Disassembly
DISASSEMBLY / NV3500 Manual TransmissionFRONT HOUSING
1. Shift transmission into Neutral.
2. Remove drain plug and drain lubricant.
3. Inspect drain plug magnet for debris.
4. Remove backup light switch. Switch is located on passenger side of rear housing (Fig. 1).
5. Remove shift tower bolts and remove tower and lever assembly (Fig. 2).
6. Remove shift shaft lock bolt (Fig. 3) located on top of the housing just forward of shift tower.
7. Remove shift shaft detent plug with Remover 811 7A. Attach the fingers of the remover to the detent plug (Fig. 4). Then push the cup down till it contacts the trans. Tighten the nut (Fig. 5) till it pulls the plug from the bans case.
8. Remove shift shaft detent plunger and spring. Remove spring and plunger with a pencil magnet.
9. Remove bolts attaching input shaft bearing retainer to front housing and remove retainer.
NOTE: Use pry tool to carefully lift retainer and break sealer bead (Fig. 6).
10. Remove bearing retainer from input shaft (Fig. 7).
11. Remove snap ring that secures input shaft in front bearing (Fig. 8).
12. Remove bolts that attach front housing to rear housing (Fig. 9). Three bolts at extreme rear of housing are actually for the output shaft bearing retainer. It is not necessary to remove all three bolts at this time. Leave at least one bolt in place until geartrain is ready to be removed from case.
13. Separate front housing from rear housing (Fig. 10). With a plastic mallet tap the front housing off the alignment dowels.
14. Remove and inspect input shaft bearing and countershaft front bearing race (Fig. 11).
15. Remove screw from reverse blocker and remove blocker (Fig. 12) from case.
16. Note position of input shaft, shift shaft, forks and geartrain components in housing (Fig. 13).
SHIFT/FORK SHAFTS AND REVERSE IDLER SEGMENT
1. Unseat the roll pin that secures the shift socket to the shift shaft with Remover 6858 as follows:
a. Position remover on the shift shaft. Center the tool over the roll pin and verify that the tool legs are firmly seated on the shift socket (Fig. 14).
b. Tilt the socket toward the side of the case. This positions the roll pin at a slight angle to avoid trapping the pin between the gear teeth.
c. Tighten the tool to press the roll pin downward and out of the shift socket (Fig. 14).
NOTE: Press the roll pin just enough to clear the shift shaft. Be careful not to push the pin into the geartrain.
2. Rotate lever and bushing upward and out of the shift forks and catch detent ball and spring (Fig. 15) as they exit the shaft lever.
NOTE: Place shop towel over shaft to contain detent ball and spring.
3. Drive out roll pin that secures shift bushing and lever to shift shaft (Fig. 16) with a hammer and punch.
CAUTION: Use proper size punch to avoid bending the shift shaft.
4. Pull shift shaft straight (Fig. 17) out of rear housing.
5. Remove shift socket from rear housing (Fig. 18).
6. Remove lever and bushing (Fig. 19).
7. 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. 20).
8. Remove the reverse idler shaft support bolt (front bolt) (Fig. 21).
9. Loosen rear reverse idler shaft bolt (rear bolt) (Fig. 21).
10. Remove reverse idler shaft support (Fig. 22) segment by sliding it straight out of housing.
11. 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.
12. 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. Unseat output shaft bearing from bearing bore in rear housing. Use plastic/rawhide mallet to tap rear housing upward and off output shaft bearing as shown (Fig. 26).
3. Lift rear housing up and off geartrain (Fig. 27).
4. Remove countershaft rear bearing from countershaft (Fig. 28).
5. Examine condition of bearing bore and idler shaft notch in rear housing. Replace housing if any of these components are damaged.
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 assembly fixture tool.
OUTPUT SHAFT
NOTE: The synchronizer hubs and sleeves are different and must not be intermixed. Remove each synchronizer unit as an assembly, to avoid intermixing parts. Reference mark or tag each synchro hub and sleeve for correct assembly.
1. Remove snap ring that secures 3-4 synchro hub on output shaft.
2. Remove 3-4 synchro assembly, third gear synchro ring and third gear with shop press and Bearing Splitter 1130. Position splitter between second and third gears.
3. Remove third gear needle bearing (Fig. 34).
4. Remove retaining ring that secures two-piece thrust washer on shaft (Fig. 35). Use a small pry tool to remove retaining ring.
5. Remove two-piece thrust washer (Fig. 36).
NOTE: Record location 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 and synchro cone (Fig. 38).
8. Remove interim ring.
9. Remove 1-2 synchro hub snap ring.
10. Remove 1-2 synchro hub and sleeve and first gear from output shaft with press and Bearing Splitter 1130 (Fig. 39). Position splitter between first and reverse gears.
11. Remove first gear needle bearing (Fig. 40).
12. Remove output shaft bearing snap ring (Fig. 41).
13. On 2-wheel drive models, remove output shaft bearing.
14. Remove fifth gear (Fig. 42).
15. Remove fifth gear needle bearing. Spread bearing apart just enough to clear shoulder on output shaft (Fig. 43).
16. Remove fifth-reverse synchro hub snap ring (Fig. 44).
17. Remove fifth-reverse synchro hub and sleeve with a press (Fig. 45).
18. 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.