Assembly

NV4500 - Manual Transmission
ASSEMBLY

NOTE: Gaskets are not used in the transmission. Use Mopar Silicone Sealer or equivalent on all gear case and extension housing sealing surfaces.






COUNTERSHAFT AND REVERSE IDLER GEAR
1. Install countershaft front bearing cup in case with Handle C-4171 and Installer 6061-1.
2. Install front bearing on countershaft with Installer C-4340 (Fig. 64).
3. Lubricate countershaft front bearing cup and cone with petroleum jelly.






4. Position gear case on end with rear of case facing up (Fig. 65).
5. Install countershaft in gear case (Fig. 65).

NOTE: Do not install rear countershaft bearing on countershaft at this time.






6. Lubricate reverse idler gear bearings with petroleum jelly and install first bearing and second bearing (Fig. 66).
7. Install idler gear front thrust washer on boss in gear case (Fig. 66). Coat thrust washer with liberal quantity of petroleum jelly to hold it in place.






8. Install reverse idler gear in case (Fig. 67).
9. Install idler gear rear thrust washer between idler gear and case boss (Fig. 67).
10. Align idler gear bearings and thrust washers with a drift.







11. Install reverse idler shaft with notched end of shaft facing countershaft (Fig. 68).






12. Lift countershaft upward and position wood block between front of shaft and case (Fig. 69).






13. Install rear bearing cone on countershaft with Installer C-4040 (Fig. 70).
14. Remove wood block from under countershaft and lower countershaft front bearing into front bearing cup.
15. Lubricate countershaft rear bearing cup and cone with petroleum jelly.






16. Install countershaft rear bearing cup in gear case and over rear bearing (Fig. 71). Tap cup into place with plastic mallet if necessary.






17. Install countershaft rear bearing plate (Fig. 72).

NOTE: Verify plate is seated in notch in reverse idler shaft before tightening bearing plate bolts.






18. Apply Mopar silicone adhesive/sealer or equivalent to flange and lip of new cap. Install new front bearing cap in gear case (Fig. 73) with Handle C-4171 and Installer C-3972-A.







COUNTERSHAFT END PLAY
1. Rotate countershaft 4-5 times to seat bearings.
2. Mount dial indicator on case. Then position indicator plunger on end of countershaft and zero dial indicator (Fig. 74).
3. Raise countershaft with screwdriver and note end play reading on dial indicator. End play should be 0.051 - 0.15 mm (0.002 - 0.006 inch).
4. Remove countershaft rear bearing plate.






5. Install a end play shim that will provide minimum countershaft end play. Position shim on rear bearing cup (Fig. 75).
6. Install countershaft rear bearing plate (Fig. 72).

NOTE: Verify plate is seated in reverse idler shaft notch and end play shims are still in position before installing bolts.

7. Apply 1-2 drops Mopar Loc N' Seal or equivalent to threads of rear bearing plate bolts. Then install and tighten bearing plate bolts to 23 Nm (200 inch lbs.).


SHIFT LUG AND RAIL
1. Lubricate shift lug and rail with Castrol Syntorq or equivalent.
2. Insert shift lug rail part way into case.
3. Install shift lug on rail.






4. Position shift rail so roll pin notches are toward outside of case (Fig. 76).
5. Install roll pin that secures lug to rail (Fig. 76).



MAINSHAFT AND GEARTRAIN

CAUTION: The reverse, 1-2 and 3-4 synchro components can be assembled and installed incorrectly. Follow assembly procedures for component identification and location. Lubricate mainshaft bearing surfaces and all bearing assemblies with Castrol Syntorq or with petroleum jelly.







1. Install first snap ring in rear most groove of mainshaft hub (Fig. 77). This snap ring locates first gear clutch gear on shaft.

NOTE: Four of these snap rings are used to secure various components on the mainshaft 1-2 synchro hub. The snap rings are all the same size and are interchangeable.






2. Install first gear clutch cone on mainshaft 1-2 synchro hub with recessed side of cone facing front (Fig. 78). Verify cone is seated against snap ring on hub.






3. Install snap ring on mainshaft 1-2 synchro hub to secure clutch cone (Fig. 79). Verify snap ring is seated in hub groove and against clutch cone.
4. Support mainshaft in upright position to install remaining gears, snap rings and synchro components. Shaft can be supported in gear case or hole can be cut in workbench to support shaft.
5. If 1-2 synchro hub and sleeve were disassembled for service, reassemble hub, sleeve, struts and springs as follows:






a. Align and install sleeve on hub. Rotate sleeve until it slides onto hub. Sleeve only fits one way and will easily slide onto hub when long slot in sleeve, aligns with long shoulder on hub (Fig. 80).






b. Place wood blocks under hub that will raise hub about 3.5 cm (1.375 inch) above surface of workbench. Then allow sleeve to drop down on hub (Fig. 81).
c. Install springs and struts in hub (Fig. 81). Use lots of petroleum jelly to hold them in place. Then compress struts with your fingers and move sleeve upward until struts are started in sleeve. Verify that struts are engaged in sleeve before proceeding.
d. Turn synchro assembly upright. Then move sleeve into neutral position on hub and work struts into sleeve at same time. Be sure struts are seated and springs are not displaced during assembly.






6. Install first gear stop ring in 1-2 synchro hub and sleeve (Fig. 82). Verify stop ring is seated and engaged in hub and sleeve.






7. Install 1-2 synchro assembly and stop ring on mainshaft with the taper on the sleeve facing forward. (Fig. 83).






8. Install snap ring that secures 1-2 synchro on mainshaft hub (Fig. 84). Verify snap ring is seated in groove in mainshaft hub.






9. Assemble second gear clutch cone, clutch ring and stop ring (Fig. 85).






10. Install assembled second gear clutch cone and rings on mainshaft and in 1-2 synchro hub (Fig. 86).






11. Install snap ring that secures second gear clutch cone on mainshaft (Fig. 87). Use narrow blade screwdriver to work snap ring into hub groove as shown. Verify snap ring is seated in mainshaft groove.

NOTE: If snap ring will not fit in groove, clutch cone is slightly misaligned.






12. Install second gear bearing on mainshaft (Fig. 88).






13. Install second gear on mainshaft and bearing. Rotate gear until tabs of second gear clutch ring are seated in tab slots in gear (Fig. 89).






14. Install thrust washer pin in shaft (Fig. 90).






15. Install second gear thrust washer. Verify washer is seated on gear and pin (Fig. 91).






16. Install second gear thrust washer snap ring (Fig. 92). Verify snap ring is seated in mainshaft groove.
17. Install third gear bearing spacer on shaft and seat it against thrust washer snap ring (Fig. 92).






18. Install third gear bearing on mainshaft (Fig. 93). Bearing should be flush with mainshaft hub.


NOTE: If bearing is not flush with hub, the bearing spacer or snap ring was not installed.






19. Install third gear over bearing and onto mainshaft (Fig. 94).






20. Install synchro stop ring on third gear (Fig. 95). Verify stop ring is seated on cone taper.
21. If 3-4 synchro was disassembled for service, reassemble synchro components as follows:






a. Align and install synchro sleeve on hub (Fig. 96). Front side of hub has a narrow groove machined in it.
b. Insert all three synchro struts in slots machined in sleeve and hub (Fig. 96).
c. Install and seat synchro springs (Fig. 96). Use screwdriver to compress springs and seat them in struts and hub as shown.






22. Start 3-4 synchro assembly on mainshaft with the hub groove and sleeve groove both facing forward. Tap assembly onto shaft splines until hub is about 3 mm (0.125 inch) away from third gear stop ring. Then align stop ring with synchro sleeve and hub and seat synchro assembly with Installer C-4040 (Fig. 97).
23. Verify 3-4 synchro hub is seated on shaft with approximately 3 mm (0.125 inch) of shaft spline visible.

NOTE: If hub is not seated, stop ring lugs are misaligned. Rotate ring until lugs are engaged in 3-4 hub slots.

24. Verify that second and third gear rotate freely at this point. If not, determine the cause and correct.
25. Invert mainshaft in case or bench.
26. Install first gear bearing on mainshaft.






27. Install first gear on shaft with clutch hub side of gear facing the front of shaft (Fig. 98). Verify tabs on clutch ring are aligned and seated in first gear hub.

NOTE: 1-2 synchro hub will not seat properly if clutch ring tabs are misaligned.

28. Install reverse clutch gear on first gear (Fig. 98). Verify clutch gear is seated on shaft splines.
29. Install reverse clutch gear snap ring with heavy duty snap ring pliers (Fig. 98). Verify snap ring is seated in groove.




NOTE: Reverse gear will not fit properly if snap ring is not seated.






30. Install stop ring on clutch cone (Fig. 99). Verify stop ring is seated on cone taper.






31. Install reverse gear bearing spacer on mainshaft and seat against reverse clutch gear snap ring (Fig. 100).
32. Install reverse gear bearing on mainshaft (Fig. 100).
33. If reverse gear sleeve and struts were disassembled for service, reassemble sleeve, struts and springs as follows:

CAUTION: The reverse sleeve will fit either way on the hub. Verify tapered side of the sleeve faces rearward.






a. Position sleeve on hub so tapered side of sleeve faces rearward. (Fig. 101).
b. Rotate sleeve to align teeth on sleeve and hub. Sleeve will slide easily into place on hub when properly aligned.
c. Install springs in gear hub (Fig. 101). Use petroleum jelly to hold springs in place if desired.
d. Compress first spring with flat blade screwdriver and slide strut into position in hub slot. Then work spring into seat in strut with small hooked tool or screwdriver.
e. Install second and third struts in same manner as described in step (d).
f. Work sleeve upward on hub until struts are centered and seated in sleeve. Sleeve should be in neutral position after seating struts.






34. Install reverse gear and synchro assembly on mainshaft (Fig. 102). Rotate assembly until stop ring lugs engage in hub slots and gear drops into seated position.






35. Install reverse gear thrust washer (Fig. 103).






36. Install rear bearing on mainshaft with Installer 6446. Seat bearing on output shaft and against thrust washer (Fig. 104).






37. Install fourth gear stop ring in 3-4 synchro sleeve (Fig. 105).






38. Install fourth gear clutch gear in stop ring (Fig. 106).
39. Roll gear case onto its left side.
40. Grip mainshaft at pilot bearing hub and just behind reverse gear. Then lift assembly and guide rear of shaft through bearing bore at rear of case.
41. Continue holding front of shaft but switch grip at rear to shaft output splines. Lift mainshaft assembly slightly, align gears, and seat assembly in case.






42. Set transmission case upright (Fig. 107).






43. Install drive gear thrust bearing on mainshaft (Fig. 108). Use plenty of petroleum jelly to hold bearing in place.
44. Check alignment and mesh of mainshaft gears. If gears are not aligned, roll case on side and realign shaft and gears in case.






DRIVE GEAR AND RETAINER
1. Install bearing on drive gear with Installer 6448 (Fig. 109).
2. Lubricate pilot bearing with petroleum jelly and install it in drive gear bore.
3. Install drive gear on mainshaft. Work gear rearward until mainshaft hub is seated in pilot bearing.






4. Install bearing cup in front retainer with Handle C-4171 and Installer C-4308 (Fig. 110).






5. Install new oil seal in front bearing retainer with Installer 6052 (Fig. 111). Use one or two wood blocks to support retainer as shown. Lubricate seal lip with petroleum jelly after installation.
6. Clean contact surfaces of gear case and front bearing retainer with a wax and grease remover.






7. Apply Mopar Silicone Sealer or equivalent to flange surface of front bearing retainer (Fig. 112).
8. Install front bearing retainer over drive gear and start it into case.
9. Start front bearing retainer in gear case. Verify retainer lube channel is at the top-center (12 O'clock) position (Fig. 112).






10. Align front bearing retainer bolt holes and tap retainer into place with plastic mallet. Install new retainer bolts and tighten to 30 Nm (22 ft. lbs.) (Fig. 113).

NOTE: Never reuse the old bolts.








MAINSHAFT END PLAY
1. Install mainshaft rear bearing cup in case and over bearing. Tap bearing cup into place with plastic mallet.
2. Install rear bearing plate to hold mainshaft and rear bearing in position (Fig. 114).

NOTE: Do not install any end play shims at this time.

3. Tighten rear bearing plate bolts securely.
4. Place gear case in upright position on bench. Either cut hole in bench to accept drive gear and front retainer or use C-clamps to secure transmission on bench.

NOTE: Do not leave transmission unsupported.

5. Install Extension Rod 8161 into a suitable threaded hole in rear of case.
6. Mount dial indicator on extension rod and position indicator plunger against end of mainshaft.
7. Move mainshaft forward to remove all play then zero dial indicator.
8. Move mainshaft upward and record dial indicator reading. Move mainshaft with pry tool positioned between drive gear and case.
9. End play should be 0.051 - 0.15 mm (0.002 - 0.006 inch). Select fit shims are available to adjust end play. If end play adjustment is required, remove bearing plate and install necessary shim.
10. Reinstall rear bearing plate with oil hole in bearing plate at the top (Fig. 114).
11. Apply Mopar Lock N' Seal or equivalent to bearing plate bolt threads. Install and tighten bolts to 23 Nm (200 inch lbs.).






12. Install mainshaft fifth gear with Installer 6446 (Fig. 115). Gear is seated when it contacts rear bearing.






COUNTERSHAFT FIFTH GEAR SYNCHR0
1. Install thrust washer pin in countershaft (Fig. 116).






2. Install thrust washer on countershaft. Turn washer until pin engages in washer notch (Fig. 117).

NOTE: The flat side of washer faces the rear and cone side faces the front.






3. Lubricate and install fifth gear bearing on countershaft (Fig. 118).






4. Install synchro sleeve on hub of countershaft fifth gear with tapered side of sleeve facing front and the flat side facing rear (Fig. 119).






5. Install shift fork in synchro sleeve (Fig. 120).






6. Install assembled fifth gear, synchro sleeve and shift fork (Fig. 121). Align fork with shift lug rail and align gear with bearings and countershaft. Start components onto shaft and rail, then tap gear and fork into place with plastic or rawhide mallet.






7. Install fifth gear synchro struts and springs (Fig. 122).






8. Assemble and install fifth synchro clutch gear and stop ring in fifth gear hub (Fig. 123). Verify parts are seated in fifth gear hub.






9. Install clutch gear snap ring (Fig. 124).
10. Align roll pin holes in shift fork with notches in shift lug rail. Then install roll pins from top side of fork (Fig. 121).

NOTE: Roll pins only fit one way due to small shoulder at one end of each pin.


FIFTH GEAR NUT
1. Install belleville washer onto the mainshaft.
2. Install fifth gear nut over the mainshaft.
3. Tighten the clamp bolt until the gap in the clamp nut assembly is closed.
4. Back the clamp bolt off one full turn.
5. Place 10-15 drops of Loctite 272 onto the mainshaft threads where the fifth gear nut will be engaged.






6. Install fifth gear nut on mainshaft (Fig. 125).
7. Hold mainshaft Socket 6993 4X2 or Socket 6984 4X4 while installing the fifth gear nut.






8. Tighten fifth gear nut as much as possible with Nut Wrench 6743, long handle ratchet, breaker bar and applicable socket wrench (Fig. 126).
9. Lock mainshaft gears by shifting all synchro sleeves into engaged position.
10. Tighten fifth gear nut with Nut Wrench 6743 and high capacity torque wrench. Tighten nut to 366 - 380 Nm (270 - 280 ft. lbs.). Have helper hold transmission steady if necessary.
11. Torque the fifth gear clamp nut clamping bolt to 13.5 Nm (10 ft. lbs.).
12. Unlock the mainshaft gears by shifting all synchro sleeves out of the engaged position.



EXTENSION/ADAPTER HOUSING
1. Clean mating surfaces of extension/adapter housing and gear case with a wax and grease remover.
2. Check alignment dowels in gear case and housing or adapter. Be sure dowels are in position and seated.
3. Apply Mopar Silicone Sealer or equivalent to gear case and housing mating surfaces.






4. Align and install extension/adapter housing on gear case (Fig. 127).
5. Apply Mopar Lock N' Seal or equivalent to threads of extension/adapter housing bolts.
6. Install and tighten housing bolts to 54 Nm (40 ft. lbs.).
7. Install transfer case, if equipped.
8. Install engine rear support.
9. Install propeller shaft(s).
10. Remove transmission support stand and lower vehicle.