Disassembly
REMOVAL1. Shift transfer case into 2WD.
2. Raise vehicle.
3. Drain transfer case lubricant.
4. Mark front and rear propeller shafts for alignment reference.
5. Support transmission with jack stand.
6. Remove the transfer case skid plate, if equipped.
7. Disconnect front and rear propeller shafts at transfer case.
8. Disconnect transfer case shift motor and mode sensor wire connectors.
9. Disconnect transfer case vent hose.
10. Support transfer case with transmission jack.
11. Secure transfer case to jack with chains.
12. Remove nuts attaching transfer case to transmission (Fig. 2).
13. Pull transfer case and jack rearward to disengage transfer case.
14. Remove transfer case from under vehicle.
DISASSEMBLY
Position transfer case in a shallow drain pan. Remove drain plug and drain any remaining lubricant remaining in case.
SHIFT MOTOR ASSEMBLY AND FRONT OUTPUT SHAFT SEAL
1. Remove the bolts (Fig. 3) which hold the shift motor and mode sensor assembly to the transfer case.
2. Remove the shift motor and mode sensor assembly from the transfer case.
3. Remove the front propeller shaft seal boot retaining clamp (Fig. 4).
4. Remove the front propeller shaft seal boot (Fig. 5).
5. Remove the front output shaft seal slinger by bending (Fig. 6) the slinger ears away from the transfer case.
6. Using a suitable pry tool (Fig. 7), remove the slinger from the output shaft using care not to damage the shaft.
7. Using a screw and a slide hammer, remove the front output shaft seal.
REAR EXTENSION
1. Remove rear extension bolts (Fig. 8).
2. Remove rear extension housing (Fig. 9). Tap extension once or twice with a plastic mallet to break sealer bead and loosen it.
3. Remove output bearing retaining ring with heavy duty snap-ring pliers (Fig. 10).
OIL PUMP AND REAR CASE
1. Remove rear case-to-front case bolts (Fig. 11).
2. Loosen rear case with pry tool to break sealer bead. Insert tool in slot at each end of case (Fig. 12).
3. Unseat rear case from alignment dowels.
4. Remove rear case and oil pump assembly from front case (Fig. 13).
CAUTION: Do not remove the bolts holding the oil pump cover to the rear case half. The oil pump cover is aligned to the rear output shaft inner bearing race and will become misaligned if the bolts are loosened. If the transfer case failure has generated any debris which may have become trapped in the oil pump, the rear case and oil pump assembly MUST be replaced.
5. Remove the oil pump pickup tube.
FRONT OUTPUT SHAFT AND DRIVE CHAIN
1. Remove shift rail cup and spring (Fig. 14).
2. Remove front sprocket retaining ring (Fig. 15).
3. Pull mainshaft, front sprocket and chain outward about 25.4 mm (1-inch) simultaneously (Fig. 16).
4. Remove chain from mainshaft drive sprocket and remove front sprocket and chain as assembly.
SHIFT FORKS AND MAINSHAFT
1. Loosen detent plug.
2. Remove detent plug, spring, and plunger (Fig. 17). Note that the plug has an O-ring seal. Remove and discard this seal.
3. Remove the front output shaft snap-ring (Fig. 18).
4. Remove front output shaft from bearing in case (Fig. 19).
5. Pull mainshaft assembly out of input gear, mode sleeve, and case (Fig. 20).
6. Remove mode fork, mode sleeve, and shift rail as assembly (Fig. 21). Note which way the sleeve fits in the fork (long side of sleeve goes to front).
7. Remove range fork retaining ring.
8. Remove range fork and hub as an assembly (Fig. 22). Note fork position for installation reference.
9. Remove shift sector (Fig. 23).
10. Remove the shift sector O-ring (Fig. 24).
MAINSHAFT
1. Remove the drive sprocket retaining ring (Fig. 25) from the output shaft.
2. Remove the drive sprocket thrust washer (Fig. 26) from the output shaft.
3. Remove drive sprocket (Fig. 27) from the output shaft.
4. Remove the clutch gear (Fig. 28) and hub (Fig. 29) from the output shaft.
5. Remove the mode hub retaining ring (Fig. 30) from the output shaft.
6. Remove the mode hub (Fig. 31) from the output shaft.
INPUT AND PLANETARY GEAR
1. Remove input gear seal with suitable screw and slide hammer.
2. Remove input gear retaining ring (Fig. 32) with heavy duty snap-ring pliers.
3. Place front case in horizontal position. Then remove input gear and low range gear as an assembly (Fig. 33). Tap gear out of bearing with plastic mallet, if necessary.
INPUT AND PLANETARY GEAR
1. Remove snap-ring that retains input gear in low range gear (Fig. 34).
2. Remove retainer (Fig. 35).
3. Remove front tabbed thrust washer (Fig. 36).
4. Remove input gear (Fig. 37).
5. Remove rear tabbed thrust washer from low range gear (Fig. 38).
CLEANING
Clean the transfer case parts with a standard parts cleaning solvent. Remove all traces of sealer from the cases and retainers with a scraper and 3M all purpose cleaner. Use compressed air to remove solvent residue from oil feed passages in the case halves, retainers, gears, and shafts.
INSPECTION
MAINSHAFT/SPROCKET/HUB INSPECTION
Inspect the splines on the hub and shaft and the teeth on the sprocket. Minor nicks and scratches can be smoothed with an oilstone. However, replace any part that is damaged. Check the contact surfaces in the sprocket bore and on the mainshaft. Minor nicks and scratches can be smoothed with 320-400 grit emery cloth but do not try to salvage the shaft if nicks or wear is severe.
INPUT GEAR AND PLANETARY CARRIER
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Check the teeth on the gear (Fig. 39). Minor nicks can be dressed off with an oilstone but replace the gear if any teeth are broken, cracked, or chipped. The bearing surface on the gear can be smoothed with 300-400 grit emery cloth if necessary.
Examine the carrier body and pinion gears for wear or damage. The carrier will have to be replaced as an assembly if the body pinion pins, or pinion gears are damaged.
Check the lock ring and both thrust washers for wear or cracks. Replace them if necessary. Also replace the lock retaining ring if bent, distorted, or broken.
SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork shift rail (Fig. 40). Minor nicks on the shift rail can be smoothed with 320-400 grit emery cloth.
Inspect the shift fork wear pads (Fig. 41). The mode and range fork pads are serviceable and can be replaced if necessary. Check both of the sleeves for wear or damage, especially on the interior teeth. Replace the sleeves if wear or damage is evident.
REAR EXTENSION HOUSING
Inspect the extension housing seal and bushing. Replace both components if either show any sign of wear or damage.
FRONT OUTPUT SHAFT AND DRIVE CHAIN
Inspect the shaft threads, sprocket teeth, and bearing surfaces. Minor nicks on the teeth can be smoothed with an oilstone. Use 320-400 grit emery to smooth minor scratches on the shaft bearing surfaces. Rough threads on the shaft can be chased if necessary. Replace the shaft if the threads are damaged, bearing surfaces are scored, or if any sprocket teeth are cracked or broken.
Examine the drive chain and shaft bearings. Replace the chain and both sprockets if the chain is stretched, distorted, or if any of the links bind. Replace the bearings if rough, or noisy.
LOW RANGE ANNULUS GEAR
Inspect annulus gear condition carefully. The gear is only serviced as part of the front case. If the gear is damaged, it will be necessary to replace the gear and front case as an assembly Do not attempt to remove the gear (Fig. 42)
FRONT AND REAR CASES
Inspect the cases for wear and damage.
Check case condition. If leaks were a problem, look for gouges and severe scoring of case sealing surfaces. Also make sure the front case mounting studs are in good condition. Check the front case mounting studs and vent tube. The tube can be secured with Loctite 271 or 680 if loose. The stud threads can be cleaned up with a die if necessary. Also check condition of the fill/ drain plug threads in the rear case. The threads can be repaired with a thread chaser or tap if necessary. Or the threads can be repaired with Helicoil stainless steel inserts if required.
OIL PUMP/OIL PICKUP
Examine the oil pump pickup parts. Replace the pump if any part appears to be worn or damaged. Do not disassemble the pump as individual parts are not available. The pump is only available as a complete assembly The pickup screen, hose, and tube are the only serviceable parts and are available separately.