Nissan Pick-ups and Pathfinder 1989-1995

Transfer Case

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IDENTIFICATION



All 4wd models use a TX10A transfer case.

REMOVAL & INSTALLATION



See Figures 1, 2 and 3

  1. Disconnect the negative battery cable.
  2.  
  3. Raise the front of the vehicle and support it with jackstands.
  4.  
  5. Drain the fluid from the transmission and transfer cases.
  6.  
  7. Remove the front and rear driveshafts. Be sure to plug the oil seal openings after removal.
  8.  

Be very careful not to damage the transfer case spline, yoke or oil seal while removing the driveshafts.

  1. Remove the torsion bar spring.
  2.  



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Fig. Fig. 1: Removing the transfer control lever from the transfer case



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Fig. Fig. 2: Apply sealant here transfer case installation



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Fig. Fig. 3: Transfer case-to-transmission bolt locations

  1. Remove the second crossmember.
  2.  
  3. Disconnect the transfer control lever at the outer shift lever ball joint and position it out of the way.
  4.  
  5. Position a floor jack underneath the transfer case and remove the case-to-transmission mounting bolts. Separate the transfer case from the transmission and slowly lower it out and away from the transmission.
  6.  

To install:
  1. Carefully position the transfer case so that it mates with the transmission and tighten the mounting bolts to 23-30 ft. lbs. (31-41 Nm). On models with manual transmissions, be sure to coat the case mating surface with sealant.
  2.  
  3. Connect the transfer control lever to the outer shift lever and tighten the nut to 18-22 ft. lbs. (25-30 Nm).
  4.  
  5. Install the second crossmember and tighten the bolts to 43-58 ft. lbs. (59-78 Nm). Install the torsion bar spring.
  6.  
  7. Unplug the oil seals and install the two driveshafts.
  8.  
  9. Refill the transmission and transfer case with fluid, then lower the vehicle and connect the battery cable. Road test the truck and check for any leaks or improper operation.
  10.  

TROUBLESHOOTING



Slips Out of Gear (High-Low)


Shifting poppet spring weak
 
Bearing broken or worn
 
Shifting fork bent
 
Improper control rod adjustment
 

Hard Shifting


Lack of lubricant
 
Shift lever binding on shaft
 
Shifting poppet ball scored
 
Shifting fork bent
 
Low tire pressure
 

Backlash


Companion yoke loose
 
Transfer case loose on mounts
 
Internal parts excessively worn
 

Noisy


Low lubricant level
 
Bearings improperly adjusted or excessively worn
 
Gears worn or damaged
 
Improper alignment of driveshafts or U-joints
 

Oil Leakage


Excessive amount of lubricant in case
 
Vent clogged
 
Gaskets or seals leaking
 
Bearings loose or damaged
 
Driveshaft yoke mating surfaces scored
 

Overheating


Excessive or insufficient amount of lubricant
 
Bearing adjustment too tight
 

OVERHAUL



See Figures 4 through 8

Before Disassembly

Cleanliness is an important factor in the overhaul of the transfer case. Before opening up this unit, the entire outside of the transfer case should be cleaned, preferably with a high pressure washer such as a wash spray unit. During inspection and reassembly all parts should be thoroughly cleaned with solvent then dried with compressed air. Wiping cloths and rags should not be used to dry parts.

Wheel bearing grease, long used to hold thrust washers and lubricate parts, should not be used. Instead, lubricate the seals with clean transmission oil. Use ordinary, unmedicated petroleum jelly to hold the thrust washers and to ease assembly of the seals; it will not leave a harmful residue as grease often will. Do not use solvent on the neoprene seals or thrust washers, if they are to be reused.

Before installing bolts into aluminum parts, always dip the threads into clean transmission oil. Anti-seize compound can also be used to prevent bolts from galling the aluminum and seizing. Always use a torque wrench to keep from stripping the threads. The internal snaprings should be expanded and the external rings should be compressed, if they are to be reused. This will help insure proper seating when installed.



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Fig. Fig. 4: Exploded view of the transfer gear control-1989 models



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Fig. Fig. 5: Exploded view of the transfer gear control-1990 and later models



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Fig. Fig. 6: Transfer case components



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Fig. Fig. 7: Transfer case components



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Fig. Fig. 8: Transfer case shift control components

Case Disassembly
  1. While holding the companion flange with tool ST38060002, remove the companion flange nut.
  2.  
  3. Remove the rear case.
  4.  
  5. Remove the companion flange with tool ST33051001 or equivalent.
  6.  
  7. Remove the oil cover and oil gutter.
  8.  
  9. Remove the snapring from the 2-4 shift rod.
  10.  
  11. Remove the bolts securing the bearing retainer. This is necessary to remove the mainshaft from the center case.
  12.  
  13. Remove the bolts securing the center case to the front case and then separate the center case from the front case.
  14.  
  15. Measure the end-play of the low gear, if it's beyond 0.0079-0.0256 in. (0.2-0.65mm) check the low gear and the L and H hub for wear.
  16.  
  17. Disassemble the center case assembly as follows:
    1. Remove the snapring from the mainshaft.
    2.  
    3. Pull out the low gear with the L and H hub.
    4.  
    5. Remove the needle bearing of low gear.
    6.  
    7. Make sure the direction of the drive chain before removing it. (It must be reinstalled in the same direction.) Check whether the spring part of the drive chain is installed on the front or rear side.
    8.  
    9. Remove the mainshaft, front drive and drive chain as a set by tapping the front end of the mainshaft and the front driveshaft alternately. Be careful not to bend the drive chain.
    10.  

  18.  
  19. Disassemble the front case assembly as follows:
    1. Remove the switches, check plugs, check springs and check balls.
    2.  
    3. Remove the outer shift lever.
    4.  
    5. Remove the lock pin of the inner shift lever and drive out the cross-shaft with plug.
    6.  
    7. Remove the 2-4 shift rod.
    8.  
    9. Remove the L and H shift rod and fork assembly with coupling sleeve.
    10.  
    11. Remove the needle bearing from the main gear.
    12.  
    13. Remove the bolts securing the front case cover and then remove the case.
    14.  
    15. Remove the counter gear by tapping lightly.
    16.  
    17. Remove the main gear by tapping lightly.
    18.  

  20.  

Component Disassembly and Assembly
MAINSHAFT
  1. Check the end-play of the front drive sprocket with a dial indicator. If the end-play is beyond 0.008-0.020 in. (0.2-0.5mm), check the front drive sprocket and clutch gear for wear.
  2.  
  3. Remove the retaining ring, speedometer drive gear and the steel ball.
  4.  
  5. Remove the snapring and spacer.
  6.  
  7. Press out the front drive sprocket with mainshaft rear bearing and clutch gear together.
  8.  
  9. Remove the needle bearing.
  10.  
  11. Remove the bearing retainer, then remove the snapring and spacer.
  12.  
  13. Press the front bearing from the mainshaft.
  14.  

To assemble:
  1. Press the front bearing onto the mainshaft.
  2.  
  3. Install the spacer.
  4.  
  5. Select the proper snapring from the chart to allow a clearance of 0-0.0059 in. (0-0.15mm) between the snapring.
  6.  
  7. Install the mainshaft in the case.
  8.  

Cleaning and Inspection
CLEANING

During overhaul, all components of the transfer case (except bearing assemblies, neoprene seals and thrust washers) should be thoroughly cleaned with solvent and dried with air pressure prior to inspection and reassembly. Be sure all gasket sealing material is cleaned off of the case, cover plates and mounting flanges.

Proper cleaning of bearings is of utmost importance. Bearings should always be cleaned separately from other parts.

Soak all bearing assemblies in clean solvent or fuel oil. Bearings should never be cleaned in a hot solution tank. Wash the bearings in solvent until all old lubricant is loosened. Hold races so that bearings will not rotate; then clean bearings with a soft bristled brush until all dirt has been removed. Remove loose particles of dirt by tapping the bearing flat against a block of wood. Rinse bearings in clean solvent; then blow bearings dry with air pressure.

Do not spin bearings while drying.

After drying, rotate each bearing slowly while examining balls or rollers for roughness, damage, or excessive wear. Replace all bearings that are not in first class condition. After cleaning and inspecting bearings lubricate generously with recommended lubricant, then wrap each bearing in clean plastic bags until ready for reassembly.

INSPECTION
  1. Inspect all parts for discoloration or warpage.
  2.  
  3. Examine all gears and splines for chipped, worn, broken or nicked teeth. Small nicks or burrs may be removed with a fine abrasive stone.
  4.  
  5. Inspect the breather assembly to make sure that it is open and not damaged.
  6.  
  7. Check all threaded parts for damaged, stripped, or crossed threads.
  8.  
  9. Replace all gaskets, oil seals and snaprings.
  10.  
  11. Inspect housings, retainers and covers for cracks or other damage. Replace the damaged parts.
  12.  
  13. Inspect keys and keyways for condition and fit.
  14.  
  15. Inspect shift forks for wear, distortion or any other damage.
  16.  
  17. Check detent ball springs for free length, compressed length, distortion or collapsed coils.
  18.  
  19. Check bearing fit on their respective shafts and in their bores or cups. Inspect bearings, shafts and cups for wear.
  20.  

If either the bearings or cups are worn or damaged, it is advisable to replace both parts.

  1. Inspect all bearing rollers or balls for pitting or galling.
  2.  
  3. Examine the detent balls for corrosion or brinnelling. If shift bar detents show wear, replace them.
  4.  
  5. Replace all worn or damaged parts. When assembling the transfer case, coat all moving parts with recommended lubricant.
  6.  

Case Assembly
  1. Assemble the front case as follows:
    1. Install the main gear assembly by tapping lightly.
    2.  
    3. Apply sealant to the mating surface and bolts of the front case cover, then install it on the front case.
    4.  
    5. Apply gear oil to the needle bearing and install it into the main gear.
    6.  
    7. Install the counter gear assembly by tapping lightly.
    8.  
    9. Install the cross-shaft and inner shift lever. When replacing the cross-shaft, outer shift lever or lock pin of the outer shift lever, replace them as a set.
    10.  
    11. Apply sealant to the plug and install it into the front of the case.
    12.  
    13. Insert the interlock plunger into the front case.
    14.  
    15. Install the Low/High shift rod and fork assembly with the coupling sleeve.
    16.  
    17. Install the 2-4 shift rod.
    18.  
    19. Apply sealant to the switches, check balls, check springs and plugs.
    20.  

  2.  
  3. Select the counter gear rear bearing shim as follows:
    1. Seat the counter gear assembly.
    2.  
    3. Place special tools J34291-1 (bridge), J34291-2 (legs) and J34291-5 (gauging cylinder) on the machined surface of the center case and allow the gauging cylinder to rest on the top portion of the counter gear rear bearing. Lock the gauging cylinder in place.
    4.  
    5. Insert tool J34291-15 (gauging plunger) into J34291-5 (gauging cylinder).
    6.  
    7. Place the bridge, legs, gauging cylinder and gauging plunger onto the machined surface of the front case assembly and allow the gauging plunger to drop until it contacts the counter gear rear bearing mating surface.
    8.  
    9. Lock the gauging plunger in place and use a feeler gauge to measure the gap between the gauging cylinder and the gauging plunger.
    10.  
    11. Using the measured distance to obtain the correct shim size. The counter gear end-play should be 0-0.008 in. (0-0.2mm).
    12.  
    13. Select the counter gear rear bearing shim.
    14.  

  4.  
  5. Place a suitable shim on the counter gear rear bearing.
  6.  
  7. Apply gear oil to each part of the front case.
  8.  
  9. Assemble the center case assembly as follows:
    1. Apply gear oil to the mainshaft front bearing and install the mainshaft on the center case by tapping lightly.
    2.  
    3. Install the bearing retainer.
    4.  
    5. Put the drive chain onto the front drive sprocket and the front driveshaft and then put them in the center case. The chain must be installed in its original position as described during disassembly.
    6.  
    7. Install the front driveshaft by tapping lightly.
    8.  
    9. Apply gear oil to the needle bearings and while rotating them install them into the front drive sprocket.
    10.  
    11. Install the 2-4 coupling sleeve with the 2-4 shift fork.
    12.  
    13. Insert the shifting inserts and spread spring.
    14.  
    15. Install the baulk ring, then install the clutch gear and the mainshaft rear bearing.
    16.  
    17. Install the spacer.
    18.  
    19. Select a snapring to obtain the proper clearance of 0-0.0059 in. (0-0.15mm).
    20.  
    21. Install the steel ball, speedometer gear and the retaining ring. The steel ball is the smallest of all the check balls for this unit.
    22.  
    23. Apply gear oil to the needle bearing and then install the low gear and its bearing on the mainshaft.
    24.  
    25. Install the Low/High hub and the snapring to the mainshaft.
    26.  
    27. Check to end-play of low gear, it should be 0.0079-0.0256 in. (0.2-0.65mm).
    28.  

  10.  
  11. Apply sealant to the mating surface and place the center case assembly onto the front case and tighten the bolts.
  12.  
  13. Install the snapring to the 2-4 shift rod.
  14.  
  15. Install the oil gutter and oil cover.
  16.  
  17. Lubricate all the parts in the center case with gear oil.
  18.  
  19. Apply sealant to the mating surface, install the rear case to the center case and tighten the bolts.
  20.  

 
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