Mp3023 Transfer Case - Service Information Jeep Grand Cherokee WK2

DESCRIPTION

The Select-Trac® II is the MP3023 two-speed, on-demand, active four-wheel drive transfer case that provides optimum traction for a wide range of conditions, while maximizing driver convenience. When operating in 4WD Auto mode, this sophisticated system anticipates and prevents slip by redirecting torque as necessary.

For added traction capability when traversing steep grades, rough terrain or extremely poor traction surfaces, the transfer case includes a 4WD Low mode. This second speed gear multiplies engine torque 2.72 times and locks the clutch pack for maximum traction.

Electric shifting between 4WD AUTO and 4WD Low is effected with a console-mounted switch. A pushpin button is used to shift to Neutral mode.

The MP3023 transfer case provides the following benefits

1. Active, on-demand four-wheel drive requires no driver input.
2. Instantly anticipates slip and preemptively redirects torque as needed.
3. Vehicle stability under all conditions because torque is constantly being transferred.
4. 4WD Low operation mode provides an advantage over vehicles equipped with a single-speed all-wheel drive transfer case.
5. Electric shifting between 4WD Auto and 4WD Low provides smooth operation and improved NVH control compared to systems with mechanical linkage.
6. Enhanced traction and stability provided by the Traction Control and Electronic Stability Program (ESP) working in tandem with four-wheel-drive.
7. A robust design and sealing for reliability.
8. Maintenance-free.
9. A neutral mode permits flat towing.

OPERATING RANGES

Transfer case operating ranges are

1. Operating positions: 4WD Auto - N - 4WD Low.
2. 4WD Auto = Electronically controlled wet clutch for torque biasing.
3. N = Transfer case neutral for 4-wheel flat recreational towing.
4. 4WD Low = Low range (2.72:1) part time mode.

The 4WD Low range is for off road use only. It is not for use on hard surface roads unless the road surface is wet, slippery, or covered by ice and snow.

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

ACTIVE TRANSFER CASE CONTROLS

Controls for the MP3023 transfer case active clutch (torque biasing device) are located in the Drive Train Control Module (DTCM) and communicated on the Controller Area Network (CAN) C bus. The DTCM monitors multiple vehicle sensors to anticipate conditions which may result in wheel slip or reduced performance and preemptively adjusts torque split to front and rear axles as needed. The DTCM also compares wheel speeds at the front and rear axles to detect wheel slippage. A complete vehicle dynamics model, or algorithm, calculates slip at each tire for given vehicle-operating conditions. When wheel slip is detected, pressure applied to the transfer case clutch pack can be increased or decreased to apply increased torque to the axle with higher traction.

TRANSFER CASE MODES

The transfer case operates in active full-time four-wheel drive (4WD AUTO) unless the driver chooses 4WD Low, or Neutral.

ELECTRIC SHIFT MECHANISM

The electronically controlled wet clutch pack uses an electric motor to actuate an internal gear train, clutch cam, and low range barrel cam. The clutch cam actuates the clutch levers that apply normal force to the multi-disc wet clutch pack. The clutch discs are alternately splined to the front and rear drive shafts. When normal force is applied to this clutch pack, torque is transferred to equalize speed differences between front and rear axles.

Transfer of torque from one wheel to the other on an axle is accomplished by using Brake Traction Control. Under the right conditions the vehicle can be driven by just one wheel.

ELECTRONIC STABILITY PROGRAM (ESP)

Standard Electronic Stability Program (ESP) works with the four-wheel drive system to enhance traction and control through three new features: Hill Descent, Hill Start Assist and Trailer Sway Control.

TRANSFER CASE - MP3023

DIAGNOSIS CHART

SPECIFICATIONS

MP3023 FLUID

TORQUE

Scheme 29

Scheme 30

1. Shift transfer case into NEUTRAL.
2. Raise vehicle. NOTE: The air suspension system will auto-disable when lifted on a frame hoist, or when jacking one corner of the vehicle. The air suspension may attempt to change height slightly prior to switching to auto-disable. A manual disable is also available by pressing the "Up" and "Down" switches of the terrain select switch simultaneously for more that 5 seconds. The air suspension system will return to normal operation when the vehicle speed reaches 25 kph (15 mph).
3. Remove transfer case fill plug (1) and drain plug (2) to drain transfer case lubricant.
4. Support transmission (3) with jack stand.
5. Remove rear crossmember and skid plate, if equipped.
6. Remove the rear support cushion. CAUTION: Do not allow propeller shafts to hang at attached end. Damage to joint can result.
7. Disconnect front propeller shaft from transfer case at companion flange. Remove rear propeller shaft from vehicle. Refer to «SHAFT, DRIVE, FRONT , REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/driveshaft-universal-joints/#propeller-shaft__removal) and «SHAFT, DRIVE, REAR , REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/driveshaft-universal-joints/#propeller-shaft) .
8. Disconnect the transfer case shift motor and mode sensor electrical connector.
9. Disconnect transfer case vent hose.
10. Support transfer case (1) with transmission jack.
11. Secure transfer case to jack with chains.
12. Remove bolts (3) attaching transfer case to transmission (2).
13. Pull transfer case and jack rearward to disengage transfer case.
14. Remove transfer case from under vehicle.

Scheme 31

Note. If the transfer case assembly is being reconditioned (clutch/seal replacement) or replaced, it is necessary to perform the Quick Learn Procedure using the Scan Tool.

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

Scheme 38

Scheme 39

Scheme 40

Scheme 41

Scheme 42

Scheme 43

Scheme 44

Scheme 45

Scheme 46

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Scheme 58

Scheme 59

Scheme 60

Scheme 61

Scheme 62

Scheme 63

Scheme 64

Scheme 65

Scheme 66

Scheme 67

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

Scheme 75

Scheme 76

Scheme 77

Scheme 78

Scheme 79

1. Place the transfer case in a shallow pan and remove the fill and drain plugs to drain the remainder of the fluid.
2. Using Holder (special tool #C-3281, Holder, Flange) (1), remove the rear flange (2) nut.
3. Remove the rear output flange from the main shaft. If necessary, use a suitable 2 or 3 jaw puller to remove the output flange.
4. Remove encoder screws and the encoder from the transfer case.
5. Remove the shift shaft snap ring from the transfer case.
6. Remove shift motor bolts and the shift motor from the transfer case.
7. Remove the o-ring from the shift motor.
8. Using a suitable pry tool, remove shift motor seal from the transfer case.
9. Remove the worm shaft snap ring from the transfer case. CAUTION: Carefully unthread (rotate clockwise) the worm shaft to remove it from the transfer case. Failure to follow this caution may result in parts damage.
10. Remove the worm shaft from the transfer case NOTE: Some prying may be necessary to break the seal between the front and rear case. Use care to not damage the sealing surfaces.
11. Remove the bolts retaining the rear housing to the front housing and separate the housings.
12. Remove the output shaft thrust washer.
13. Remove the oil pump assembly.
14. Remove oil tube (1) from the oil pump and remove the o-ring (2).
15. Remove the pick-up magnet from the magnet pocket. NOTE: For ease of installation note the orientation of the worm shaft drive gear inner splines to the shift shaft outer splines.
16. Remove the worm drive gear. NOTE: For ease of installation note the orientation of the clutch cam inner splines to the shift shaft outer splines.
17. Remove the clutch cam.
18. Remove the clutch upper snap ring.
19. Remove the clutch shim.
20. Remove the thrust collar.
21. Remove the upper thrust bearing race.
22. Remove the upper thrust bearing.
23. Remove the upper shift lever.
24. Remove the shift lever balls.
25. Remove the lower shift lever.
26. Remove the lower thrust bearing.
27. Remove the lower thrust bearing race.
28. Remove the clutch apply piston. NOTE: For ease of installation note the assembly orientation of the 4 identical springs.
29. Remove the clutch return springs.
30. Remove the clutch pack.
31. Remove the inner clutch hub.
32. Remove the clutch drum thrust washer (1) and snap ring (2).
33. Remove the outer clutch drum from the mainshaft drive sprocket.
34. Remove the front drive sprocket, mainshaft drive sprocket and drive chain as one.
35. Remove the shift shaft spacer. NOTE: For ease of installation note the orientation of the barrel cam inner splines to the shift shaft outer splines.
36. Remove the barrel cam.
37. Remove the shift shaft.
38. Remove the main shaft from the transfer case.
39. Remove the detent assembly. NOTE: For ease of assembly note the orientation of the shift fork to the shift rail.
40. Remove the range shift rail assembly and range sleeve. Remove the rail, bracket, spring and washers from the shift fork.
41. Remove the retaining snap ring from the front output shaft.
42. Remove the front output shaft from the transfer case.
43. Using a suitable pry tool or a screw mounted in a slide hammer, remove the input gear seal. Remove the input gear snap ring.
44. Remove the input planetary gear assembly from the front housing.
45. Remove the snap-ring holding the input gear into the planetary gear.
46. Remove the lock plate from the input and planetary gear assembly.
47. Remove the thrust washer from the input and planetary gear assembly.
48. Remove the input gear from the planetary gear.
49. Remove the tabbed thrust washer from the planetary gear.

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

Inspect the case for cracks, porous spots, worn bores, or damaged threads. Damaged threads can be repaired with Helicoil® thread inserts. However, the case will have to be replaced if it exhibits any type of damage or wear.

ASSEMBLY

Note. If the transfer case assembly is being reconditioned (clutch/seal replacement) or replaced, it is necessary to perform the Quick Learn Procedure using the Scan Tool.

Note. Lubricate all seals with MOPAR® ATF+4 prior to installation.

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

Scheme 85

Scheme 86

Scheme 87

Scheme 88

Scheme 89

Scheme 90

1. While holding the retaining ring tabs apart with suitable snap-ring pliers, remove the input shaft bearing (1) from the front case (2).
2. Transfer the retaining ring to the new housing, if necessary, and install the bearing into the front case.
3. Using a suitable pry tool or a screw mounted in a slide hammer, remove the front output shaft seal.
4. Using Installer (special tool #6061, Installer, Cup) inverted, and Handle (special tool #C-4171, Driver Handle, Universal), remove front output shaft bearing.
5. Start front output shaft bearing in case. Then seat bearing with Handle (special tool #C-4171, Driver Handle, Universal) (3) and Installer (special tool #C-4210, Installer, Seal) (2).
6. Install the front output shaft seal using Installer (special tool #6560, Installer, Bearing Cup).
7. Using a suitable pry tool or a screw mounted in a slide hammer, remove the rear output shaft seal.
8. Remove the rear output shaft bearing from the rear case using Installer (special tool #L-4408, Installer, Bearing) (2) inverted and Handle (special tool #C-4171, Driver Handle, Universal) (1).
9. Install the rear output shaft bearing into the rear case using Remover/Installer (special tool #6061, Installer, Cup) inverted and Handle (special tool #C-4171, Driver Handle, Universal).
10. Remove shift shaft bearing snap ring.
11. Remove shift shaft bearing using Handle (special tool #C-4171, Driver Handle, Universal) (1) and Installer / Remove (special tool #5066, Installer, Bushing) (2).
12. Install shift shaft bearing using Handle (special tool #C-4171, Driver Handle, Universal) and Installer / Remover (special tool #5066, Installer, Bushing) inverted.
13. Install shift shaft bearing snap ring.
14. Remove front output shaft rear bearing from housing using Puller (special tool #7794-A, Remover, Seal) (1) and Slide Hammer (special tool #C-637, Slide Hammer, Universal) (2).
15. Install front output shaft rear bearing in housing using Installer (special tool #6061, Installer, Cup) (2) inverted and Handle (special tool #C-4171, Driver Handle, Universal) (2).
16. Install the front output shaft flange (2) into the front housing (1).
17. Install the front output shaft snap ring.
18. Install the bottom thrust tabbed washer into the planetary gear.
19. Install the input gear into the planetary gear.
20. Install the thrust washer onto the input planetary gear assembly.
21. Install the lock plate onto the input planetary gear assembly.
22. Install the snap ring into the input planetary gear assembly.
23. Install the input planetary gear assembly into the front housing.
24. Install the input gear snap ring.
25. Using Installer (special tool #9672, Installer, Seal) (2) and Handle (special tool #C-4171, Driver Handle, Universal) (1), install a new input shaft seal.
26. Install the spring washers onto each side of the spring and install the spring assembly into the shift fork.
27. Install the shift bracket over the spring washers and onto the shift fork.
28. Install the range sleeve into the shift fork.
29. Install the range shift assembly and range sleeve.
30. Install the detent assembly.
31. Install the mainshaft into the transfer case.
32. Install the shift shaft. NOTE: Before installing the barrel cam, note the orientation of the inner barrel cam splines to the outer splines on the shift shaft.
33. Install the barrel cam.
34. Install the shift shaft spacer. NOTE: There is a blue link on one side of the chain. This blue link MUST be installed facing upward.
35. Install the front drive sprocket, mainshaft drive sprocket and drive chain as one.
36. Install the outer clutch drum onto the mainshaft drive sprocket.
37. Install the clutch drum snap ring (2) and thrust washer (1).
38. Install the inner clutch hub.
39. Starting with a friction disc and ending with a friction disc, install the clutch pack.
40. Install the clutch return springs.
41. Install the clutch apply piston with the lettering up and the stepped face down.
42. Install the lower bearing race with the race fitting into the grove in the reaction plate.
43. Install the lower bearing.
44. Install the lower shift lever.
45. Install the shift lever balls into their pockets.
46. Install the upper shift lever.
47. Install the upper thrust bearing.
48. Install the upper bearing race.
49. Install the thrust collar.
50. Install the clutch shim.
51. Install clutch upper snap ring. NOTE: The clutch cam has the word "FRONT" stamped into. This identifies the orientation of the clutch cam to the front of the transfer case. Before installing the clutch cam, note the orientation of the clutch cam inner splines to the outer splines on the shift shaft. Install it such that the roller falls into low point of clutch cam.
52. Install the clutch cam. NOTE: Before installing the worm drive gear, note the orientation of the worm drive gear inner splines to the outer splines on the shift shaft.
53. Install the worm drive gear.
54. Install the magnet into the magnet pocket. 1 - OIL TUBE 2 - O-RING SEAL
55. Install a new o-ring (2) onto the oil pump tube (1).
56. Lubricate the oil tube o-ring with MOPAR® ATF+4 and install the tube into the oil pump.
57. Install the oil pump assembly.
58. install the output shaft thrust washer. NOTE: Do not use excessive amount of sealer as excess could be displaced into the oil pump. Keep sealer bead width to maximum of 3 mm (1/8 inch).
59. Apply bead of Mopar® Gasket Maker, or equivalent, to one of the mating surfaces of the front or rear housing.
60. Install the rear housing onto the front housing. Install the housing bolts. Tighten housing bolts in a crisscross pattern to 27 N.m (20 ft.lbs.). CAUTION: Carefully align and thread (rotate counterclockwise) the worm shaft to install it into the transfer case. Failure to follow this caution may result in parts damage.
61. Install the worm shaft into the transfer case. NOTE: It may be necessary to apply slight inward pressure on the worm shaft to seat the snap ring.
62. Install the worm shaft snap ring.
63. Using a suitable installer, install the shift motor seal.
64. Install a new o-ring onto the shift motor. NOTE: Note the orientation of the shift motor shaft to the worm gear shaft.
65. Install the shift motor onto the transfer case. Install the shift motor bolts. Tighten the shift motor bolts to 13 N.m (9 ft. lbs.). NOTE: It may be necessary to pull out on the shift shaft to properly seat the shift shaft snap ring.
66. Install the shift shaft snap ring.
67. Align arrow (1) on the encoder shaft with alignment mark (2) prior to installing the encoder. NOTE: Before installing the encoder onto the transfer case, be certain to align the encoder shaft to the shift shaft and the dowel on the encoder to the hole in the case accordingly.
68. Install the encoder onto the rear transfer case housing. Install the encoder screws. Tighten the screws to 5-8 N.m (44-71 in.lbs.).
69. Using a suitable pry tool or a screw mounted in a slide hammer, remove the rear cover seal.
70. Using Installer (special tool #C-4210, Installer, Seal) (2) and Handle (special tool #C-4171, Driver Handle, Universal) (1), install the rear cover seal.
71. Install the companion flange onto the mainshaft.
72. Using Holder (special tool #C-3281, Holder, Flange) (1), install the rear output flange (2) nut. Tighten the nut to 122-176 N.m (90-130 ft.lbs.).

INSTALLATION

1. Mount transfer case (1) on a transmission jack.
2. Secure transfer case to jack with chains.
3. Position transfer case under vehicle.
4. Align transfer case (1) and transmission (2) shafts and install transfer case onto transmission.
5. Install and tighten transfer case attaching bolts (3) to 41-49 N.m (30-36 ft. lbs.) torque.
6. Connect the transfer case vent hose to the transfer case.
7. Install the rear support cushion.
8. Install rear crossmember and skid plate, if equipped.
9. Remove transmission jack and support stand.
10. Connect front propeller shaft and install rear propeller shaft. Refer to «SHAFT, DRIVE, FRONT , INSTALLATION»(/jeep/grand-cherokee/wk2-2010-2013/remont/driveshaft-universal-joints/#propeller-shaft__installation) and «SHAFT, DRIVE, REAR , INSTALLATION»(/jeep/grand-cherokee/wk2-2010-2013/remont/driveshaft-universal-joints/#propeller-shaft) .
11. Install the transfer case drain plug (2). Tighten plug to 20-34 N.m (15-25 ft. lbs.)
12. Fill transfer case with correct fluid. Check transmission fluid level. Refer to «STANDARD PROCEDURE - FLUID DRAIN/REFILL»(/jeep/grand-cherokee/wk2-2010-2013/remont/transfer-case/#mp3023-transfer-case-service-information__standard-procedure-fluid-drainrefill) . . Correct as necessary.
13. Install the transfer case fill plug (1). Tighten the plug to 20-34 N.m (15-25 ft.lbs.).
14. Connect the shift motor and encoder electrical connectors.
15. Lower vehicle and verify transfer case shift operation.

Note. The air suspension system will auto-disable when lifted on a frame hoist, or when jacking one corner of the vehicle. The air suspension may attempt to change height slightly prior to switching to auto-disable. A manual disable is also available by pressing the "Up" and "Down" switches of the terrain select switch simultaneously for more that 5 seconds. The air suspension system will return to normal operation when the vehicle speed reaches 25 kph (15 mph).

SPECIAL TOOLS

5066 - Installer, Bushing (Originally Shipped In Kit Number(s) 9975.) 6061 - Installer, Cup (Originally Shipped In Kit Number(s) 6303, 6822.) 6560 - Installer, Bearing Cup (Originally Shipped In Kit Number(s) 6671, 9698.) 7794-A - Remover, Seal (Originally Shipped In Kit Number(s) 6645.) 9672 - Installer, Seal (Originally Shipped In Kit Number(s) 9696, 9697, 9698.) C-3281 - Holder, Flange (Originally Shipped In Kit Number(s) 9202, 9202A-CAN, 9202CC, 9299, 9299CC, 9299CC, 9300A-CAN.) C-4171 - Driver Handle, Universal (Originally Shipped In Kit Number(s) 9202, 9202A-CAN, 9202CC, 9299, 9299CC, 9299CC, 9300A-CAN.) C-4210 - Installer, Seal (Originally Shipped In Kit Number(s) 9975.) C-637 - Slide Hammer, Universal (Originally Shipped In Kit Number(s) 9202.) L-4408 - Installer, Bearing

Scheme 91

Scheme 92

Scheme 93

Note. If the transfer case assembly is being reconditioned (clutch/seal replacement) or replaced, it is necessary to perform the Quick Learn Procedure using the Scan Tool.

1. Remove the clutch upper snap ring.
2. Remove the clutch shim.
3. Remove the thrust collar.
4. Remove the upper thrust bearing race.
5. Remove the upper thrust bearing.
6. Remove the upper shift lever.
7. Remove the shift lever balls.
8. Remove the lower shift lever.
9. Remove the lower thrust bearing.
10. Remove the lower bearing race.
11. Remove the clutch apply piston. NOTE: For ease of installation note the assembly orientation of the 4 identical springs.
12. Remove the clutch return springs. NOTE: For ease of installation note the assembly configuration of the clutch plates and friction discs.
13. Remove the clutch pack.
14. Remove the inner clutch hub.
15. Remove the clutch hub thrust washer (1) and snap ring (2).
16. Remove the outer clutch drum from the main shaft and drive sprocket.

Note. If the transfer case assembly is being reconditioned (clutch/seal replacement) or replaced, it is necessary to perform the Quick Learn Procedure using the Scan Tool.

1. Install the outer clutch drum onto the main shaft and drive sprocket.
2. Install the clutch hub snap ring (2) and thrust washer (1).
3. Install the inner clutch hub.
4. Starting with friction disc and ending with a friction disc, install the clutch pack. NOTE: The four identical springs must be installed in the orientation shown in illustration.
5. Install the clutch return springs.
6. Install the clutch apply piston with the lettering up and the stepped face down.
7. Install the lower thrust bearing race.
8. Install the lower thrust bearing.
9. Install the lower shift lever.
10. Install the shift lever balls into their pockets.
11. Install the upper shift lever.
12. Install the upper thrust bearing.
13. Install the upper thrust bearing race.
14. Install the thrust collar.
15. Install the clutch shim.
16. Install the clutch upper snap ring.

STANDARD PROCEDURE - FLUID DRAIN/REFILL

The fill and drain plugs are both in the rear case.

1. Raise vehicle. Ensure that the vehicle is level on the hoist. NOTE: The air suspension system will auto-disable when lifted on a frame hoist, or when jacking one corner of the vehicle. The air suspension may attempt to change height slightly prior to switching to auto-disable. A manual disable is also available by pressing the "Up" and "Down" switches of the terrain select switch simultaneously for more that 5 seconds. The air suspension system will return to normal operation when the vehicle speed reaches 25 kph (15 mph).
2. Position drain pan under transfer case.
3. Remove fill plug (1) and drain plug (2) and drain lubricant completely.
4. Install drain plug (2) and tighten plug to 27 N.m (20 ft. lbs.).
5. Fill transfer case to bottom edge of fill plug opening with MOPAR® ATF+4
6. Install and tighten fill plug (1) and tighten plug to 27 N.m (20 ft. lbs.).
7. Lower vehicle.

Scheme 94

The shift motor (3) is an electromechanical device consisting of a DC permanent magnet motor and a position holding brake. The shift motors' overall function is to move and lock a gear that moves the range fork and clutch lever found in the transfer case. This allows the transfer case to be shifted electrically to multiple operating positions (4WD AUTO and 4WD LOW. The operating current of the shift motor under stall conditions is 30 amps maximum at 72° F with 13.5 volts, at the motor leads.

OPERATION

Shifting in the transfer case occurs when a Pulse Width Modulated (PWM) voltage is supplied to the shift motor (3) by the Drive Train Control Module (DTCM). A linear analog position sensor (Encoder) (2) located on the rear transfer case housing, provides the DTCM with the motors' angular, rotational position. With this information, the DTCM continuously knows the motors' position, and therefore allows it to accurately control the motors' operation, including voltage polarity which is used to control motor direction.

The electronically controlled wet clutch pack uses an electric motor to actuate an internal gear train, clutch cam, and low range barrel cam. The clutch cam actuates the clutch levers that apply normal force to the multi-disc wet clutch pack. The clutch disks are alternately splined to the front and rear outputs. When normal force is applied to this clutch pack, torque is transferred to equalize speed differences between front and rear axles.

REMOVAL

Note. New shift motor assemblies are shipped in the NEUTRAL position. If a new shift motor assembly must be installed, it will be necessary to shift the transfer case to the NEUTRAL position prior to motor installation.

1. Disengage the wiring harness electrical connector from the shift motor.
2. Remove the bolts holding the shift motor onto the transfer case.
3. Remove the shift motor from the transfer case.
4. Remove the o-ring seal from the shift motor.

Note. Before installing the shift motor onto the transfer case, make certain that the shift motor shaft aligns with the transfer case worm shaft accordingly.

1. Install a NEW shift motor o-ring seal onto the shift motor.
2. Install the shift motor onto the transfer case.
3. Install the shift motor bolts. Tighten the shift motor bolts to 13 N.m (9 ft. lbs.).
4. Install the electrical wiring harness connector onto the shift motor.

1. Remove the transfer case from the vehicle. Refer to «REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/transfer-case/#mp3023-transfer-case-service-information__removal) .
2. Remove the front input shaft seal with a suitable pry tool or a screw mounted in a slide hammer.

Note. Lubricate all seals with MOPAR® ATF+4 prior to installation.

1. Using Installer (special tool #9672, Installer, Seal) (2) and Handle (special tool #C-4171, Driver Handle, Universal) (1), install a new input shaft seal.
2. Install the transfer case into the vehicle. Refer to «INSTALLATION»(/jeep/grand-cherokee/wk2-2010-2013/remont/transfer-case/#mp3023-transfer-case-service-information__installation) .
3. Check the transfer case fluid. Correct as necessary. Refer to «STANDARD PROCEDURE - FLUID DRAIN/REFILL»(/jeep/grand-cherokee/wk2-2010-2013/remont/transfer-case/#mp3023-transfer-case-service-information__standard-procedure-fluid-drainrefill) . .

The front output shaft seal and wear sleeve cannot be serviced in the vehicle. The transfer case must be disassembled to remove the front output shaft assembly and seal.

1. Remove the rear propeller shaft. Refer to «SHAFT, DRIVE, REAR , REMOVAL»(/jeep/grand-cherokee/wk2-2010-2013/remont/driveshaft-universal-joints/#propeller-shaft) .
2. Using Holder (special tool #C-3281, Holder, Flange) (1), remove the rear companion flange (2) nut.
3. Remove the rear output shaft flange from the output shaft. If necessary, use a suitable 2 or 3 jaw puller to remove the output shaft flange.
4. Remove the rear output shaft seal with a suitable pry tool or a screw mounted in a slide hammer.
5. Remove the rear cover bolts and the rear cover from the transfer case.

Note. Lubricate all seals with MOPAR® ATF+4 prior to installation.

1. Install a new rear output shaft seal into the rear cover with Driver Handle (special tool #C-4171, Driver Handle, Universal) and inverted Installer (special tool #C-4210, Installer, Seal).
2. Install the rear output shaft flange onto the output shaft.
3. Using Holder (special tool #C-3281, Holder, Flange) (1), install the rear companion flange (2) nut. Tighten the nut to 122-176 N.m (90-130 ft.lbs.).
4. Install the rear propeller shaft. Refer to «SHAFT, DRIVE, REAR , INSTALLATION»(/jeep/grand-cherokee/wk2-2010-2013/remont/driveshaft-universal-joints/#propeller-shaft) .
5. Check the transfer case fluid level. Refer to «STANDARD PROCEDURE - FLUID DRAIN/REFILL»(/jeep/grand-cherokee/wk2-2010-2013/remont/transfer-case/#mp3023-transfer-case-service-information__standard-procedure-fluid-drainrefill) . . Correct as necessary.

The transfer case Encoder (2) provides the Drive Train Control Module (DTCM) feedback about the position of the transfer case. The sensor consists of a linear analog position sensor that converts the motor output shaft position into a DC signal. The sensor may rotate a full 360 degrees. The DTCM must supply 5VDC (+/- 0.5v) to the sensor whenever the DTCM is not in sleep mode and monitors the shift motor position. The sensor position is monitored when the ignition is in the RUN position and for 10 seconds after the ignition is shifted to the OFF position. The sensor is mechanically linked to the shaft of the cam which allows the transfer case to shift. The mode sensor will draw less than 20 mA of current during operation.

During normal vehicle operation, the DTCM monitors the mode sensor outputs at least every 2 milliseconds when the shift motor is stationary or active. The mode sensor position will be considered invalid by the DTCM if the voltage is greater than 4.75 V or if it is less than 0.25 V.

Note. All the parameter voltages referred to in the following information are calibrated items in the controller software and are subject to change.

The DTCM shall consider Transfer Case position based on the MODE SENSOR VOLTAGES table listed below

MODE SENSOR VOLTAGES

1. Remove the wiring harness electrical connector from the encoder.
2. Remove the screws securing the encoder to the rear transfer case housing.
3. Remove the encoder from the transfer case.

1. Align arrow (1) on the encoder shaft with alignment mark (2) prior to installing the encoder. NOTE: Before installing the encoder onto the transfer case, be certain to align the encoder shaft to the shift shaft and the dowel on the encoder to the hole in the case accordingly.
2. Install the encoder onto the rear transfer case housing.
3. Install the encoder screws. Tighten the screws to 5-8 N.m (44-71 in.lbs.).
4. Install the electrical wiring harness connector onto the encoder.

Scheme 95

Electric shifting between 4WD Auto and 4WD Low is accomplished with a console-mounted switch. A pushpin button is used to shift to Neutral mode.

1. Hill Decent Control (1).
2. 4WD Low (2).
3. Sport Terrain position (3).
4. Snow Terrain position (4).
5. Auto Terrain position (5).
6. Sand/Mud Terrain position (6).
7. Rock Terrain position (7).
8. Air Suspension Up (8) (if equipped).
9. Air Suspension Down (9) (if equipped).
10. Terrain selector control knob (10).
11. Neutral Position (11).

See also:
• SHAFT, DRIVE, FRONT , REMOVAL
• SHAFT, DRIVE, REAR , REMOVAL
• SHAFT, DRIVE, FRONT , INSTALLATION
• STANDARD PROCEDURE - FLUID DRAIN/REFILL
• REMOVAL
• INSTALLATION