Disassembly
NV3500 - Manual TransmissionDISASSEMBLY
FRONT HOUSING
1. Shift transmission into Neutral.
2. If lubricant was not drained out of transmission during removal, remove drain plug and drain lubricant.
3. Inspect drain plug magnet for debris.
4. Remove backup light switch located on passenger side of rear housing (Fig. 5).
5. Remove shift tower bolts and remove tower and lever assembly (Fig. 6).
6. Remove shift shaft lock bolt (Fig. 7) from the top of front housing. The shoulder bolt secures the shift shaft bushing and lever.
7. Remove input shaft bearing retainer bolts from the front housing, then carefully pry on the retainer to break sealer bead loose (Fig. 8).
8. Remove bearing retainer from input shaft (Fig. 9)
9. Remove input shaft snap ring (Fig. 10).
10. Remove shift shaft detent plug with Remover 8117A. Attach fingers of the remover to the detent plug and push the cup down till it contacts the trans. Then tighten the nut till it pulls the plug from the case.
11. Remove shift shaft detent plunger and spring with a pencil magnet.
12. Remove bolts that attach front housing to the rear housing (Fig. 11). Three bolts at extreme rear of housing are for the output shaft bearing retainer. Leave one bolt in place until geartrain is ready to be removed from case.
13. Separate the housings (Fig. 12) by tapping the front housing off alignment dowels with a plastic hammer.
14. Remove input shaft bearing and countershaft front bearing race (Fig. 13).
15. Note position of input shaft, shift shaft, forks and geartrain components in housing (Fig. 14).
SHIFT/FORK SHAFTS AND REVERSE IDLER SEGMENT
1. Place a shop towel over the shaft lever to contain the lever detent ball and spring.
2. Rotate lever and bushing upward out of the shift forks and catch ball and spring (Fig. 15).
3. Unseat shift socket roll pin with Remover 6858. Position remover on shift shaft and center tool over the roll pin. Verify tool legs are firmly seated on the shift socket (Fig. 16).
4. Tilt socket toward the side of the case to avoid trapping the pin between the gear teeth.
5. Tighten remover to press the roll pin downward and out of the shift socket (Fig. 16).
NOTE: Roll pin must only clear the shift shaft. Do not push the pin into the geartrain.
6. Drive out shift bushing and lever roll pin with a hammer and punch (Fig. 17).
NOTE: Use proper size punch to avoid bending the shift shaft.
7. Pull shift shaft straight out of rear housing, shift socket, fifth-reverse fork and 1-2 fork (Fig. 18).
8. Remove shift socket from rear housing (Fig. 19).
9. Remove shaft lever and bushing (Fig. 20).
10. Rotate 3-4 fork around synchro sleeve until fork clears shift arms on 1-2 and fifth-reverse forks, then remove 3-4 fork (Fig. 21).
11. Remove reverse idler shaft support bolt and loosen rear reverse idler shaft bolt (Fig. 22).
12. Remove reverse idler shaft support segment by sliding it straight out of housing. 13. Support geartrain and rear housing on Fixture 6747 as follows:
a. Adjust height of reverse idler pedestal rod until the reverse idle shaft bottoms in Cup 8115.
b. Position Adapters 6747-1A and 6747-2B on Fixture 6747.
c. Slide fixture tool onto input shaft, countershaft and idler gear (Fig. 23).
d. Stand geartrain and rear housing upright on fixture (Fig. 24). Have helper hold fixture tool in place while housing and geartrain is being rotated into upright position.
14. Remove rear bolt holding reverse idler shaft in housing.
REAR HOUSING - 2WD
1. On 2-wheel drive transmission, remove three bolts that attach output shaft bearing retainer to rear case (Fig. 25). Bolts are rear of shift tower opening.
2. Tap rear housing upward and off output shaft bearing with a plastic/rawhide hammer (Fig. 26).
3. Lift rear housing up and off geartrain (Fig. 27).
4. Remove countershaft rear bearing from countershaft (Fig. 28).
GEARTRAIN FROM FIXTURE
1. Remove reverse idler gear assembly from assembly fixture cup.
2. Remove 1-2 and fifth-reverse forks from synchro sleeves.
3. Slide countershaft out of fixture tool.
4. Remove output shaft bearing retainer from rear surface of fifth gear (retainer will drop onto gear after bolts are removed).
5. Lift and remove output shaft and gears off input shaft.
6. Lift and remove input shaft, pilot bearing and fourth gear synchro ring from the fixture.
OUTPUT SHAFT
NOTE: Synchronizer hubs and sleeves are different and must not be mixed. Remove each synchronizer unit as an assembly to avoid mixing parts. Mark each synchro hub and sleeve with a scriber or paint for correct assembly reference.
1. Remove snap ring that secures 3-4 synchro hub on output shaft.
2. Position Bearing Splitter 1130 between second and third gears and press off 3-4 synchro assembly, third gear synchro ring and third gear with a shop press.
3. Remove third gear needle bearing (Fig. 34).
4. Remove retaining ring that secures two-piece thrust washer on shaft with a small pry tool (Fig. 35).
5. Remove two-piece thrust washer (Fig. 36) and note position of washer locating lugs in shaft notches for installation reference.
6. Remove second gear and needle bearing (Fig. 37).
7. Remove second gear synchro ring, synchro friction cone, synchro cone and interm ring (Fig. 38).
8. Remove 1-2 synchro hub snap ring.
9. Position Bearing Splitter 1130 between first and reverse gear. Press off 1-2 synchro hub, sleeve and first gear from output shaft with shop press (Fig. 39).
10. Remove first gear needle bearing (Fig. 40).
11. Remove output shaft bearing snap ring (Fig. 41).
12. On 2-wheel drive models, remove output shaft bearing.
13. Remove fifth gear (Fig. 42).
14. Remove fifth gear needle bearing. Spread bearing just enough to clear shoulder on output shaft (Fig. 43).
15. Remove fifth-reverse synchro hub snap ring (Fig. 44).
16. Remove fifth-reverse synchro hub and sleeve with shop press (Fig. 45).
17. Remove reverse gear and needle bearing (Fig. 46).
REVERSE IDLER
1. Remove idler gear snap rings (Fig. 47).
2. Remove thrust washer, wave washer, thrust plate and idler gear from shaft.
3. Remove idler gear needle bearing from shaft.