING
1. Raise and support vehicle.
2. Remove rear propeller shaft.
3. Support transmission with a transmission jack.
4. Remove engine rear support.
5. Remove transfer case, if equipped.
6. Remove bolts attaching extension/adapter housing to gear case (Fig. 6).
7. Remove extension/adapter housing (Fig. 7). There is one alignment dowel in the gear case and one in the extension/adapter housing.
8. Remove rubber spline seal from end of mainshaft (Fig. 8). The seal is used to prevent lubricant loss during shipping and does not have to be replaced if damaged.
FIFTH GEAR NUT
1. Remove extension/adapter housing.
2. Loosen fifth gear clamp nut clamping screw approximately 1 1/2 turns.
3. Install nut Wrench 6743 on fifth gear nut (Fig. 9)
NOTE: Wrench only fits one way on nut. Make sure wrench is fully engaged in nut slots and is not cocked.
4. Install splined Socket 6993 4X2 Socket 6984 4X4 to retain mainshaft while removing the fifth gear nut.
5. Install breaker bar in socket wrench (Fig. 9)
NOTE: Wedge breaker bar handle against workbench. Purpose of socket wrench and breaker bar is to prevent mainshaft from turning while nut is loosened.
6. Remove fifth gear nut, then remove belleville washer from mainshaft.
FIFTH GEAR
1. Remove roll pins that secure countershaft fifth gear shift fork to shift rail with pin punch (Fig. 10). Drive roll pins are out from the bottom of fork.
2. Remove fifth gear clutch hub and gear snap ring on countershaft (Fig. 11).
3. Remove countershaft fifth gear clutch gear and stop ring.
4. Remove fifth gear shift fork and gear assembly. Remove assembly by tapping fork off rail with plastic mallet.
5. Remove fifth gear shift fork from sleeve.
6. Remove sleeve, struts and strut springs from countershaft fifth gear hub, if necessary.
7. Remove countershaft fifth gear needle bearing assembly (Fig. 12).
8. Remove cone shaped rear bearing thrust washer from end of countershaft (Fig. 13). Note position of washer and washer bore notch for locating pin for assembly reference.
9. Remove and retain thrust washer locating pin from countershaft.
10. Remove mainshaft overdrive fifth gear with Puller Tool Set 6444.
11. Position first Puller Jaw 6459 or 6820 on gear (Fig. 14).
12. Assemble Puller Flange 6444-1 and Puller Rods 6444-3 4X2 or 6444-4 4X4 vehicles (Fig. 15).
13. Slide assembled puller flange and rods onto output shaft. Then seat flange in notch of puller jaw (Fig. 15).
14. Position second puller jaw on gear and in notch of puller flange (Fig. 16).
15. Slide Retaining Collar 6444-8 over puller jaws to hold them in place (Fig. 16).
16. Install Puller and Bolt 6444 on puller rods. Then secure puller to rods with retaining nuts (Fig. 17).
17. Tighten puller bolt to remove gear from shaft splines (Fig. 17).
18. Remove mainshaft rear bearing plate bolts and remove fifth gear plate end play shims and bearing cup (Fig. 18).
FRONT RETAINER
1. Remove and discard front bearing retainer bolts (Fig. 19). Do not reused retainer bolts.
2. Lightly tapping retainer back and forth with plastic mallet. Then rock retainer back and forth by hand to work it out of gear case.
NOTE: Retainer flange extends into transmission case and is a snug fit.
3. Remove front retainer seal by (Fig. 20) collapsing one side of seal then prying it out.
4. To remove front retainer bearing cup, assemble Puller Flange 6444-1 and Puller Rods 6444-4 (Fig. 21).
5. Insert Puller Jaws 6453-1 in puller flange (Fig. 21). Narrow lip of puller jaws will go under bearing cup.
6. Install Disc C-4487-1 into bearing retainer on heavy duty transmissions for Insert 6453-2 to rest upon.
7. Install assembled tools in front retainer (Fig. 22) with puller jaws seated under bearing cup.
8. Place Insert Tool 6453-2 in center of puller jaws, to hold puller jaws in place (Fig. 22).
9. Install Puller 6444 on puller rods (Fig. 23) and install retaining nuts on puller rods.
10. Tighten puller bolt to draw bearing cup out of retainer (Fig. 23).
DRIVE GEAR
1. Remove drive gear (Fig. 24).
2. Remove pilot bearing from drive gear (Fig. 25).
3. Remove tapered bearing from drive gear with Puller Flange 6444-1 and Puller Rods 6444-6 (Fig. 26). Then position first Puller Jaw 6447 on bearing
4. Slide assembled puller flange and rod tools onto input shaft. Then seat flange in notch of puller jaw.
5. Position second Puller Jaw 6447 on gear and in notch of puller flange.
6. Slide Retaining Collar 6444-8 over puller jaws to hold them in place.
7. Install Puller 6444 on puller rods then install retaining nuts.
8. Tighten puller bolt to remove bearing cone from drive gear.
MAINSHAFT AND GEARTRAIN
1. Move 1-2 and 3-4 synchro sleeves into neutral.
2. Remove drive gear thrust bearing from forward end of mainshaft (Fig. 27).
3. Remove fourth gear clutch gear and synchro stop ring from mainshaft (Fig. 28).
4. Roll gear case onto left side (Fig. 29).
5. To remove mainshaft assembly (Fig. 29) lift front end of mainshaft slightly.
NOTE: Handling mainshaft carefully because gears are lose on the mainshaft.
6. Grasp mainshaft rear splines, then turn spline end of mainshaft counterclockwise to rotate shaft and geartrain out of case. Tilt mainshaft outward and removed from case.
REVERSE IDLER AND COUNTERSHAFT
1. Remove countershaft rear bearing plate (Fig. 30).
2. Remove countershaft end play shim and rear bearing cup (Fig. 31).
3. Remove reverse idler shaft (Fig. 32).
4. Rotate countershaft outward and push reverse idler gear away from countershaft and toward front of case (Fig. 33).
5. Remove idler gear (Fig. 34).
6. Keep reverse idler gear bearings and spacer together (Fig. 35). Insert idler shaft through gear and bearings to keep them in place.
7. Remove idler gear thrust washers from gear case. Install washers on idler shaft to keep them together for cleaning and inspection.
8. To remove countershaft rear bearing, assemble Puller Flange 6444-1 and Puller Rods 6444-4 (Fig. 36).
NOTE: Shaft cannot be removed from case until rear bearing has been removed.
9. Position first Puller Jaw 6449 on bearing cone
10. Seat puller flange in notch of puller jaw just installed on bearing cone
11. Install second Puller Jaw 6449 on bearing and in notch of puller flange
12. Slide Retaining Collar 6444-8 over puller jaws to hold them in place
NOTE: Retaining collar has small lip on one end and only fits one way over jaws.
13. Install Puller 6444 on puller rods, then secure puller to rods with retaining nuts
14. Tighten puller bolt to remove bearing from shaft. If bearing is exceptionally tight, tap end of puller bolt with copper mallet to help loosen bearing.
15. Remove bearing puller tools then rotate countershaft out of gear case (Fig. 37).
16. To remove countershaft front bearing, assemble Puller Flange 6444-1 and Puller Bolts 6444-4 (Fig. 38).
17. Position first Puller Jaw 6451 on bearing.
18. Seat puller flange in notch of puller jaw.
19. Install second Puller Jaw 6451 on bearing and in notch of puller flange.
20. Slide Retaining Collar 6444-8 over puller jaws to hold them in place
NOTE: Retaining collar has small lip on one end and only fits one way over jaws.
21. Install puller bridge and bolt assembly 6444 on puller bolts and install retaining nuts
22. Tighten puller bolt to remove bearing from shaft. If bearing is exceptionally tight, tap end of puller bolt with mallet to help loosen bearing.
23. Remove bearing puller tools.
GEAR CASE
1. Remove countershaft front bearing cap with hammer (Fig. 39).
2. Remove countershaft front bearing cup with Remover 6454 and Handle C-4171 (Fig. 40).
3. Remove roll pin that secures shift lug on shift rail in case (Fig. 41). A small pin punch can be modified, by putting a slight bend in it to drive pin completely out of shift rail (Fig. 41).
4. Remove shift lug rail.
MAINSHAFT
NOTE: Gear and synchro components can be installed backwards. Paint or scriber gear and synchro components for installation reference. Then stack geartrain parts in order of removal.
1. Remove drive gear thrust bearing from end of mainshaft, if not previously removed.
2. Remove 3-4 synchro hub, third gear stop ring and third gear as an assembly (Fig. 42).
3. Remove third gear bearing from mainshaft (Fig. 43).
4. Remove third gear bearing spacer (Fig. 44).
5. Remove second gear thrust washer snap ring from mainshaft (Fig. 44).
6. Remove second gear thrust washer (Fig. 45). Note washer notch for locating pin.
7. Remove thrust washer locating pin (Fig. 46) with needle nose pliers.
8. Remove second gear (Fig. 47).
9. Remove second gear bearing (Fig. 48).
10. Remove second gear clutch cone snap ring from mainshaft synchro hub groove (Fig. 49).
11. Remove second gear clutch cone, synchro clutch ring and synchro stop ring (Fig. 50).
12. Remove 1-2 synchro hub snap ring (Fig. 51).
13. Remove 1-2 synchro sleeve, hub, struts and springs as an assembly (Fig. 52). Note tapered side of sleeve also goes toward front. Do not disassemble synchro components unless worn or damaged.
14. Remove first gear synchro stop ring and clutch ring (Fig. 53).
15. Remove first gear clutch cone front snap ring from mainshaft hub (Fig. 54).
16. Remove first gear clutch cone (Fig. 55).
17. Remove first gear clutch gear rear snap ring from mainshaft hub (Fig. 55). Do not remove this snap ring unless mainshaft is to be replaced.
18. To remove mainshaft rear bearing, assemble Puller Flange 6444-1 and Puller Rods 6444-3 for 4X2 or 6444-4 for 4X4 (Fig. 56).
19. Position the first Puller Jaw 6445 on the bearing cone.
20. Seat Puller Flange 6444-1 in notch of first puller jaw.
21. Install the second Puller Jaw 6445 on the bearing cone and puller flange.
22. Install Puller 6444 on the puller rods and secure with nuts.
23. Hold hex portion of Puller 6444 a wrench (Fig. 57) and tighten screw.
24. Remove bearing puller tools and rear mainshaft bearing from output shaft.
25. Remove reverse gear thrust washer (Fig. 58).
26. Remove reverse gear and synchro components as assembly (Fig. 59). Do not disassemble synchro components unless they are damaged. If synchro sleeve or struts require service, mark position of sleeve on hub before removal. Correct sleeve position is important as sleeve can be installed backwards causing shift problems.
27. Remove reverse gear bearing assembly from mainshaft (Fig. 59).
28. Remove reverse gear bearing spacer from mainshaft (Fig. 60).
29. Remove reverse clutch gear snap ring (Fig. 60). Tension of this snap ring is considerable. Heavy duty snap ring pliers will be required to spread the ring far enough to remove it.
30. Remove reverse clutch gear (Fig. 61).
31. Remove first gear from bearing and mainshaft (Fig. 62).
32. Remove first gear bearing from mainshaft (Fig. 63).