NV271 Transfer Case - Service Information: Other RAM Pickup 2500

OPERATING RANGE

Transfer case operating ranges are

1. 2H (2-wheel drive).
2. 4H (4-wheel drive).
3. 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

The transfer case is operated by an adjustable floor mounted shift linkage. The transfer case shift lever is directly attached to the shift sector. The sector operates the range and mode forks within the transfer case.

A straight line shift pattern is used with a NEUTRAL detent. Lever range positions are imprinted in the shift knob.

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.

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.

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.

Scheme 112

Check the teeth on the gear (6). (Scheme 112) 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. Check the pinion gear thrust washers on the pinon pins for 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.

Scheme 113

Check condition of the shift forks and mode fork shift rail (2). (Scheme 113) Minor nicks on the shift rail can be smoothed with 320-400 grit emery cloth.

Scheme 114

Inspect the shift fork wear pads (3). (Scheme 114) 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.

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.

Scheme 115

Inspect annulus gear (2) condition carefully. The gear is only serviced as part of the front case (1). 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 (2) (Scheme 115)

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.

Scheme 116

Scheme 117

Scheme 118

Scheme 119

Scheme 120

Scheme 121

Scheme 122

Scheme 123

Scheme 124

Scheme 125

Scheme 126

Scheme 127

1. Remove the input shaft bearing snap-ring from the front case half with suitable snap-ring pliers.
2. Remove the input shaft bearing from the front case half with Bearing Installer (special tool #6953, Remover/Installer, Bearing) (3) and Universal Handle (special tool #C-4171, Driver Handle, Universal) (2). (Scheme 116) 1 - FRONT CASE HALF 2 - UNIVERSAL HANDLE C-4171 3 - BEARING CUP INSTALLER 8151 (INVERTED)
3. Install the input shaft bearing into the front case half with Bearing Cup Installer (special tool #8151, Installer, Bearing Cup) (3) inverted on Universal Handle (special tool #C-4171, Driver Handle, Universal) (2). (Scheme 117)
4. Install the input shaft bearing snap-ring into the front case half with suitable snap-ring pliers. 1 - FRONT CASE HALF 2 - UNIVERSAL HANDLE C-4171 3 - BEARING INSTALLER 6953
5. Remove the front output shaft front bearing snap-ring from the front case half.
6. Using Bearing Installer (special tool #6953, Remover/Installer, Bearing) (3) and Universal Handle (special tool #C-4171, Driver Handle, Universal) (2), remove the front output shaft front bearing. (Scheme 118) 1 - FRONT CASE HALF 2 - SEAL INSTALLER 8891
7. Start front output shaft front bearing in front case (1). Then seat bearing with Seal Installer (special tool #8891, Installer, Seal) (2). (Scheme 119)
8. Install front output shaft bearing retaining ring. 1 - DRIFT 2 - INPUT GEAR
9. Remove input gear pilot bearing by inserting a suitably sized drift into the splined end of the input gear (2) and driving the bearing out with the drift (1) and a hammer. (Scheme 120)
10. Install new pilot bearing with Bearing Installer (special tool #9035, Installer, Bearing). 1 - REAR CASE 2 - REMOVER L-4454-1 AND L-4454-3 3 - CUP 8148
11. Remove the front output shaft rear bearing with the screw and jaws from Remover (special tool #L-4454A, Remover, Bearing Cup) (2) and Cup (special tool #8148, Cup) (3). (Scheme 121) 1 - REAR CASE HALF 2 - UNIVERSAL HANDLE C-4171 3 - BEARING INSTALLER 8128
12. Install new bearing with Universal Handle (special tool #C-4171, Driver Handle, Universal) (2) and Bearing Installer (special tool #8128, Installer, Bearing) (3). (Scheme 122) 1 - BEARING (SEATED) AT LOWER EDGE OF CHAMFER 2 - CHAMFER
13. The bearing bore is chamfered at the top. Install the bearing (1) so it is flush with the lower edge of this chamfer (2). (Scheme 123) 1 - HOUSING SEAL 2 - SEAL INSTALLER 7888 3 - OIL PUMP FEED HOUSING
14. Remove seal from oil pump with suitable pry tool.
15. Install new seal in oil pump (3) with Seal Installer (special tool #7888, Installer, Seal) (2). (Scheme 124) 1 - REAR CASE HALF 2 - REAR OUTPUT SHAFT BEARING 3 - SNAP-RING
16. Remove the rear output shaft bearing snap-ring (3) from the rear case half (1). (Scheme 125) 1 - REAR CASE HALF 2 - SEAL INSTALLER 7888
17. Remove the rear output shaft bearing from the rear case (1) using Seal Installer (special tool #7888, Installer, Seal) (2). (Scheme 126) 1 - REAR CASE HALF 2 - UNIVERSAL HANDLE C-4171 3 - SEAL INSTALLER 8152
18. Install the rear output shaft bearing into the rear case (1) using Seal Installer (special tool #8152, Installer, Seal) (3) and Universal Handle (special tool #C-4171, Driver Handle, Universal) (2). (Scheme 127)
19. Install the rear output shaft bearing snap-ring into the rear case half.

INPUT AND PLANETARY GEAR

1. Lubricate gears and thrust washers with recommended transmission fluid.
2. Install bottom thrust washer (2) in low range gear planetary (1). see scheme 56 Be sure washer tabs are properly aligned in gear notches. 1 - INPUT GEAR 2 - LOW RANGE PLANETARY
3. Install input gear (1) in low range gear (2). see scheme 57 Be sure input gear is fully seated. 1 - INPUT GEAR 2 - THRUST PLATE
4. Install remaining thrust washer (2) in low range gear and on top of input gear (1). see scheme 58 1 - INPUT GEAR 2 - RETAINER
5. Install retainer (2) on input gear (1). see scheme 59 1 - INPUT GEAR 2 - RETAINING RING
6. Install snap-ring (2). see scheme 60 1 - FRONT CASE 2 - INPUT PLANETARY ASSEMBLY
7. Align and install low range/input gear assembly (2) in front case (1). see scheme 61 Be sure low range gear pinions are engaged in annulus gear and that input gear shaft is fully seated in front bearing. 1 - INPUT GEAR 2 - RETAINING RING
8. Install snap-ring (2) to hold input/low range gear (1) into front bearing. see scheme 62
9. Install a new input gear oil seal with Seal Installer (special tool #9036, Installer, Seal) and Universal Handle (special tool #C-4171, Driver Handle, Universal).

SHIFT FORKS AND MAINSHAFT

Scheme 128

Scheme 129

1. Lubricate mainshaft splines with recommended transmission fluid.
2. Coat the interior of the drive sprocket hub with ATF+4 and install the drive sprocket drive hub (2) onto the mainshaft (1). see scheme 63 1 - MAINSHAFT 2 - MODE HUB
3. Install the mode hub (2) onto the mainshaft (1). see scheme 64 1 - MAINSHAFT 2 - MODE HUB 3 - RETAINING RING
4. Install the mode hub retaining ring (3) onto the mainshaft (1). see scheme 65 1 - OUTPUT SHAFT 2 - CLUTCH GEAR 3 - MODE HUB
5. Install the clutch gear (2) onto the output shaft (1). see scheme 66 Verify that the pointed ends of the clutch gear teeth are pointing to the front of the mainshaft. 1 - SHIFT SECTOR
6. Lubricate sector shaft with transmission fluid and install shift sector (1) in case. see scheme 67 Position slot in sector so it will be aligned with shift fork pin when shift forks are installed.
7. Apply Loctite™ 242, or equivalent, to the threads of the sector support to replenish the factory applied patch. Install the shift sector support. Tighten the sector support with Socket (special tool #9033, Socket, Sector Support) to 27-34 N.m (20-25 ft. lbs.). 1 - RANGE HUB 2 - RANGE FORK
8. Assemble and install range fork (2) and hub (1). (Scheme 128) Be sure hub is properly seated in low range gear and engaged to the input gear.
9. Align and insert range fork pin in shift sector slot. 1 - SHIFT RAIL 2 - MODE FORK 3 - MODE SLEEVE
10. Install mode fork (2) and shift rail (1) onto the mode sleeve.
11. Install the mode fork (2), sleeve (3), and shift rail (1) into the transfer case. see scheme 69 1 - FRONT CASE HALF 2 - MAINSHAFT ASSEMBLY
12. Install mainshaft (2) into the transfer case (1). see scheme 70 Guide mainshaft through the mode and range sleeves and into the input gear. 1 - FRONT CASE 2 - POSITION SENSOR
13. Install the transfer case position sensor or switch (2). see scheme 71 Tighten the sensor or switch to 20-34 N.m (15-25 ft. lbs.) torque. 1 - SHIFT SECTOR 2 - SECTOR SUPPORT 3 - MANUAL SHIFT LEVER
14. Install manual shift lever (3)and spacer onto sector shaft (1). see scheme 72
15. Install washer and nut on sector shaft to secure shift lever. Apply 1-2 drops Mopar® Lock N' Seal, or equivalent, to nut threads before installation. Then tighten nut to 27-34 N.m (20-25 ft. lbs.) torque. 1 - O-RING 2 - DETENT PLUG
16. Install new o-ring (1) on detent plug (2). (Scheme 129) 1 - FRONT CASE HALF 2 - DETENT PLUG 3 - SPRING 4 - PLUNGER
17. Install detent plunger (4), spring (3), and plug (2). see scheme 74 Tighten the plug to 16-25 N.m (12-18 ft. lbs.).

FRONT OUTPUT SHAFT AND DRIVE CHAIN

Scheme 130

1. Install the front output shaft (2) into the front output shaft front bearing. see scheme 75 1 - FRONT CASE HALF 2 - SNAP-RING
2. Install the front output shaft bearing inner snap-ring (2) onto the output shaft. see scheme 76
3. Install the new front output shaft seal with Seal Installer (special tool #MB-991168-A, Installer, Seal) 1 - FRONT CASE HALF 2 - CHAIN 3 - DRIVE SPROCKETS
4. Insert front drive sprocket in drive chain.
5. Install drive chain around rear drive sprocket.
6. Position rear drive sprocket (3) over the output shaft and lower the sprocket and chain assembly until the front sprocket is positioned over the front output shaft. see scheme 77
7. Align the splines in the sprockets to the splines on the output shafts and install the sprockets onto the output shafts. 1 - FRONT OUTPUT SHAFT 2 - DRIVE SPROCKET 3 - RETAINING RING
8. Install front sprocket retaining ring (3). see scheme 78 1 - REAR OUTPUT SHAFT 2 - DRIVE SPROCKET 3 - RETAINING RING
9. Install rear sprocket retaining ring (3). see scheme 79 1 - SHIFT RAIL 2 - SPRING
10. Install spring (2) onto shift rail (1). see scheme 80 1 - MAGNET 2 - CASE POCKET
11. Insert magnet (1) in front case pocket (2). (Scheme 130)

REAR CASE

1. Install the oil pick-up tube and screen into the rear case half.
2. 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.
3. Align mainshaft with he rear output shaft bearing and align shift rail with bore in rear case. Then install rear case (2). see scheme 82 Verify that the case alignment dowels correctly seat into their mating recesses. 1 - FRONT CASE HALF 2 - REAR CASE HALF 3 - BOLTS
4. Install 4-5 rear case (2) -to- front case (1) bolts (3) to hold rear case in position. see scheme 83 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. 1 - OUTPUT SHAFT 2 - REAR CASE HALF 3 - SNAP-RING
5. Tighten bolts to 27-34 N.m (20-25 ft. lbs.).
6. Install rear output bearing inner snap-ring (3) to output shaft (1). see scheme 84

OIL PUMP AND REAR EXTENSION

Scheme 131

1. Install the oil pump (3) onto the output shaft (2). see scheme 85 1 - OIL PUMP 2 - OIL PICK-UP TUBE
2. Engage the oil pump pick-up tube (2) into the oil pump (1). see scheme 86 Verify that the pick-up tube o-ring is on the tube and is correctly installed to the oil pump. 1 - REAR CASE HALF 2 - EXTENSION HOUSING
3. 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.
4. Install extension housing (2) onto the rear case half (1). see scheme 87 1 - EXTENSION HOUSING 2 - BOLTS
5. Install rear extension bolts (2). see scheme 88 Tighten the bolts to 27-34 N.m (20-25 ft. lbs.). 1 - EXTENSION HOUSING 2 - UNIVERSAL HANDLE C-4171 3 - SEAL INSTALLER 9037
6. Install the extension housing boot and seal assembly with Seal Installer (special tool #9037, Installer, Dust Boot/Seal) (3) and Universal Handle (special tool #C-4171, Driver Handle, Universal) (2). (Scheme 131) 1 - YOKE HOLDER 6719 2 - BOLTS
7. Install the front companion flange onto the front output shaft.
8. Install two bolts 180° apart into the front output shaft companion flange.
9. Place holder (1) over the bolts (2) and against the companion flange. see scheme 90
10. Install a new front companion flange nut. Tighten the companion flange nut to 176-271 N.m (130-200 ft. lbs.).