Transmission and Transfer Case — part 3 of 4 — 1996 Jeep Grand Cherokee ZJ Service Manual
← Contents 1 2 3 4
Pages 1279–1338 · 60 pages · 7 words repaired
Replace the clutch spring and spring retainer if either is distorted, warped or broken.
Check the lug grooves in the clutch retainer. The steel plates should slide freely in the slots. Replace the retainer if the grooves are worn or damaged.
Check action of the check ball in the retainer (Fig. 351). The ball must move freely and not stick.
NOTE: Inspect the clutch retainer bushings carefully (Fig. 352). The retainer bushings are NOT serviceable. It will be necessary to replace the retainer if either bushing is scored, or worn.
Inspect the piston and retainer seal surfaces for nicks or scratches. Minor scratches can be removed with crocus cloth. However, replace the piston and/or retainer if the seal surfaces are seriously scored.
Location
REAR CLUTCH
Clean the clutch components (Fig. 353) with solvent and dry them with compressed air. Do not use rags or shop towels to dry any of the clutch parts. Lint from such materials will adhere to component surfaces and could restrict or block fluid passages after assembly.
Replace the clutch discs if warped, worn, scored, burned/charred, the lugs are damaged, or if the facing is flaking off. Replace the top and bottom pressure plates if scored, warped, or cracked. Be sure the driving lugs on the pressure and clutch plates are also in good condition. The lugs must not be bent, cracked or damaged in any way.
Replace the piston spring and wave spring if either part is distorted, warped or broken.
Check the lug grooves in the clutch retainer. The clutch and pressure plates should slide freely in the slots. Replace the retainer if the grooves are worn or damaged. Also check action of the check balls in the retainer and piston. Each check ball must move freely and not stick.
Replace the retainer bushing if worn, scored, or doubt exists about bushing condition.
Inspect the piston and retainer seal surfaces for nicks or scratches. Minor scratches can be removed with crocus cloth. However, replace the piston and/or retainer if the seal surfaces are seriously scored.
Check condition of the fiber thrust washer and metal output shaft thrust washer. Replace either washer if worn or damaged.
Check condition of the seal rings on the input shaft and clutch retainer hub. Replace the seal rings only if worn, distorted, or damaged. The input shaft front seal ring is teflon with chamfered ends. The rear ring is metal with interlocking ends.
Check the input shaft for wear, or damage. Replace the shaft if worn, scored or damaged in any way.
PLANETARY GEARTRAIN
Clean the planetary components in solvent and dry them with compressed air.
Check sun gear and driving shell condition (Fig. 354). Replace the gear if damaged or if the bushings are scored or worn. The bushings are not serviceable. Replace the driving shell if worn, cracked or damaged.
Replace planetary gear sets if gears, pinion pins, or carrier are damaged in any way. Replace the annulus gears and supports if either component is worn or damaged.
Inspect the geartrain spacers, thrust plates, snap rings, and thrust washers (Fig. 354). Replace any of these parts that are worn, distorted or damaged. Do not attempt to reuse these parts.
The planetary gear thrust washers are different sizes. The large diameter washers go on the front planetary and the smaller washers go on the rear planetary. All the washers have four locating tabs on them. These tabs fit in the holes or slots provided in each planetary gear.
Inspect the output shaft carefully. Pay particular attention to the machined bushing/bearing surfaces on the shaft and the governor valve shaft bore at the shaft rear.
Replace the output shaft if the machined surfaces are scored, pitted, or damaged in any way. Also replace the shaft if the splines are damaged, or exhibits cracks at any location (especially at the governor valve shaft bore).
The annulus gears can be removed from their supports if necessary. Just remove the snap rings and separate the two parts when replacement is necessary. In addition, the annulus gear bushings can be replaced if severely worn, or scored. However it is not necessary to replace the bushings if they only exhibit normal wear. Check bushing fit on the output shaft to be sure.
OVERDRIVE
Clean the geartrain (Fig. 355) and case components (Fig. 356) with solvent. Dry all parts except the bearings with compressed air. Allow bearings to air dry.
Do not use shop towels for wiping parts dry unless the towels are made from a lint-free material. A sufficient quantity of lint (from shop towels, cloths, rags, etc.) could plug the transmission filter and fluid passages.
Discard the old case gasket and seals. Do not attempt to salvage these parts. They are not reusable. Replace any of the overdrive unit snap rings if distorted or damaged.
Minor nicks or scratches on components can be smoothed with crocus cloth. However, do not attempt to reduce severe scoring on any components with abrasive materials. Replace severely scored components; do not try to salvage them.
Check condition of the park lock components and the overdrive gear case (Fig. 356).
Replace the case if cracked, scored, or damaged. Replace the park lock pawl, plug, or spring if worn or damaged. Be sure the knob at the end of the park lock rod is in good condition. Replace the rod if the knob is worn or the rod itself is bent or distorted. Do not attempt to straighten the rod.
Check the bushings in the overdrive case. Replace the bushings if severely scored or worn. Also replace the case seal if loose, distorted, or damaged.
Components
Examine the overdrive and direct clutch discs and plates (Fig. 355). Replace the discs if the facing is worn, severely scored, or burned and flaking off. Replace the clutch plates if worn, heavily scored, or cracked. Check the lugs on the clutch plates for wear. The plates should slide freely in the drum. Replace the plates or drum if binding occurs.
Check condition of the annulus gear, direct clutch hub, clutch drum and clutch spring (Fig. 355). Replace the gear, hub and drum if worn or damaged. Replace the spring if collapsed, distorted, or cracked. Be sure the splines and lugs on the gear, drum and hub are in good condition. The clutch plates and discs should slide freely in these components.
Inspect the thrust bearings and spring plate (Fig. 355). Replace the plate if worn or scored. Replace the bearings if rough, noisy, brinnelled, or worn.
Inspect the planetary gear assembly and the sun gear and bushings. If either the sun gear or the bushings are damaged, replace the gear and bushings as an assembly. The gear and bushings are not serviced separately.
The planetary carrier and pinions must be in good condition. Also be sure the pinion pins are secure and in good condition. Replace the carrier if worn or damaged.
Inspect the overrunning clutch and race. The race surface should be smooth and free of scores. Replace the overrunning clutch assembly or the race if either assembly is worn or damaged in any way.
Check the machined surfaces on the output shaft. These surfaces should be clean and smooth. Very minor nicks or scratches can be polished down with crocus cloth. Replace the shaft if worn, severely scored, or damaged in any way.
Inspect the output shaft bushings (Fig. 357). The small bushing is the intermediate shaft pilot bushing. The large bushing is the overrunning clutch hub bushing. Replace either bushing if scored, pitted, cracked, or worn. Remove the annulus gear from the output shaft if bushing replacement is required. This will provide more working room and make bushing replacement easier.
The bushings can be removed with “blind hole puller tools” such as Snap-On set CG40CB for small bushings and set CG46 for large bushings. New bushings can be installed with tools from an all purpose installer kit such as the Snap-On A257 bushing driver set.
ADJUSTMENTS
BRAKE TRANSMISSION SHIFT INTERLOCK
The park interlock cable is part of the brake/shift lever interlock system. Correct cable adjustment is important to proper interlock operation. The gear shift and park lock cables must both be correctly adjusted in order to shift out of Park.
Park Interlock Cable Adjustment Procedure
(1) Shift into Park position. (2) Turn ignition switch to Accessory position. Be sure ignition key cylinder is in Accessory position. Cable will not adjust correctly in any other position.
(3) Remove shift lever bezel and console screws. Raise bezel and console for access to park interlock cable.
(4) Pull cable lock button up to release cable (Fig. 358). (5) Pull cable forward. Then release cable and press lock button down until it snaps in place.
(6) Check cable adjustment. With shift lever in Park, ignition lock cylinder should rotate freely from Off to Lock. Cylinder should not rotate in any other shift lever position.
(7) Verify brake/transmission interlock operation: • Turn ignition lock cylinder to Run position. • Press and hold brake pedal down. Pedal must travel at least 12 mm (1/2 in.) to activate position switch and supply operating voltage to cable release solenoid.
• Press button on shift lever handle inward and verify that shift lever comes out of Park.
(8) Shift back into Park. It is not necessary to apply brakes to shift back into Park. Shift lever can be moved into Park with engine off, or running, and the lock cylinder in any position. All that is required, is that shift handle release button be pressed inward before moving shift lever.
TRANSMISSION THROTTLE VALVE CABLE ADJUSTMENT
The transmission throttle valve is operated by a cam on the throttle lever. The throttle lever is operated by an adjustable cable (Fig. 359). The cable is attached to an arm mounted on the throttle lever shaft. A lock button at the engine-end of the cable is provided for cable adjustment.
A correctly adjusted throttle valve cable will cause the throttle lever on the transmission to move simultaneously with the throttle body lever from the idle position. Proper adjustment will allow simultaneous movement without causing the transmission throttle lever to either move ahead of, or lag behind the lever on the throttle body.
Checking Throttle Valve Cable Adjustment
(1) Turn ignition key to OFF position. (2) Remove air cleaner. (3) Verify that lever on throttle body is at curb idle position. Then verify that transmission throttle lever (Fig. 360) is also at idle (fully forward) position.
(4) Slide cable off attachment stud on throttle body lever (Fig. 361).
(5) Compare position of cable end to attachment stud on throttle body lever (Fig. 361):
• Cable end and attachment stud should be aligned (or centered on one another) to within 1 mm (0.039 in.) in either direction.
• If cable end and attachment stud are misaligned (off center), cable will have to be adjusted as described in Throttle Valve Cable Adjustment procedure.
(6) Reconnect cable end to attachment stud. Then with aid of a helper, observe movement of transmission throttle lever and lever on throttle body.
• If both levers move simultaneously from idle to half-throttle and back to idle position, adjustment is correct.
• If transmission throttle lever moves ahead of, or lags behind throttle body lever, cable adjustment will be necessary. Or, if throttle body lever prevents transmission lever from returning to closed position, cable adjustment will be necessary.
Throttle Valve Cable Adjustment Procedure
(1) Turn ignition switch to OFF position. (2) Remove air cleaner if necessary. (3) Disconnect cable end from attachment stud. Carefully slide cable off stud. Do not pry or pull cable off.
(4) Verify that transmission throttle lever is in fully closed position. Then be sure lever on throttle body is at curb idle position.
(5) Press cable lock button inward to release cable (Fig. 361). Lock button only has to move about 2 mm (0.070 in.) to release cable in adjuster head.
(6) Center cable end on attachment stud to within 1 mm (0.039 in.) and release lock button. (7) Check cable adjustment. Be sure transmission throttle lever and lever on throttle body move simultaneously as described in cable adjustment checking procedure.
GEARSHIFT CABLE
Check adjustment by starting the engine in Park and Neutral. Adjustment is OK if the engine starts only in these positions. Adjustment is incorrect if the engine starts in one but not both positions. If the engine starts in any position other than Park or Neutral, or if the engine will not start at all, the park/ neutral position switch may be faulty.
Gearshift Adjustment Procedure
(1) Shift transmission into Park. (2) Raise vehicle. (3) Release cable adjuster clamp (at transmission end of cable) to unlock cable.
(4) Unsnap cable from cable mounting bracket on transmission (Fig. 362).
(5) Slide cable eyelet off transmission shift lever. (6) Verify transmission shift lever is in Park detent by moving lever fully rearward. Last rearward detent is Park position.
(7) Verify positive engagement of transmission park lock by attempting to rotate propeller shaft. Shaft will not rotate when park lock is engaged.
(8) Slide cable eyelt onto transmission shift lever. (9) Snap shift cable adjuster into mounting bracket on transmission.
(10) Lock shift cable by pressing cable adjuster clamp down until it snaps into place.
(11) Lower vehicle and check engine starting. Engine should start only in Park and Neutral.
FRONT BAND ADJUSTMENT
The front (kickdown) band adjusting screw is located on the left side of the transmission case above the manual valve and throttle valve levers.
(1) Raise vehicle. (2) Loosen band adjusting screw locknut (Fig. 363). Then back locknut off 3-5 turns. Be sure adjusting screw turns freely in case. Apply lubricant to screw threads if necessary.
(3) Tighten band adjusting screw to 8 N·m (72 in. lbs.) torque with Inch Pound Torque Wrench C-3380-A, a 3-in. extension and 5/16 socket.
CAUTION: If Adapter C-3705 is needed to reach the adjusting screw (Fig. 364), tighten the screw to only 5 N·m (47-50 in. lbs.) torque.
(4) Back off front band adjusting screw 2-7/8 turns.
(5) Hold adjuster screw in position and tighten locknut to 41 N·m (30 ft. lbs.) torque.
(6) Lower vehicle.
REAR BAND ADJUSTMENT
The transmission oil pan must be removed for access to the rear band adjusting screw.
(1) Raise vehicle.
(2) Remove transmission oil pan and drain fluid. (3) Loosen band adjusting screw locknut 5-6 turns. Be sure adjusting screw turns freely in lever.
(4) Tighten adjusting screw to 8 N·m (72 in. lbs.) torque (Fig. 365).
(5) Back off adjusting screw 2 turns. (6) Hold adjusting screw in place and tighten locknut to 34 N·m (25 ft. lbs.) torque.
(7) Position new gasket on oil pan and install pan on transmission. Tighten pan bolts to 17 N·m (13 ft. lbs.) torque.
(8) Lower vehicle and refill transmission with Mopar ATF Plus, Type 7176 fluid.
VALVE Body
CONTROL PRESSURE ADJUSTMENTS
There are two control pressure adjustments on the valve body;
• Line Pressure • Throttle Pressure Line and throttle pressures are interdependent because each affects shift quality and timing. As a result, both adjustments must be performed properly and in the correct sequence. Adjust line pressure first and throttle pressure last.
LINE PRESSURE ADJUSTMENT
Measure distance from the valve body to the inner edge of the adjusting screw with an accurate steel scale (Fig. 366).
Distance should be 33.4 mm (1-5/16 in.). If adjustment is required, turn the adjusting screw in, or out, to obtain required distance setting.
NOTE: The 33.4 mm (1-5/16 in.) setting is an approximate setting. Manufacturing tolerances may make it necessary to vary from this dimension to obtain desired pressure.
One complete turn of the adjusting screw changes line pressure approximately 1-2/3 psi (9 kPa).
Turning the adjusting screw counterclockwise increases pressure while turning the screw clockwise decreases pressure.
THROTTLE PRESSURE ADJUSTMENT
Insert Gauge Tool C-3763 between the throttle lever cam and the kickdown valve stem (Fig. 367).
Push the gauge tool inward to compress the kickdown valve against the spring and bottom the throttle valve.
Maintain pressure against kickdown valve spring. Turn throttle lever stop screw until the screw head touches throttle lever tang and the throttle lever cam touches gauge tool.
NOTE: The kickdown valve spring must be fully compressed and the kickdown valve completely bottomed to obtain correct adjustment.
SCHEMATICS AND DIAGRAMS
HYDRAULIC SCHEMATICS
HYDRAULIC FLOW IN PARK
HYDRAULIC FLOW IN NEUTRAL
HYDRAULIC FLOW IN REVERSE
HYDRAULIC FLOW IN DRIVE FIRST GEAR
HYDRAULIC FLOW IN DRIVE SECOND GEAR
HYDRAULIC FLOW IN DRIVE THIRD GEAR
HYDRAULIC FLOW IN DRIVE FOURTH GEAR (CONVERTER CLUTCH NOT APPLIED)
HYDRAULIC FLOW IN DRIVE FOURTH GEAR (CONVERTER CLUTCH APPLIED)
HYDRAULIC FLOW IN MANUAL LOW (1)
HYDRAULIC FLOW IN MANUAL SECOND (2)
HYDRAULIC FLOW DURING FULL THROTTLE 3–2 DOWNSHIFT (PASSING GEAR)
SPECIFICATIONS
TRANSMISSION
GENERAL
Component Metric Inch
Oil pump gear tip clearance
0.089-0.190 mm
0.004- 0.008 in.
Planetary end play 0.127-1.22 mm 0.005- 0.048 in.
Input shaft end play 0.56-2.31 mm 0.022- 0.091 in.
1.70-3.40mm 0.067- 0.134 in.
Clutch pack clearance/Front 4-disc.
Clutch pack clearance/Rear 4-disc.
0.81-1.40 mm 0.032- 0.055 in.
Overdrive clutch disc usage
4 discs
Direct clutch disc usage
8 discs
Front clutch spring usage
1 spring
Band adjustment from 72 in. lbs.
Front band Back off 2-7/8 turns
Rear band Back off 2 turns
Recommended fluid Mopar, ATF Plus type 7176
TORQUE
DESCRIPTION TORQUE Fitting, cooler line at trans. . . . . .18 N·m (13 ft. lbs.) Bolt, torque convertor . . . . . . . . . .31 N·m (23 ft. lbs.) Bolt/nut, crossmember . . . . . . . . .68 N·m (50 ft. lbs.) Bolt, driveplate to crankshaft . . . .75 N·m (55 ft. lbs.) Plug, front band reaction . . . . . . .17 N·m (13 ft. lbs.) Locknut, front band adj. . . . . . . . .34 N·m (25 ft. lbs.) Switch, park/neutral . . . . . . . . . . .34 N·m (25 ft. lbs.) Bolt, fluid pan. . . . . . . . . . . . . . . .17 N·m (13 ft. lbs.) Screws, fluid filter . . . . . . . . . . . . .4 N·m (35 in. lbs.) Bolt, oil pump . . . . . . . . . . . . . . . .20 N·m (15 ft. lbs.) Bolt, overrunning clutch cam . . . .17 N·m (13 ft. lbs.) Bolt, O/D to trans. . . . . . . . . . . . .34 N·m (25 ft. lbs.) Bolt, O/D piston retainer . . . . . . .17 N·m (13 ft. lbs.) Plug, pressure test port . . . . . . . .14 N·m (10 ft. lbs.) Bolt, reaction shaft support . . . . .20 N·m (15 ft. lbs.) Locknut, rear band . . . . . . . . . . . .41 N·m (30 ft. lbs.) Bolt. speedometer adapter . . . . . . .11 N·m (8 ft. lbs.) Bolt, valve body to case . . . . . . .12 N·m (100 in. lbs.) Sensor, trans speed. . . . . . . . . . . .27 N·m (20 ft. lbs.) Screw, solenoid wiring connector . .4 N·m (35 in. lbs.) Screw, solenoid to transfer plate . .4 N·m (35 in. lbs.)
THRUST WASHER/SPACER/SNAP RING DIMENSIONS
Front clutch thrust washer (reaction shaft support hub) 1.55 mm 0.061 in.
Rear clutch thrust washer (clutch retainer) 1.55 mm 0.061 in.
Intermediate shaft thrust plate (shaft hub pilot) 1.5-1.6 mm 0.060-0.063 in.
Output shaft thrust washer (rear clutch hub) Select fit to set end play
Rear clutch pack snap ring 1.5 mm 0.060 in.
Planetary geartrain snap ring (at front of output shaft) Select fit (three thicknesses avalible)
Overdrive piston thrust plate Thrust plate and spacer are select fit. Refer to size charts and selection procedures in Overdrive Unit D&A procedures Intermiediate shaft spacer
PRESSURE TEST
Overdrive clutch Fourth gear only Pressure should be 469-496 kPa (68-72 psi) with closed throttle and increase to 620-896 kPa (90-130 psi) at 1/2 to 3/4 throttle.
Line pressure (at accumulator)
Closed throttle 372-414 kPa (54-60 psi).
Front servo Third gear only No more than 21 kPa (3 psi) lower than line pressure.
Rear servo 1 range No more than 21 kPa (3 psi) lower than line pressure.
Governor D range closed throttle Pressure should respond smoothly to changes in mph and return to 0-7 kPa (0-1.5 psi) when stopped with transmission in D, 1, 2. Pressure above 7 kPa (1.5 psi) at stand still will prevent transmission from downshifting.
Component Metric Inch
1.95 mm 0.076 in.
2.45 mm 0.098 in.
R range 1103 kPa (160 psi) at idle, builds to 1862 kPa (270 psi) at 1600 rpm.
SPECIAL TOOLS
42/44 RE
Spring Compressor and Alignment Shaft—6227
Gauge Bar—6311
Snap-ring Plier—6823
Pressure Tester—7700
Extension Housing Pilot—C-3288-B
Pressure Gauge—C-3292
Pressure Gauge—C-3293SP
Dial Indicator—C-3339
Spring Compressor—C-3422-B
Puller, Slide Hammer—C-3752
Gauge, Throttle Setting—C-3763
Seal Installer—C-3860–A
Seal Puller—C-3861
Installer—C-3863-A
Snap-ring Plier—C-3915
Seal Installer—C-3972-A
Seal Puller—C-3981-B
Seal Remover—C-3985-B
Installer—C-3995-A
Universal Handle—C-4171
Seal Installer—C-4193-A
Remover/Installer—C-4470
Dial Caliper—C-4962
Bushing Remover/Intsaller Set—C-3887-B
Nut, Bushing Remover—SP-1191, From kit C-3887-B
Remover, Front Clutch Bushing—SP-3629, From kit
C-3887-B
Cup, Bushing Remover—SP-3633, From kit
C-3887-B
Installer, Oil Pump Bushing—SP-5118, From kit
C-3887-B
Remover, Reaction Shaft Bushing—SP-5301, From kit C-3887-B
Installer, Reaction Shaft Bushing—SP-5302, From kit C-3887-B
Installer, Front Clutch Bushing—SP-5511, From kit
C-3887-B
NV231 TRANSFER CASE
INDEX
GENERAL INFORMATION
GENERAL INFORMATION . . . . . . . . . . . . . . . . 147 RECOMMENDED LUBRICANT AND
FILL LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . 147 TRANSFER CASE IDENTIFICATION . . . . . . . . . 147 DIAGNOSIS AND TESTING
NV231 DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . 148 REMOVAL AND INSTALLATION
NV231 TRANSFER CASE . . . . . . . . . . . . . . . . . 149 SHIFT LEVER . . . . . . . . . . . . . . . . . . . . . . . . . . 149
GENERAL INFORMATION
GENERAL INFORMATION
The NV 231 is a part-time transfer case with a low range reduction gear mechanism.
The NV 231 has three operating ranges plus a Neutral position. The reduction gear mechanism consists of a planetary and annulus gear that provide a 2.7:1 reduction ratio when engaged. The annulus gear is fixed in the case; it does not rotate.
The input gear is splined to the transmission output shaft. It drives the mainshaft through the planetary gear and range hub. The front output shaft is operated by a drive chain that connects the shaft to a drive sprocket on the mainshaft. The drive sprocket is engaged/disengaged by the mode fork, which operates the mode sleeve and hub. The sleeve and hub are not equipped with a synchro mechanism for shifting.
The geartrain is mounted in two aluminum case halves attached with bolts. The mainshaft front and rear bearings are mounted in aluminum retainer housings bolted to the case halves.
OPERATING RANGES
NV 231 operating ranges are: • 2-wheel drive high (2H) • 4-wheel drive high (4H) • 4-wheel drive low (4L) Two-wheel drive range is for use on all road surfaces. The 4-wheel drive high and low ranges are not for use on paved roads. They are only recommended for off-road use on unpaved, low traction surfaces. The only time 4-wheel drive can be used on paved roads, is when the road surface is covered with snow or ice.
SHIFT MECHANISM
Operating ranges are selected with a floor mounted shift lever. The shift lever is connected to the transfer page page
DISASSEMBLY AND ASSEMBLY
NV231 TRANSFER CASE . . . . . . . . . . . . . . . . . 150 CLEANING AND INSPECTION
NV231 TRANSFER CASE . . . . . . . . . . . . . . . . . 163 ADJUSTMENTS
SHIFT LINKAGE ADJUSTMENT . . . . . . . . . . . . 167 SPECIFICATIONS
TORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 SPECIAL TOOLS
SPECIAL TOOLS—NV231 . . . . . . . . . . . . . . . . 168 case range lever by an adjustable linkage rod. A straight line shift pattern is used. Range positions are marked on the shifter bezel cover plate, or on the shift knob.
TRANSFER CASE IDENTIFICATION
A circular ID tag is attached to the rear case of each transfer case (Fig. 1). The ID 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. For example, a serial number of 7-10-95 would represent July 10, 1995.
RECOMMENDED LUBRICANT AND FILL LEVEL
Recommended lubricant for the NV 231 transfer case is Mopar Dexron II, or ATF Plus. Approximate lubricant fill capacity is 1.18 liters (2.2 pints).
The fill and drain plugs are both in the rear case (Fig. 1). Correct fill level is to the bottom edge of the fill plug hole. Be sure the vehicle is level to ensure an accurate fluid level check.
NV231 DIAGNOSIS
DIFFICULT TO SHIFT OR reduce speed to 3-4 km/h (2-3 mph) before
WILL NOT SHIFT INTO attempting to shift.
DESIRED RANGE
(2) If vehicle was operated for extended period in 4H (2) Stop vehicle, shift transmission to Neutral, shift
mode on dry paved surface, driveline torque load transfer case to 2H mode and operate vehicle in
may cause difficulty. 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
DEXRON II® or MOPAR-MERCON® Automatic
Transmission Fluid.
(5) Internal components binding, worn or damaged. (5) Disassemble unit and replace worn or damaged
components as necessary.
TRANSFER CASE NOISY (1} Insufficient or incorrect lubricant. (1) Drain and refill to edge of fill hole with
IN ALL DRIVE MODES DEXRON II® or MOPAR-MERCON® Automatic
Transmission Fluid. Check for leaks and repair if
necessary. Note: If unit is still noisy after
drain and refill, disassembly and
inspection may be required to locate
source of noise.
NOISY IN — OR JUMPS (1) Transfer case not completely engaged in 4L (1) Stop vehicle, shift transfer case to Neutral, then
OUT OF — FOUR WHEEL position. shift back into 4L position.
DRIVE LOW RANGE
(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 (4) Disassemble unit and repair as necessary.
binding on shift rail. ;
(5) Disassemble and repair as necessary.
(5) Low range gear worn or damaged.
LUBRICANT LEAKING (1) Transfer case overfilled. (1) Drain to correct level.
FROM OUTPUT SHAFT
SEALS OR FROM VENT (2) Vent closed or restricted. (2) Clear or replace vent if necessary.
(3) Output shaft seals damaged or installed (3) Replace seals. Be sure seal lip faces interior of
incorrectly. case when installed. Also be sure yoke seal
surfaces are not scored or nicked. Remove scores
and nicks with fine sandpaper or replace yoke(s)
if necessary.
ABNORMAL TIRE WEAR (1) Extended operation on dry hard surface (paved) {1) Operate in 2H on hard surface (paved) roads.
roads in 4H range.
J9021-118
REMOVAL AND INSTALLATION
SHIFT LEVER
REMOVAL
(1) Shift transfer case into 4L. (2) Raise vehicle. (3) Loosen adjusting trunnion locknut and slide shift rod out of trunnion (Fig. 2). If rod lacks enough travel to come out of trunnion, push trunnion out of torque shaft.
(4) Lower vehicle. (5) Remove console. Refer to park brake section in Group 5 for procedures.
(6) Remove screws attaching lever assembly to floorpan and remove assembly and shift rod (if left attached).
INSTALLATION
(1) If shift rod was not removed from lever assembly, work rod down through floorpan opening. Then position lever assembly on floorpan and install assembly attaching screws.
(2) Install console. (3) Raise vehicle. (4) Connect trunnion to torque shaft arm. Or, slide shift rod into trunnion on range lever. Be sure shift rod slides freely in trunnion.
(5) Verify that range lever is in 4L position. Then tighten trunnion lock bolt.
(6) Lower vehicle and check transfer case shift operation.
NV231 TRANSFER CASE
REMOVAL
(1) Shift transfer case into Neutral. (2) Raise vehicle. (3) Drain transfer case lubricant. (4) Mark front and rear propeller shaft yokes for alignment reference.
(5) Support transmission with jack stand. (6) Remove rear crossmember, or skid plate. (7) Disconnect front/rear propeller shafts at transfer case.
(8) Disconnect vehicle speed sensor wires. (9) Disconnect transfer case linkage rod from range lever.
(10) Disconnect transfer case vent hose, and indicator or vacuum switch harness.
(11) Support transfer case with transmission jack. (12) Remove nuts attaching transfer case to transmission.
(13) Secure transfer case to jack with chains. (14) Pull transfer case and jack rearward to disengage transfer case.
(15) Remove transfer case from under vehicle. (16) If transfer case was removed for overhaul, remove damper from rear retainer.
TRANSFER CASE INSTALLATION
(1) Mount transfer case on a transmission jack. Secure transfer case to jack with chains.
(2) Position transfer case under vehicle. (3) Align transfer case and transmission shafts and install transfer case on transmission.
(4) Install and tighten transfer case attaching nuts to 35 N·m (26 ft. lbs.) torque.
(5) Install damper on rear retainer (Fig. 3). Tighten damper attaching nuts to 54 N·m (40 ft. lbs.) torque.
(6) Connect vehicle speed sensor wires, and vent hose.
(7) Connect indicator or vacuum switch harness to transfer case switch. Secure wire harnesses to clips on transfer case.
(8) Align and connect propeller shafts. Tighten shaft attaching bolts to 19 N·m (170 in. lbs.) torque.
(9) Fill transfer case with Mopar Dexron II fluid. (10) Install rear crossmember, or skid plate. Tighten crossmember bolts to 41 N·m (30 ft. lbs.) torque.
(11) Remove transmission jack and support stand. (12) Connect shift rod to transfer case range lever. (13) Adjust transfer case shift linkage.
(14) Lower vehicle and verify transfer case shift operation.
DISASSEMBLY AND ASSEMBLY
NV231 TRANSFER CASE
DISASSEMBLE
SPEEDOMETER/YOKE/RANGE LEVER REMOVAL
(1) Remove speedometer adapter and pinion if not previously removed previously.
(2) Remove front yoke nut: Move range lever to 4L position. Then remove nut with 1–1/8 socket and impact wrench (Fig. 4).
(3) Remove yoke. If yoke is difficult to remove by hand, remove it with bearing splitter, or with standard two jaw puller (Fig. 5). Be sure puller tool is positioned on yoke and not on slinger as slinger will be damaged.
(4) Remove seal washer from front output shaft. Discard washer as it should not be reused.
(5) Remove nut and washer that attach range lever to sector shaft. Then move sector to neutral position and remove range lever from shaft. (Fig. 6)
REAR RETAINER REMOVAL AND DISASSEMBLY
(1) Remove mainshaft boot. Spread band clamp that secures boot on slinger with pliers and screwdriver. Then slide boot off shaft (Fig. 7).
(2) Remove rear slinger with brass drift and hammer (Fig. 8). Rotate slinger and tap at four positions 90 degrees apart to remove it. Discard slinger as it is not reusable.
CAUTION: Exercise care when removing the slinger. The rear retainer can be damaged by the drift punch.
(3) Remove rear seal from retainer (Fig. 9). Use pry tool, or collapse seal with punch to remove it.
(4) Remove slinger locating washer and locating retaining ring from output shaft (Fig. 10)
(5) Remove rear output bearing I.D. retaining ring (Fig. 11).
(6) Remove rear retainer bolts with 10mm socket and air ratchet.
(7) Remove rear retainer. Tap retainer with mallet and pry upward to break sealer bead. Then slide retainer off case and mainshaft (Fig. 12).
Removal
(8) Remove rear bearing O.D. retaining ring with snap ring pliers. Then tilt pump and slide it off mainshaft (Fig. 14)
(9) Remove pickup tube O-ring from pump (Fig. 15) but do not disassemble pump; it is not a repairable part.
(10) Remove seal from oil pump with pry tool.
(11) Remove bolts attaching rear case to front case. A 10 mm, 12 point socket is needed for the spline head bolt (Fig. 13). A 15 mm socket is needed for the remaining bolts. Note position of the two black finish bolts at each end of the case. These bolts go through the case dowels and require a washer under the bolt head (Fig. 16)
(12) Remove rear case from front case (Fig. 17). Insert screwdrivers into slots cast into each end of case. Then pry upward to break sealer bead and remove rear case.
CAUTION: Do not pry on the sealing surface of either case half as the surfaces will become damaged.
(13) Remove oil pickup tube and screen from rear case (Fig. 18).
FRONT SHAFT/DRIVE CHAIN/POPPET REMOVAL
(1) Remove poppet plug, spring and plunger (Fig. 19).
(2) Pull front output shaft upward and out of front bearing (Fig. 20).
(3) Slide drive chain off mainshaft sprocket and remove front output shaft and chain as assembly (Fig. 21).
MAINSHAFT REMOVAL AND DISASSEMBLY
(1) Grasp end of mainshaft and remove shaft, drive sprocket and mode hub as assembly (Fig. 22).
(2) Remove mode hub retaining ring with heavy duty snap ring pliers (Fig. 23).
(3) Slide mode hub off mainshaft (Fig. 24). (4) Slide drive sprocket off mainshaft (Fig. 25).
Bearing
Removal
SHIFT FORK/SLEEVE/HUB REMOVAL
(1) Remove mode spring from end of mode fork rail.
(2) Remove mode fork and sleeve as assembly (Fig. 26). Note position of sleeve for assembly installation (short side of sleeve faces up).
(3) Remove range fork and hub as assembly. Note fork position for installation reference (Fig. 27).
(4) Remove shift sector from front case (Fig. 28).
(5) Remove sector shaft O-ring seal and nylon retainer (Fig. 29)
INPUT GEAR/PLANETARY CARRIER REMOVAL AND DISASSEMBLY
(1) Remove input retainer attaching bolts with 10mm socket and air ratchet. (2) Remove input retainer. Pry retainer loose with screwdriver positioned in slots at each end of retainer (Fig. 30)
(3) Remove input retainer seal. Position retainer upside down over front case bearing. Then tap seal out with drift and hammer.
(4) Remove input gear bearing retaining ring with heavy duty snap ring pliers (Fig. 31)
(5) Place front case in horizontal position. Then remove input gear and planetary carrier as assembly (Fig. 32). Tap gear out of bearing with plastic mallet if necessary.
(6) Remove carrier lock retaining ring (Fig. 33).
(7) Remove input gear, lock ring, and front thrust washer from planetary carrier (Fig. 34).
thrust Washer Removal
(8) Remove rear thrust washer from carrier (Fig. 35).
(9) Remove pilot bearing from input gear with Tool MD-998346 as follows:
(a) Turn puller tool bolt until jaws retract enough to fit into bearing (Fig. 36)
(b) . (c) Insert puller bolt and jaws into bearing. Then turn puller bolt clockwise so ramp on bolt spreads jaws forcing them under bearing (Fig. 37).
(d) Install puller bridge over puller bolt (Fig. 38). Then install flat washer and nut on bolt. (e) Hold puller bridge from turning with locking pliers. Then tighten nut on puller bolt in clockwise direction to draw bearing out of input gear (Fig. 39).
Bearing
FRONT/REAR CASE BEARING AND SEAL REMOVAL
(1) Remove front output shaft front bearing and seal as follows:
(a) Remove seal from case with pry tool (Fig. 40). (b) Remove bearing retaining ring with screwdriver (Fig. 41).
(c) Remove bearing with Tool Handle C-4171 and Tool 5065 (Fig. 42). (2) Remove front output shaft rear bearing from rear case with Tool MD-998346 (Fig. 43). Be sure tool jaws are seated under bearing before tightening puller nut.
(3) Remove input bearing from front case. Tap bearing out from inside of case with brass drift and hammer.
NV231 TRANSFER CASE ASSEMBLE
CAUTION: The bearing bores in various transfer case components contain oil feed holes. Make sure replacement bearings do not block the holes.
INPUT GEAR, PLANETARY CARRIER, AND INPUT RETAINER INSTALLATION
(1) Lubricate bearings, input gear, and planetary carrier with transmission fluid during installation.
Removal
Seals can be lubricated with transmission fluid, petrolatum, or Ru-Glyde if desired.
(2) Install new input bearing in front case. Start bearing in bore with copper mallet. Tap bearing at 6–8 points around outer race to start it evenly. Mount case in shop press and seat bearing in case using hard wood block as press tool. Press bearing inward until bearing locating ring stops against case surface (Fig. 44).
(3) Install front output shaft front bearing in case with Tool Handle C-4171 and Installer 5064 (Fig. 45).
(4) Install shaft front bearing retaining ring (Fig. 46). Start ring into place by hand. Then use small screwdriver to work ring into case groove. Be sure ring is fully seated before proceeding.
(5) Install new front output seal in case bore with Tools C-4171 and 7934 (Fig. 47).
(6) Install pilot bearing in input gear with Tools C-4171 and 5065 (Fig. 48).
(7) Assemble input gear and planetary carrier as follows:
(a) Install rear thrust washer in carrier. Be sure washer tabs are aligned and seated in carrier slots
(Fig. 49). Also note that washers are the same and therefore interchangeable.
(b) Position front thrust washer and lock ring on input gear. Then install assembled parts in carrier (Fig. 50)
(c) Install carrier lock retaining ring. Use small screwdriver to work ring into place. Be sure ring is fully seated before proceeding (Fig. 51).
Lock Ring Installation
(8) Install assembled input gear/planetary carrier in front case (Fig. 52). Be sure to align carrier pin-
ions in annulus gear. Use wood hammer handle or rawhide mallet to seat assembly if necessary.
(9) Install input gear retaining ring (Fig. 53). Be sure to install the correct retaining ring as the input gear and mode hub retaining rings are almost the same diameter. The difference is in ring thickness with the input gear retaining ring being substantially thicker.
(10) Install new seal in input retainer with Tools C-4171 and 7884 (Fig. 54).
(11) Apply 3 mm bead of Mopar Sealer P/N 82300234, or Loctite Ultra Gray to front bearing retainer seal surface (Fig. 55).
Retainer
(12) Align oil channel in retainer with oil feed hole in front case (Fig. 56).
(13) Align and install input retainer on front case (Fig. 57).
(14) Install and tighten input retainer bolts to 16–24 N.m (12–18 ft. lbs.) torque.
SHIFT SECTOR/POPPET/RANGE FORK/RANGE HUB INSTALLATION
(1) Install shift sector O-ring and nylon retainer in case bore. Note that one side of retainer is slightly rounded and that the opposite side has a shallow
Hole In Front Case
groove. Groove side goes toward seal and rounded side faces out.
(2) Install shift sector in case (Fig. 58). Lubricate sector shaft with transmission fluid before installation.
(3) Install range lever, washer, and nut on sector shaft (Fig. 59). Tighten range lever nut to 27–34 N.m (20–25 ft. lbs.) torque.
(4) Assemble and install range fork and hub (Fig. 60). Be sure hub is properly seated in planetary carrier and engaged with input gear.
(5) Align and insert range fork pin in shift sector slot.
(6) Install poppet plunger, spring, and screw plug (Fig. 19). Install new O-ring on screw plug if necessary. Tighten plug to 16–24 N.m (12–18 ft. lbs.) torque.
MAINSHAFT AND MODE FORK INSTALLATION
(1) Lubricate mainshaft and hub and sprocket bores with transmission fluid.
(2) Install drive sprocket on mainshaft. (3) Install mode hub on mainshaft. (4) Install mode hub retaining ring. Be sure ring is fully seated in shaft groove before proceeding.
(5) Install assembled mainshaft, sprocket and hub (Fig. 61). Be sure shaft is seated in pilot bearing, planetary, and range sleeve.
(6) Install new pads on mode fork if necessary.
(7) Insert mode sleeve in mode fork mode fork. Be sure long side of sleeve is toward long end of shift rail (Fig. 62).
(8) Install assembled mode fork and sleeve (Fig. 63). Be sure fork rail goes through range fork and into case bore. Also be sure sleeve is aligned and seated on mainshaft hub.
DRIVE CHAIN AND FRONT OUTPUT SHAFT INSTALLATION
(1) Lubricate chain and front shaft with automatic transmission fluid.
(2) Install drive chain on front output shaft. (3) Lift chain and shaft upward and start chain around mainshaft drive sprocket.
(4) Install front output shaft. Tilt shaft and insert it into front bearing. Then work shaft and drive chain into place (Fig. 64).
(5) Install mode spring on upper end of mode fork shift rail (Fig. 64).
Installation
OIL PUMP AND REAR CASE ASSEMBLY/INSTALLATION
(1) Assemble oil pickup screen, connecting hose, and tube.
(2) Install new pickup tube O-ring in oil pump (Fig. 65).
(3) Install new seal in oil pump with Installer Tool 7588 (Fig. 66). (4) Insert oil pickup tube in oil pump inlet.
(5) Position assembled oil pump and pickup tube in rear case. Be sure pickup screen is securely seated in case slot. Also be sure oil pump locating tabs are outside rear case (Fig. 67).
(6) Apply bead of sealer to mating surface of front case. Use Mopar Sealer P/N 82300234, or Loctite Ultra Gray. Sealer bead should not exceed 3/16 in. in diameter.
(7) Lift rear case and oil pump and carefully position assembly on front case. Be sure case dowels are aligned and that mode fork rail extends through rear case before seating rear case on front case.
(8) Install bolts that attach rear case to front case. Be sure to use a washer with each of the two dowel bolts (Fig. 16). Tighten all bolts (including spline head bolt), to 27– 34 N.m (20–25 ft. lbs.) torque.
REAR RETAINER ASSEMBLY AND INSTALLATION
(1) Install rear bearing in retainer with Tools C-4171 and 5064 (Fig. 68).
(2) Install rear bearing O.D. retaining ring with snap ring pliers (Fig. 69). Be sure retaining ring is fully seated in retainer groove.
(3) Apply bead of Mopar Sealer P/N 82300234, or Loctite Ultra Gray to mating surface of rear retainer. Sealer bead should be a maximum of 3/16 in.
(4) Install rear retainer on rear case. Tighten retainer bolts to 20–27 N.m (15–20 ft. lbs.) torque.
(5) Install rear bearing I.D. retaining ring and spacer on mainshaft.
(6) Apply liberal quantity of petroleum jelly to new rear seal and to mainshaft. Petroleum jelly is needed to protect seal lips during installation.
(7) Slide new rear seal onto mainshaft and into place in rear retainer. Start seal in retainer by hand then carefully seat seal with hammer and Tool D-389 (Fig. 70).
(8) Install new rear slinger. Use suitable size pipe tool to tap slinger into place.
(9) Install boot on mainshaft and slinger. Secure boot to slinger with new band clamp.
FRONT YOKE AND SWITCH INSTALLATION
(1) Install vacuum or indicator switch in front case. Tighten switch to 20–34 N.m (15–25 ft. lbs.) torque.
(2) Lubricate yoke hub with transmission fluid and install yoke on front shaft.
(3) Install new seal washer on front shaft. (4) Install yoke on front shaft. Secure yoke with new nut.
CLEANING AND INSPECTION
NV231 TRANSFER CASE
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.
The oil pickup screen can be cleaned with solvent. Shake excess solvent from the screen after cleaning and allow it to air dry. Do not use compressed air.
MAINSHAFT/SPROCKET/HUB INSPECTION
Inspect the splines on the hub and shaft and the teeth on the sprocket (Fig. 71). Minor nicks and scratches can be smoothed with an oilstone, however, replace any part 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 (Fig. 72). 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. 73). Minor nicks on the shift rail can be smoothed with 320–400 grit emery cloth.
Inspect the shift fork wear pads (Fig. 74). 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/BEARING/ SEAL/SLINGER/ BOOT
Inspect the retainer components (Fig. 75). Replace the bearing if rough or noisy. Check the retainer for cracks or wear in the bearing bore. Clean the
retainer sealing surfaces with a scraper and 3M all purpose cleaner. This will ensure proper adhesion of the sealer during reassembly.
Replace the slinger and seal outright; do not reuse either part.
Inspect the retaining rings and washers. Replace any part if distorted, bent, or broken. Reuse is not recommended. Also replace the boot if cut or torn. Replace the boot band clamps, do not reuse them.
REAR OUTPUT SHAFT/YOKE/DRIVE CHAIN
Check condition of the seal contact surfaces of the yoke slinger (Fig. 76). This surface must be clean and smooth to ensure proper seal life. Replace the yoke nut and seal washer as neither part should be reused.
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 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 (Fig. 77)
FRONT-REAR CASES AND FRONT RETAINER
Inspect the cases and retainer for wear and damage. Clean the sealing surfaces with a scraper and 3M all purpose cleaner. This will ensure proper sealer adhesion at assembly. Replace the input retainer seal; do not reuse it.
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.
ADJUSTMENTS
SHIFT LINKAGE ADJUSTMENT
(1) Shift transfer case into 4L position. (2) Raise vehicle. (3) Loosen lock bolt on adjusting trunnion (Fig. 78). (4) Be sure linkage rod slides freely in trunnion. Clean rod and apply spray lube if necessary.
(5) Verify that transfer case range lever is fully engaged in 4L position.
(6) Tighten adjusting trunnion lock bolt. (7) Lower vehicle.
SPECIFICATIONS
TORQUE
DESCRIPTION TORQUE Plug, Detent . . . . . . . . . . .16–24 N·m (12–18 ft. lbs.) Bolt, Diff. Case . . . . . . . . .17–27 N·m (15–24 ft. lbs.) Plug, Drain/Fill . . . . . . . . .40–45 N·m (30–40 ft. lbs.) Bolt, Extension Housing . .35–46 N·m (26–34 ft. lbs.) Bolt, Front Brg. Retainer. .16–27 N·m (12–20 ft. lbs.) Bolt, Case Half . . . . . . . . .35–46 N·m (26–34 ft. lbs.) Nut, Front Yoke . . . . . .122–176 N·m (90–130 ft. lbs.) Screw, Oil Pump . . . . . . .1.2–1.8 N·m (12–15 in. lbs.) Nut, Range Lever . . . . . . .27–34 N·m (20–25 ft. lbs.) Bolt, Rear Retainer . . . . . .35–46 N·m (26–34 ft. lbs.) Nuts, Mounting . . . . . . . . .35–47 N·m (26–35 ft. lbs.) Bolts, U-Joint . . . . . . . . . . . . . . . .19 N·m (17 ft. lbs.) Vacuum Switch . . . . . . . . .20–34 N·m (15–25 ft. lbs.)
SPECIAL TOOLS
SPECIAL TOOLS—NV231
C-4171 Handle Universal (Non Threaded)
C-4210 Installer, Seal
5061 Installer, Bearing
5062 Installer, Bearing
5063 Installer, Bearing
5064 Installer, Bearing
5065 Installer, Bearing
5066 Installer, Bushing
7828-A Installer, Input Gear Bearing
7888 Installer, Pump Housing Seal
7889-A Remover, Rear Output Shaft Bushing
NV249 TRANSFER CASE
INDEX
GENERAL INFORMATION
GENERAL INFORMATION . . . . . . . . . . . . . . . . 170 RECOMMENDED LUBRICANT AND
FILL LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . 170 DIAGNOSIS AND TESTING
NV249 DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . 171 SERVICE PROCEDURES
RECOMMENDED LUBRICANT AND
FILL LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . 172 REMOVAL AND INSTALLATION
SPEEDOMETER . . . . . . . . . . . . . . . . . . . . . . . . 172 TRANSFER CASE BEARINGS AND SEALS . . . 174
GENERAL INFORMATION
GENERAL INFORMATION
The NV249 is an all the time, transfer case with two operating ranges and a neutral position.
Operating ranges are 4-high and 4-low. The 4-low range is used for extra pulling power in off road situations.
Engine torque is distributed to the front and rear axles through a viscous coupling. The NV249 low range is provided by a gear reduction system for increased low speed, off road torque capability.
Shift Mechanism Transfer case operating ranges are selected with a floor mounted shift lever. The shift lever is connected to the transfer case range lever by an adjustable linkage rod. Range positions are marked on the shifter bezel plate.
SHIFT MECHANISM
Transfer case operating ranges are selected with a floor mounted shift lever. The shift lever is connected to the transfer case range lever by an adjustable linkage rod. Range positions are marked on the shifter bezel plate.
TRANSFER CASE IDENTIFICATION
A circular I.D. tag is attached to the rear case of each NV249 transfer case (Fig. 1). 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.
page page
TRANSFER CASE . . . . . . . . . . . . . . . . . . . . . . 173 DISASSEMBLY AND ASSEMBLY
INPUT AND LOW RANGE GEAR . . . . . . . . . . . 187 TRANSFER CASE . . . . . . . . . . . . . . . . . . . . . . 178 CLEANING AND INSPECTION
NV249 COMPONENTS . . . . . . . . . . . . . . . . . . . 188 ADJUSTMENTS
SHIFT LINKAGE ADJUSTMENT . . . . . . . . . . . . 189 SPECIFICATIONS
TORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 SPECIAL TOOLS
NV249 TRANSFER CASE . . . . . . . . . . . . . . . . . 191
RECOMMENDED LUBRICANT AND FILL LEVEL
Mopar Dexron II, or ATF Plus are the only lubricants recommended for the NV249 transfer case. Approximate fluid refill capacity is approximately 1.18 liters (2.50 pints). Correct fill level is to the bottom edge of the fill plug hole.
DIAGNOSIS AND TESTING
NV249 DIAGNOSIS
DIFFICULT TO SHIFT shifting. range. Or reduce speed to 3-4 km/h
OR WILL NOT SHIFT (2-3 mph) before attempting to shift.
INTO DESIRED (b) Stop vehicle, shift transmission to
RANGE {b) If vehicle was operated for extended neutral, shift transfer case to 2H mode
period in 4H mode on dry paved and operate vehicle on 2H on dry
surface, driveline torque load may paved surface.
cause difficulty. — (c) Lubricate, repair or replace linkage, or
(c) Transfer case external shift linkage tighten loosen components as necessary.
binding. (d) Drain and refill to edge of fill hole with
d) Insuffici . lubri MOPAR ATF PLUS (Type 7176) or
(d) Insufficient or incorrect lubricant. DEXRON II Automatic Transmission
Fluid.
(e) Disassemble unit and replace worn or
(e) Internal components binding, worn or damaged components as necessary.
damaged.
TRANSFER CASE (a) Insufficient or incorrect lubricant. (a) Drain and refill to edge of fill hole with
NOISY IN ALL MOPAR ATF PLUS (Type 7176) or
DRIVE MODES DEXRON II Automatic Transmission
Fluid. Check for leaks and repair if
necessary, If unit is still noisy after
rain and refill, disassembly an
inspection may be required to locate
source of noise.
(a) Stop vehicle, shift transfer case to
NOISY IN—OR {a) Transfer case not completely engaged Neutral, then shift back into 4L position.
POR ORIVE in 4L position. (b) Tighten, lubricate, or repair linkage as
- - ao. 4 necessary.
LOW RANGE (b) Shift linkage loose or binding. (c) Disassemble unit and repair as
c) Range fork cracked, inserts worn, or necessary . .
binding on shift rail. “ (d) Disassemble unit and repair as
(d) Annulus gear or lockplate work or necessary
damaged. (a) Drain to correct level.
LUBRICANT (a) Transfer case overfilled. (b) Clear or replace vent if necessary.
OUP. SAE (b) Vent closed or restricted. (c) Replace seals. Be sure seal lip faces
SEALS OR FROM (c) Output shaft seals damaged or interior of case when installed. Also be
VENT installed correc si Remove scores and nicks with
icked.
fine sandpaper or replace yoke(s) if
necessary.
(a) Operate in 2H on hard surface (paved)
ABNORMAL (a) Extended operation on dry hard roads.
TIRE WEAR surface (paved) roads in 4H range.
J9021-152
SERVICE PROCEDURES
RECOMMENDED LUBRICANT AND FILL LEVEL
Mopar Dexron II, or ATF Plus are the only lubricants recommended for the NV249 transfer case. Approximate fluid refill capacity is approximately 1.18 liters (2.50 pints). Correct fill level is to the bottom edge of the fill plug hole.
REMOVAL AND INSTALLATION
SPEEDOMETER
REMOVAL
(1) Raise vehicle. (2) Disconnect wires from vehicle speed sensor. (3) Remove adapter clamp and screw (Fig. 2). (4) Remove speed sensor and speedometer adapter as assembly.
(5) Remove speed sensor retaining screw and remove sensor from adapter.
(6) Remove speedometer pinion from adapter. Replace pinion if chipped, cracked, worn.
(7) Inspect sensor and adapter O-rings (Fig. 2). Remove and discard O-rings if worn or damaged.
(8) Inspect terminal pins in speed sensor. Clean pins with Mopar electrical spray cleaner if dirty or oxidized. Replace sensor if faulty, or pins are loose, severely corroded, or damaged.
SPEEDOMETER INSTALLATION AND INDEXING
(1) Thoroughly clean adapter flange and adapter mounting surface in housing. Surfaces must be clean for proper adapter alignment and speedometer operation.
(2) Install new O-rings on speed sensor and speedometer adapter if necessary (Fig. 2).
(3) Lubricate sensor and adapter O-rings with transmission fluid.
(4) Install vehicle speed sensor in speedometer adapter. Tighten sensor attaching screw to 2-3 N·m (15-27 in. lbs.) torque.
(5) Install speedometer pinion in adapter. (6) Count number of teeth on speedometer pinion. Do this before installing assembly in housing. Then lubricate pinion teeth with transmission fluid.
(7) Note index numbers on adapter body (Fig. 3). These numbers will correspond to number of teeth on pinion.
(8) Install speedometer assembly in housing. (9) Rotate adapter until required range numbers are at 6 o-clock position. Be sure range index numbers correspond to number of teeth on pinion gear.
(10) Install speedometer adapter clamp and retaining screw. Tighten clamp screw to 10-12 N·m (90-110 in. lbs.) torque.
(11) Connect wires to vehicle speed sensor. (12) Lower vehicle and top off transmission fluid level if necessary.
Adapter
TRANSFER CASE
REMOVAL
(1) Shift transfer case into Neutral. (2) Raise vehicle. (3) Drain transfer case lubricant. (4) Mark front and rear propeller shaft yokes for alignment reference.
(5) Place support stand under transmission. (6) Remove rear crossmember. (7) Then disconnect shafts at transfer case. (8) Disconnect speed sensor and remove speedometer adapter and sensor if necessary.
(9) Disconnect transfer case shift lever from shift lever rod.
(10) Disconnect vent hose and indicator switch. Remove hoses and wires from retainers on transfer case.
(11) Support transfer case with transmission jack. (12) Remove nuts attaching transfer case to transmission adapter.
(13) Secure transfer case to jack with safety chains.
(14) Pull transfer case and jack rearward to disengage transfer case.
(15) Remove transfer case from under vehicle.
TRANSFER CASE INSTALLATION
(1) Mount transfer case on a transmission jack. Secure transfer case to jack with safety chains.
(2) Position transfer case under vehicle. (3) Align transfer case and transmission shafts and install transfer case on transmission (Fig. 4).
(4) Install and tighten transfer case attaching nuts (Fig. 4). Tighten 3/8 nuts to 41-47 N·m (30-35 ft. lbs.). Tighten 5/16 nuts to 30-35 N·m (22-26 ft. lbs.).
(5) Install speedometer adapter if removed during service. Then index adapter and install speed sensor
in adapter. Refer to Speedometer removal and installation for indexing procedure.
(6) Connect electrical wires to speed sensor and indicator switch.
(7) Connect vent hose to transfer case vent (Fig. 5).
(8) Align and connect propeller shafts. Tighten shaft attaching bolts to 19 N·m (170 in. lbs.) torque.
(9) Fill transfer case with Dexron II. Correct level is to bottom edge of fill plug hole.
(10) Install rear crossmember if removed. Tighten crossmember bolts to 41 N·m (30 ft. lbs.) torque.
(11) Remove transmission jack and transmission support stand.
(12) Connect transfer case shift lever to shift lever rod. (13) Check and adjust transfer case shift linkage if necessary.
(14) Lower vehicle.
TRANSFER CASE BEARINGS AND SEALS
OUTPUT SHAFT FRONT SEAL
(1) Hoist vehicle and support on safety stands. (2) Remove front propeller shaft, refer to Group 3, Differential and Driveline for proper procedure.
(3) Remove front output shaft yoke. (4) Remove seal from front case with pry tool (Fig. 6).
(5) Install new front output seal in front case with Installer Tool 6952 and Tool Handle C-4171 as follows:
(a) Place new seal on tool. Garter spring on seal goes toward interior of case.
(b) Start seal in bore with light taps from hammer (Fig. 7). Once seal is started, continue tapping seal into bore until installer tool bottoms against case.
OUTPUT SHAFT FRONT BEARING
The transfer case housing must be disassembled to replace to output shaft front bearing (Fig. 8).
(1) Remove snap ring that retains front bearing in front case (Fig. 9).
Removal
(2) Using tool 6953, remove bearing from front case (Fig. 10).
(3) Using tool 6953, install new bearing. (4) Install snap-ring to hold bearing into case. (5) Assemble transfer case.
REPLACING FRONT OUTPUT SHAFT REAR BEARING
The transfer case must be disassembled to replace the front output shaft rear bearing.
Using Puller 7794A and Slide Hammer C-637 with Adapter 7420-8, pull the output shaft rear bearing from the rear case (Fig. 12).
Using Tool Handle C-4171 and Installer 5066, install the new bearing with (Fig. 13). The bearing
bore is chamfered at the top. Install the bearing so it is flush with the lower edge of this chamfer (Fig. 14).
REPLACING FRONT BEARING
The transfer case must be disassembled to replace the front bearing. The same tool is used to remove and install the front bearing. Replace the bearing only as described to avoid damaging the front case.
(1) Remove input gear from front bearing.
(2) Remove input gear front seal retainer. (3) Using Remover/Installer 7823 and Handle C-4171, drive front bearing from inside the annulus opening in the case. (Fig. 15).
(4) If necessary, install locating ring on new bearing (Fig. 16).
(5) Position case so forward end is facing upward. (6) Using Remover/Installer 7823 and Handle C-4171, drive front bearing into case (Fig. 16). The bearing locating ring must be fully seated against case surface.
REPLACING FRONT BEARING RETAINER SEAL
If the front seal is the cause of a fluid leak, replace the seal and seal the retainer with Mopar, RTV Gasket Maker.
(1) Remove front seal retainer. (2) Using a suitable driver, remove seal from retainer.
(3) Clean gasket sealer residue from retainer and inspect retainer for cracks or other damage.
(4) Using Installer 6952, install seal into the retainer.
CAUTION: Do not block fluid return cavity on sealing surface of retainer when applying RTV sealer. Seal failure and fluid leak can result.
(5) Apply a 3 mm (1/8 in.) bead of RTV sealer to sealing surface of retainer.
(6) Align cavity in seal retainer with fluid return hole in front of case.
(7) Install bolts to hold retainer to transfer case.
REPLACING INPUT GEAR PILOT BEARING
The input gear must be removed to replace the mainshaft pilot bearing.
(1) Using a suitable drift inserted into the splined end of the input gear, drive pilot bearing from input gear (Fig. 17).
(2) Wash input gear in solvent to remove fluid residue.
(3) Apply a thin coat of Mopar, Lock N’Seal sealer to outside surface of pilot bearing.
(4) Using Installer 6954 and Handle C-4171, drive pilot bearing into input gear until installer bottoms out (Fig. 18).
(5) Install input gear in transfer case.
REPLACING EXTENSION HOUSING SEAL
It is not necessary to remove the transfer case to replace the extension housing seal.
(1) Hoist and support vehicle on safety stands.
(2) Remove propeller rear propeller shaft, refer to Group 3, Differential and Driveline for proper procedure.
(3) Using Remover C-3985B, remove seal from housing (Fig. 19).
(4) Clean fluid residue from sealing surface and inspect for defects. Replace housing if cracked.
(5) Using Installer C-3995A or C–3972A, install seal in extension housing (Fig. 20).
(6) Install propeller shaft. (7) Verify proper fluid level. (8) Lower vehicle.
REPLACING REAR RETAINER SEAL AND BUSHING
(1) Remove extension housing seal. (2) Using Remover 6957, remove bushing from extension housing (Fig. 21).
(3) Clean fluid residue from extension housing and inspect for cracks. Replace housing if damaged.
(4) Position replacement bushing in extension housing with fluid port in bushing aligned with slot in housing.
(5) Using Installer C-4735, drive bushing into housing until installer bottoms out (Fig. 22).
(6) Install extension housing seal.
DISASSEMBLY AND ASSEMBLY
TRANSFER CASE
TRANSFER CASE DISASSEMBLY
(1) Position transfer case on shallow drain pan. Remove drain plug and drain lubricant remaining in case.
(2) Remove front yoke nut and remove yoke (Fig. 23). (3) Remove yoke seal washer from front output shaft (Fig. 24).
(4) Remove rear retainer bolts (Fig. 25).
(5) Remove rear bearing locating ring access cover screws, cover and gasket (Fig. 26).
Removal
(6) Loosen rear retainer with pry tool to break sealer bead. Pry only against retainer boss as shown (Fig. 27).
(7) Remove rear retainer as follows: • Spread rear bearing locating ring with snap ring pliers (Fig. 28).
• Then slide retainer off mainshaft and rear bearing (Fig. 29).
(8) Remove speedometer drive gear (Fig. 30). (9) Remove rear bearing snap ring (Fig. 31).
(10) Remove rear bearing (Fig. 31). Note position of bearing locating ring groove for assembly reference.
(11) Disengage oil pickup tube from oil pump and remove oil pump assembly (Fig. 31).
(12) Mount transfer case on wood blocks so rear case is facing upward.
(13) Remove bolts holding front case to rear case. The case alignment bolt require flat washers (Fig. 32).
(14) Loosen rear case with flat blade screwdriver to break sealer bead. Insert screwdriver blade only into notches provided at each end of case (Fig. 33).
(15) Remove rear case (Fig. 34).
(16) Remove oil pickup tube from rear case (Fig. 35). (17) Remove oil pump locating snap ring and viscous coupling snap ring from mainshaft (Fig. 36).
(18) Remove viscous coupling from mainshaft (Fig. 36). (19) Remove drive gear snap ring (Fig. 37). (20) Disengage drive gear (Fig. 37). Pry gear upward and off mainshaft as shown.
(21) Remove front output shaft, drive chain and drive gear as assembly (Fig. 37).
Removal
(22) Remove detent plug, O-ring, detent spring and detent plunger (Fig. 38).