Transfer Case - NV271: Other Dodge Pickup R2500

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(tm) 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.

INPUT GEAR AND PLANETARY CARRIER

Check the teeth on the gear (Scheme 169) 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.

Scheme 169

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.

SHIFT FORKS/HUBS/SLEEVES

Check condition of the shift forks and mode fork shift rail (Scheme 170) Minor nicks on the shift rail can be smoothed with 320-400 grit emery cloth.

Scheme 170

Inspect the shift fork wear pads (Scheme 171) 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.

Scheme 171

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 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 (Scheme 172)

Scheme 172

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(tm) 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(tm) 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 173

Scheme 174

Scheme 175

Scheme 176

Scheme 177

Scheme 178

Scheme 179

Scheme 180

Scheme 181

Scheme 182

Scheme 183

Scheme 184

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 Installer 6953 and Handle C-4171 (Scheme 173)
3. Install the input shaft bearing into the front case half with Installer 8151 inverted on Handle C-4171 (Scheme 174)
4. Install the input shaft bearing snap-ring into the front case half with suitable snap-ring pliers.
5. Remove the front output shaft front bearing snap-ring from the front case half.
6. Using Installer 6953 and Handle C-4171 (Scheme 175), remove the front output shaft front bearing.
7. Start front output shaft front bearing in case. Then seat bearing with Installer 8891 (Scheme 176)
8. Install front output shaft bearing retaining ring.
9. Remove input gear pilot bearing by inserting a suitably sized drift into the splined end of the input gear and driving the bearing out with the drift and a hammer (Scheme 177)
10. Install new pilot bearing with Installer 9035.
11. Remove the front output shaft rear bearing with the screw and jaws from Remover L-4454 and Cup 8148 (Scheme 178)
12. Install new bearing with Tool Handle C-4171 and Installer 8128 (Scheme 179) The bearing bore is chamfered at the top. Install the bearing so it is flush with the lower edge of this chamfer (Scheme 180)
13. Remove seal from oil pump with suitable pry tool.
14. Install new seal in oil pump with Installer 7888 (Scheme 181)
15. Remove the rear output shaft bearing snap-ring (Scheme 182) from the rear case half.
16. Remove the rear output shaft bearing from the rear case using Installer 7888 (Scheme 183)
17. Install the rear output shaft bearing (Scheme 184) into the rear case using Installer 8152 and Handle C-4171.
18. Install the rear output shaft bearing snap-ring into the rear case half.

Scheme 185

Scheme 186

Scheme 187

Scheme 188

Scheme 189

Scheme 190

Scheme 191

1. Lubricate gears and thrust washers with recommended transmission fluid.
2. Install bottom thrust washer (Scheme 185) in low range gear planetary. Be sure washer tabs are properly aligned in gear notches.
3. Install input gear in low range gear (Scheme 186) Be sure input gear is fully seated.
4. Install remaining thrust washer (Scheme 187) in low range gear and on top of input gear.
5. Install retainer (Scheme 188) on input gear and install snap-ring (Scheme 189)
6. Align and install low range/input gear assembly in front case (Scheme 190) 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 to hold input/low range gear into front bearing (Scheme 191)
8. Install a new input gear seal using Installer 8841 and Handle C-4171.
9. Install a new input gear oil seal with Installer 9036 and Handle C-4171.

Scheme 192

Scheme 193

Scheme 194

Scheme 195

Scheme 196

Scheme 197

Scheme 198

Scheme 199

Scheme 200

Scheme 201

Scheme 202

Scheme 203

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 (Scheme 192) onto the mainshaft.
3. Install the mode hub (Scheme 193) onto the main-shaft.
4. Install the mode hub retaining ring (Scheme 194) onto the mainshaft.
5. Install the clutch gear (Scheme 195) onto the output shaft. Verify that the pointed ends of the clutch gear teeth are pointing to the front of the mainshaft.
6. Lubricate sector shaft with transmission fluid and install shift sector in case (Scheme 196) Position slot in sector so it will be aligned with shift fork pin when shift forks are installed.
7. Apply Loctite(tm) 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 9033 to 27-34 N.m (20-25 ft.lbs.).
8. Assemble and install range fork and hub (Scheme 197) 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.
10. Install mode fork and shift rail onto the mode sleeve.
11. Install the mode fork, sleeve, and shift rail into the transfer case (Scheme 198)
12. Install mainshaft into the transfer case (Scheme 199) Guide mainshaft through the mode and range sleeves and into the input gear.
13. Install the transfer case position sensor (Scheme 200) Tighten the sensor to 20-34 N.m (15-25 ft. lbs.) torque.
14. Install manual shift lever and spacer onto sector shaft (Scheme 201)
15. Install washer and nut on sector shaft to secure shift lever. Apply 1-2 drops Mopar(R) Lock N' Seal, or equivalent, to nut threads before installation. Then tighten nut to 27-34 N.m (20-25 ft. lbs.) torque.
16. Install new o-ring on detent plug (Scheme 202)
17. Install detent plunger, spring, and plug (Scheme 203) Tighten the plug to 16-25 N.m (12-18 ft. lbs.).

Scheme 204

Scheme 205

Scheme 206

Scheme 207

Scheme 208

Scheme 209

Scheme 210

1. Install the front output shaft (Scheme 204) into the front output shaft front bearing.
2. Install the front output shaft bearing inner snap-ring (Scheme 205) onto the output shaft.
3. Install the new front output shaft seal with Installer MB991168A
4. Insert front drive sprocket in drive chain.
5. Install drive chain around rear drive sprocket.
6. Position rear drive sprocket (Scheme 206) over the output shaft and lower the sprocket and chain assembly until the front sprocket is positioned over the front output shaft.
7. Align the splines in the sprockets to the splines on the output shafts and install the sprockets onto the output shafts.
8. Install front sprocket retaining ring (Scheme 207)
9. Install rear sprocket retaining ring (Scheme 208)
10. Install spring onto shift rail (Scheme 209)
11. Insert magnet in front case pocket (Scheme 210)

Scheme 211

Scheme 212

Scheme 213

1. Install the oil pick-up tube and screen into the rear case half.
2. Apply bead of Mopar(R) 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 (Scheme 211) Verify that the case alignment dowels correctly seat into their mating recesses.
4. Install 4-5 rear case-to front case bolts (Scheme 212) 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.
5. Tighten bolts to 27-34 N.m (20-25 ft. lbs.)
6. Install rear output bearing inner snap-ring (Scheme 213) to output shaft.

Scheme 214

Scheme 215

Scheme 216

Scheme 217

Scheme 218

Scheme 219

1. Install the oil pump (Scheme 214) onto the output shaft.
2. Engage the oil pump pick-up tube (Scheme 215) into the oil pump. Verify that the pick-up tube o-ring is on the tube and is correctly installed to the oil pump.
3. Apply bead of Mopar(R) 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 (Scheme 216) onto the rear case half.
5. Install rear extension bolts (Scheme 217) Tighten the bolts to 27-34 N.m (20-25 ft.lbs.).
6. Install the extension housing boot and seal assembly with Installer 9037 and Handle C-4171 (Scheme 218)
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 over the bolts and against the companion flange (Scheme 219)
10. Install a new front companion flange nut. Tighten the companion flange nut to 176-271 N.m (130-200 ft.lbs.).