2007 Liberty KJ Factory Service Manual 21 - TRANSMISSION AND TRANSFER CASE

TRANSFER CASE - NV241 GENII

DESCRIPTION

The NV241 GENII transfer case is a part-time transfer case with a low-range gear system. It provides three operating ranges plus a NEUTRAL position. The low range position provides a gear reduction ratio of 2.72:1 for increased low speed torque capability.

The gear cases and extension are all of aluminum. Drive sprockets and an interconnecting drive chain are used to transmit engine torque to the front/rear propeller shafts. The mainshaft, input gear and front output shaft are supported by ball and needle bearings.


IDENTIFICATION



An identification tag (2) is attached to the rear case of every transfer case. The tag provides the transfer case model number, assembly number, serial number, and low range ratio.

The transfer case serial number also represents the date of build.

OPERATION

OPERATING RANGE

Transfer case operating ranges are:

  • 2H (2-wheel drive)
  • 4H (4-wheel drive)
  • 4LO (4-wheel drive low range

The 2H range is for use on any road surface at any time.

The 4H and 4LO ranges are for off road use only. They are not for use on hard surface roads. The only exception being when the road surface is covered by ice and snow.

The low range reduction gear system is operative in 4LO range only. This range is for extra pulling power in off road situations. Low range reduction ratio is 2.72:1.


SHIFT MECHANISM

Operating ranges are selected with a floor mounted shift lever. The shift lever is connected to the transfer case range lever by a shift cable. A straight line shift pattern is used. Range positions are marked on the shifter knob bezel.


SHIFTING

The transfer case can be shifted between the 2H and 4H operating ranges while the vehicle is in motion. The vehicle must have the transmission placed in NEUTRAL, or the clutch depressed in the case of a manual transmission, and be moving less than 2-3 MPH when shifting into and out of the 4L operating range.

DIAGNOSIS AND TESTING - TRANSFER CASE - NV241 GENII

Before beginning repair on a suspected transfer case malfunction, check all other driveline components beforehand.

The actual cause of a problem may be related to such items as: front hubs, axles, propeller shafts, wheels and tires, transmission, or clutch instead. If all other driveline components are in good condition and operating properly, refer to the Diagnosis Chart for further information.


DIAGNOSIS CHART

Condition
  		 Possible Cause
  		 Correction
  
Transfer Case difficult to shift or will not shift into desired range.
  		 1) Vehicle speed too great to permit shifting.
  		 1) Stop vehicle and shift into desired range. Or, reduce speed to below 3-4 km/h (2-3 mph) before attempting the shift.
  
2) If vehicle was operated for an extended period in 4H on a dry paved surface, the driveline torque load may be causing a bind.
  		 2) Stop vehicle and shift the transmission into neutral. Shift the transfer case to 2H and operate vehicle in 2H on dry paved surfaces.
  		  
3) Transfer case external shift linkage binding.
  		 3) Lubricate, repair, or replace linkage bushings, or tighten loose components as necessary.
  		  
4) Insufficient or incorrect lubricant.
  		 4) Drain and refill to edge of fill hole with Mopar® ATF +4, Automatic Transmission fluid.
  		  
5) Internal components binding, worn, or damaged.
  		 5) Disassemble the transfer case and replace worn or damaged components as necessary.
  		  
Transfer Case noisy in all operating ranges.
  		 1) Insufficient or incorrect lubricant.
  		 1) Drain and refill to edge of fill hole with Mopar® ATF +4, Automatic Transmission fluid.
  
Noisy in, or jumps out of, four wheel drive low range.
  		 1) Transfer case not completely engaged in 4L position.
  		 1) With the transmission in NEUTRAL, or the clutch depressed in the case of a manual transmission and the vehicle moving under 3-4 km/h (2-3 mph), shift the transfer case to NEUTRAL and then shift into the 4L position.
  
2) Shift linkage out of adjustment.
  		 2) Adjust linkage.
  		  
3) Shift linkage loose or binding.
  		 3) Tighten, lubricate, or repair linkage as necessary.
  		  
4) Range fork damaged, inserts worn, or fork is binding on the shift rail.
  		 4) Disassemble unit and repair as necessary.
  		  
5) Low range gear worn or damaged.
  		 5) Disassemble unit and repair as necessary.
  		  
Lubricant leaking from output shaft seal or vent.
  		 1) Transfer case overfilled.
  		 1) Drain lubricant to the correct level.
  
2) Vent closed or restricted.
  		 2) Clear or replace vent as necessary.
  		  
3) Output shaft seals damaged or installed incorrectly.
  		 3) Replace seal as necessary. Check to ensure that another component, the propeller shaft slip yoke for example, is not causing damage to seal.
  		  
Abnormal tire wear.
  		 1) Extended operation on hard, dry surfaces in the 4H position.
  		 1) Operate vehicle in the 2H position on hard, dry surfaces.
  

REMOVAL




1. Shift transfer case into NEUTRAL.
2. Raise vehicle.
3. Remove skid plate (1).


4. Drain transfer case lubricant.
5. Mark front and rear propeller shaft yokes for alignment reference.
6. Remove the front/rear propeller shafts at transfer case. (Refer to 3 - DIFFERENTIAL & DRIVELINE/PROPELLER SHAFT/PROPELLER SHAFT - REMOVAL)
7. Disconnect transfer case position sensor connector (1) from the position sensor (2).


8. Disconnect transfer case shift cable (2) at the range lever.
9. Disconnect the transfer case shift cable (2) from the shift cable bracket (5).


10. Disconnect transfer case vent hose (3).
11. Support transfer case (2) with transmission jack.
12. Secure transfer case to jack with chains.
13. Remove nuts attaching transfer case to transmission (1).
14. Pull transfer case and jack rearward to disengage transfer case.
15. 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.


COMPANION FLANGE AND RANGE LEVER




1. Remove transfer case position sensor (1).


2. Install two bolts (2) partially into the propellor shaft companion flange (3), 180° from each other.
3. Install the rectangular end of the Flange Holder C-3281 (1) over the bolts to hold the companion flange stationary and remove the nut holding the companion flange to the output shaft.


4. Use Remover C-452 (3) to remove the companion flange (2).


5. Remove seal washer from front output shaft. Discard washer as it should not be reused.
6. Remove the bolt (2) that attaches the range lever (1) to sector shaft. Then move sector to neutral position and remove range lever from shaft.

NOTE: Be sure to note the orientation of the range lever (lever up or down) so that it may be re-installed in the same direction.


REAR EXTENSION




1. Remove rear extension (1) bolts.


2. Remove rear extension housing (1). Tap extension once or twice with a plastic mallet to break sealer bead and loosen it.


3. Remove output bearing (2) retaining ring (3) with heavy duty snap-ring pliers.

OIL PUMP AND REAR CASE




1. Remove rear case(1)-to-front case (2) bolts (3).


2. Loosen rear case (1) with pry tool to break sealer bead. Insert tool in slot (3) at each end of case.


3. Unseat rear case (1) from alignment dowels.
4. Remove rear case and oil pump assembly from front case.

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 bearing inner race and will become mis-aligned 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.


FRONT OUTPUT SHAFT AND DRIVE CHAIN




1. Remove shift rail (1) cup (3) and spring (2).


2. Remove front sprocket (1) retaining ring (2).


3. Pull mainshaft (3), front sprocket (1) and chain outward about 25.4 mm (1-inch) simultaneously.
4. Remove chain from mainshaft drive sprocket and remove front sprocket and chain as assembly.

SHIFT FORKS AND MAINSHAFT




1. Loosen detent plug (2).
2. Remove detent plug (2), spring (3), and plunger (4). Note that the plug has an O-ring seal. Remove and discard this seal.


3. Remove front output shaft (2) from bearing in the front case (1).


4. Pull mainshaft assembly (2) out of input gear, mode sleeve, and front case (1).


5. Remove mode fork (1), mode sleeve (3), and shift rail (2) as assembly. Note which way the sleeve fits in the fork (long side of sleeve goes to front).


6. Remove range fork retaining ring.
7. Remove range fork (2) and hub (1) as an assembly. Note fork position for installation reference.


8. Remove the shift sector support (1).


9. Remove shift sector (1).

MAINSHAFT




1. Remove the drive sprocket retaining ring (2) from the output shaft (1).


2. Remove the drive sprocket (3) thrust washer (2) from the output shaft (1).


3. Remove drive sprocket (2) from the output shaft (1).


4. Remove the clutch gear (2) from the output shaft (1).

Remove the sprocket hub (2) from the output shaft (1).


5. Remove the mode hub (3) retaining ring (2) from the output shaft (1).


6. Remove the mode hub (2) from the output shaft (1).

INPUT AND PLANETARY GEAR




1. Remove input gear seal with suitable screw and slide hammer.
2. Remove input gear (1) retaining ring (2) with heavy duty snap-ring pliers.


3. Place front case in horizontal position. Then remove input gear and low range gear as an assembly (2). Tap gear out of bearing with plastic mallet, if necessary.

INPUT AND PLANETARY GEAR




1. Remove snap-ring (1) that retains input gear in low range gear.


2. Remove retainer (3).


3. Remove front tabbed thrust washer (1).


4. Remove input gear (1).


5. Remove rear tabbed thrust washer (2) from low range gear (1).

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

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






Input Gear And Carrier Components


1 - PLANETARY CARRIER
  		 4 - CARRIER LOCK RING
  
2 - REAR THRUST WASHER
  		 5 - CARRIER LOCK RETAINING RING
  
3 - FRONT THRUST WASHER
  		 6 - INPUT GEAR
  

Check the teeth on the input gear (6). 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 planetary carrier body (1) 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 carrier lock ring (4) and both thrust washers (2, 3) for wear or cracks. Replace them if necessary. Also replace the carrier lock retaining ring (5) if bent, distorted, or broken.


SHIFT FORKS/HUBS/SLEEVES



Check condition of the shift forks and mode fork shift rail (2). Minor nicks on the shift rail can be smoothed with 320-400 grit emery cloth.



Inspect the shift fork wear pads (3, 4). The mode fork pads are serviceable and can be replaced if necessary. The range fork pads are not serviceable. The fork must be replaced as an assembly if the pads are worn or damaged.

Check both of the sleeves for wear or damage, especially on the interior teeth. Replace the sleeves if wear or damage is evident.


REAR RETAINER COMPONENTS

Inspect the retainer components. Replace the bearing if rough or noisy. Check the retainer for cracks or wear in the bearing bore.

Inspect the retaining rings and washers. Replace any part if distorted, bent, or broken. Reuse is not recommended.

Inspect rear extension bushing. Replace if worn or scored.


DRIVE CHAIN

Examine the drive chain and shaft bearings. replace the chain if stretched, distorted, or if any of the links bind. Replace the bearings if rough, or noisy.


LOW RANGE ANNULUS GEAR



Inspect annulus gear (2) 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.


FRONT CASE AND REAR CASE

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.

ASSEMBLY


BEARINGS AND SEALS




1. Remove the input shaft bearing (1) from the front case (2) with suitable snap-ring pliers.
2. Transfer the retaining ring to the new bearing if necessary and install the bearing into the front case.


3. Using Installer 6436 (2) and Handle C-4171 (3), remove front output shaft bearing.
4. Start front output shaft bearing in case. Then seat bearing with Handle C-4171 and Installer 6953.
5. Install front output shaft bearing retaining ring.


6. Remove input gear pilot bearing by inserting a suitably sized drift (1) into the splined end of the input gear (2) and driving the bearing out with the drift and a hammer.
7. Install new pilot bearing with Remover/Installer 8684.


8. Remove the front output shaft rear bearing with the screw and jaws from Remover L-4454 (2) and Cup 8148 (3).


9. Install new bearing with Tool Handle C-4171 (1) and Installer 5066 (3).


10. The bearing bore is chamfered (1) at the top. Install the bearing so it is flush with the lower edge of this chamfer.


11. Remove the rear output shaft bearing from the rear case using Remover/Installer 8684 (2) and Handle C-4171 (3).


12. Install the rear output shaft bearing into the rear case (1) using Remover/Installer 6953 (2) and Handle C-4171 (3).

INPUT AND PLANETARY GEAR




1. Lubricate gears (3, 4) and thrust washers (5) with recommended transmission fluid.
2. Install first thrust washer (5) in low range gear (3). Be sure washer tabs are properly aligned in gear notches.
3. Install input gear (3) in low range gear (4). Be sure input gear is fully seated.
4. Install remaining thrust washer (5) in low range gear (4) and on top of input gear (3). Be sure washer tabs are properly aligned in gear notches.
5. Install retainer (2) on input gear and install snap-ring (1).


6. Align and install low range/input gear assembly (2) in front case (1). Be sure low range gear pinions are engaged in annulus gear and that input gear shaft is fully seated in front bearing.


7. Install snap-ring (2) to hold input/low range gear (1) into front bearing.
8. Install a new input gear seal using Installer 8841 and Handle C-4171.

SHIFT FORKS AND MAINSHAFT




1. Lubricate mainshaft splines with recommended transmission fluid.
2. Install the mode hub (1) onto the output shaft.


3. Install the mode hub retaining ring (2) onto the output shaft (1).


4. Install the sprocket hub (2) onto the output shaft (1).


5. Install the clutch gear (2) onto the output shaft (1).


6. Install the drive sprocket (2) onto the output shaft (1).


7. Install the drive sprocket (3) thrust washer (2) onto the output shaft (1).


8. Install the drive sprocket retaining ring (2) onto the output shaft (1).


9. Lubricate sector shaft with transmission fluid and install shift sector (1) in case. Position slot in sector so it will be aligned with shift fork pin when shift forks are installed.


10. Install the shift sector support (1). Tighten the sector support to 27-42 N·m (20-30 ft.lbs.).


11. Assemble and install range fork (2) and hub (1). Be sure hub is properly seated in low range gear and engaged to the input gear.
12. Align and insert range fork pin in shift sector slot.
13. Install the range fork retaining ring.


14. Install mode fork (1) and shift rail (2) onto the mode sleeve (3).
15. Install the mode fork, sleeve, and shift rail into the transfer case.


16. Install mainshaft (2) into the transfer case (1). Guide mainshaft through the mode and range sleeves and into the input gear.


17. Install new o-ring on detent plug (2).


18. Install detent plunger (4), spring (3), and plug (2). Tighten the plug to 16-25 N·m (12-18 ft. lbs.).

FRONT OUTPUT SHAFT AND DRIVE CHAIN




1. Install the front output shaft (2) into the front output shaft bearing.


2. Insert front sprocket in drive chain.
3. Install drive chain (2) around mainshaft sprocket (1). Then position front sprocket over front shaft.
4. Raise mainshaft about 2.54 cm (one inch) and seat front sprocket on front output shaft.


5. If mainshaft and mode sleeve were unseated during chain installation, align and reseat mainshaft in input gear and hub.
6. Install front sprocket (1) retaining ring (2).


7. Install spring (2) and cup (1) on shift rail.


8. Insert magnet (1) in front case pocket (2).

OIL PUMP AND REAR CASE



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 mis-aligned 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.


1. Apply bead of Mopar® Gasket Maker, or equivalent, to mating surface of front case. Keep sealer bead width to maximum of 3/16 inch. Do not use excessive amount of sealer as excess will be displaced into case interior.
2. Align oil pump with mainshaft and align shift rail with bore in rear case. Then install rear case (1) and oil pump assembly.


3. Install 4-5 rear case(1)-to front case (2) bolts to hold rear case in position. Tighten bolts snug but not to specified torque at this time.

CAUTION: Verify that shift rail, and case alignment dowels are seated before installing any bolts. Case could be cracked if shaft rail or dowels are misaligned.




4. Apply Loctite™ 242 to remainder of rear case-to-front case bolt threads and install bolts. Tighten bolts to 20-27 N·m (15-24 ft. lbs.),
5. Install rear output bearing (2) snap-ring (3) to output shaft.

REAR EXTENSION




1. Install new seal in rear extension housing seal with Installer D-163 and Handle C-4171..
2. Apply bead of Mopar® Gasket Maker, or equivalent, to mating surface of rear extension housing. Keep sealer bead width to maximum of 3/16 inch. Do not use excessive amount of sealer as excess could be displaced into output bearing.
3. Align and install rear extension housing (1) on retainer.
4. Apply Mopar® Silicone Sealer to threads of rear extension housing bolts. Then install and tighten bolts to 16-24 N·m (12-18 ft. lbs.) torque.

COMPANION FLANGE AND RANGE LEVER




1. Install range lever (1) and bolt (2) on sector shaft. Tighten bolt to 27-34 N·m (20-25 ft. lbs.) torque.


2. Inspect the o-ring on the transfer case position sensor. Replace the o-ring if necessary.
3. Install the transfer case position sensor (1) in the front case (2). Tighten sensor to 20-34 N·m (15-25 ft. lbs.) torque.


4. Install new seal washer (1) on front output shaft.
5. Lubricate companion flange hub with transmission fluid and install flange onto the front ouput shaft.
6. Install new flange nut onto front output shaft.
7. Tighten flange nut to 122-176 N·m (90-130 ft. lbs.) torque.

INSTALLATION




1. Mount transfer case on a transmission jack.
2. Secure transfer case to jack with chains.
3. Position transfer case under vehicle.
4. Align transfer case and transmission shafts and install transfer case on transmission.
5. Install and tighten transfer case attaching nuts to 35 N·m (26 ft. lbs.) torque.
6. Connect vent hose (3).


7. Connect transfer case position sensor connector (1) to sensor (2).
8. Align and connect propeller shafts. (Refer to 3 - DIFFERENTIAL & DRIVELINE/PROPELLER SHAFT/PROPELLER SHAFT - INSTALLATION) .


9. Connect shift cable (2) to transfer case range (1) lever.


10. Fill transfer case with correct fluid. Check transmission fluid level. Correct as necessary.
11. Install skid plate (1). (Refer to 13 - FRAME & BUMPERS/FRAME/TRANSFER CASE SKID PLATE - INSTALLATION)
12. Remove transmission jack and support stand.
13. Lower vehicle and verify transfer case shift operation.