NV231 Transfer Case

Fig. 34 Drive sprocket bearing installation:

During assembly, lubricate all transfer case components with clean Dexron II type automatic transmission fluid.
1. Replace output shaft front bearing and seal as follows:
a. Remove shaft oil seal and bearing snap ring from front case.
b. Carefully tap bearing out of case using a plastic mallet.
c. Install new bearing using tools No. J-8092 and J-33833 or equivalents.
d. Install bearing snap ring, then the seal using tool No. J-33834 or equivalent.
2. Remove input gear bearing as follows:
a. Remove bearing from front case using tool No. J-29170 or equivalent and a press.
b. Position snap ring on new bearing, then install bearing using removal tool and a block of wood. Install bearing until snap ring seats against case.
3. Replace input gear pilot bearing as follows:
a. Remove pilot bearing using tool No. J-29369-1 or equivalent and a slide hammer.
b. Install new bearing using tool No. J-8092 and J-33829 or equivalents.
4. Install input gear thrust washers, input gear, retainer and snap ring into low range gear. Ensure snap ring fully seats in groove in gear.
5. Start input gear shaft into bearing in front case, then press gear shaft into front bearing using tool No. J-33829 or equivalent, and a press. Do not press against end surface of low range gear.
6. Install new input gear snap ring into case.
7. Install new front bearing retainer oil seal using tool No. J-33831 or equivalent.
8. Apply a 1/8 inch wide bead of RTV sealer to front bearing retainer sealing surface, then install retainer on front case. Torque retainer attaching bolts to 16 ft. lbs.
9. Install new sector shaft O-ring and bushing into case bore, then position range sector in case.
10. Install range lever on range sector shaft. Torque lever attaching nut to 22 ft. lbs.
11. Install detent plunger, spring and plug into case.
12. Install new pads and shift rail bushings into range fork.
13. Install range fork and shift hub assembly into case. Ensure range fork pin is properly engaged in sector shaft.
14. Replace drive sprocket bearings as follows:
a. Simultaneously press both bearings out of sprocket using tool No. J-29170 or equivalent and a press.
b. Install front bearing (A) using removal tool and a press until bearing is flush with edge of bore.
c. Install rear bearing (B), using removal tool and a press until bearing is 11/64 inch below edge of bore. If bearings are pressed in any further than specified, mainshaft oil feed hole may be blocked.
15. Install struts and spring into synchronizer hub.
16. Lubricate drive sprocket bearings, then install sprocket on mainshaft.
17. Slide synchronizer hub onto mainshaft, ensuring hub struts are properly seated in stop ring lugs.
18. Install new synchronizer hub snap ring.
19. Install synchronizer sleeve on hub, ensuring beveled spline end of sleeve faces stop ring.
20. Install new pads on mode fork, if necessary.
21. Engage mode fork in synchronizer sleeve, then install fork and rail and mainshaft assembly into case. Ensure mode fork shaft rail is properly seated in both range fork bushings.
22. Install output shaft and drive chain assembly, lifting mainshaft as necessary.
23. Install mode spring on shift rail.
24. Replace output shaft rear bearing as follows:
a. Remove bearing using tool No. J-29369-2 or equivalent and a slide hammer.
b. Install bearing using tools No. J-33826 and J-8092 or equivalents.
25. Assemble oil pump as follows:
a. Lubricate oil pump gears, then position gears in pump housing.
b. Align pump housing halves, then join halves and torque attaching screws to 14 inch lbs.
c. Install new pickup tube O-ring in oil pump.
26. Slide oil pickup tube into oil pump, then connect screen and hose to tube.
27. Install oil pump, pickup tube and screen assembly into rear case. Ensure screen is properly seated in case slot.
28. Install magnet in front case.
29. Apply a 1/8 inch wide bead of RTV sealer to front case sealing surface, then install front case to rear case, ensuring dowels and mainshaft splines are properly mated. Torque attaching bolts to 30 ft. lbs. A washer must be installed under each bolt at case dowel locations.
30. Replace rear bearing as follows:
a. Tap bearing out of rear retainer using a hammer and brass drift.
b. Install bearing using tools No. J-33833 and J-8092 or equivalents.
31. Apply a 1/8 inch wide bead of RTV sealer to rear retainer sealing surface.
32. Position locating dowel, if previously removed, in rear retainer, then install retainer. Torque attaching bolts to 18 ft. lbs.
33. Install new rear retainer snap ring, ensuring it seats fully in shaft groove.
34. Replace extension housing bushing as follows:
a. Remove rear extension housing seal.
b. Remove extension housing bushing using tools No. J-8092 and J-33839 or equivalents.
c. Install new bushing using tools No. J-8092 and J-33826 or equivalents.
d. Install new seal using tool No. J-33834 or equivalent.
35. Apply a 1/8 inch wide bead of RTV sealer to extension housing sealing surface, then install housing. Torque attaching bolts to 30 ft. lbs.
36. Install front yoke with a new washer and nut. Torque nut to 110 ft. lbs.
37. Install vacuum switch, using a new gasket.
38. Install drain plug and torque to 35 ft. lbs.
39. Add specified quantity of Dexron II type automatic transmission fluid to transfer case, then install fill plug and torque to 35 ft. lbs.