JEEP CHEROKEE 1995 Service Repair Manual

OPERATING RANGES
NP231 operating ranges are: 2-wheel drive high;
4-wheel drive high and 4-wheel drive low.
2-wheel drive range is for use on all road surfaces.
The 4-wheel drive high and low ranges are undiffer-
entiated and should only be used on unpaved, low
traction surfaces only. The only exception being when
hard surface roads are snow and ice covered.
SHIFT MECHANISM
Operating ranges are selected with a floor mounted
shift lever. The shift lever is connected to the trans-
fer 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 NP231 transfer case (Fig. 2). The ID tag pro-
vides 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
7-10-94 would represent July 10, 1994.TRANSFER CASE LUBRICANT AND FILL LEVEL
Recommended lubricant for the NP231 transfer
case is Mopar Dexron II.
Approximate lubricant refill capacity is 1.54 liters
(3.25 pints) for YJ and 1.04 liters (2.2 pints) for XJ.
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.
Fig. 2 Transfer Case Identification Tag
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NP231 SERVICE DIAGNOSIS
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SHIFT LINKAGE ADJUSTMENT
(1) Shift transfer case into 4L position.
(2) Raise vehicle.
(3) Loosen lock bolt on adjusting trunnion (Figs. 3
and 4).
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 en-
gaged in 4L position.
(6) Tighten adjusting trunnion lock bolt.
(7) Lower vehicle.
SHIFT LEVER REMOVAL (XJ)
(1) Shift transfer case into 4L.
(2) Raise vehicle.
(3) Loosen adjusting trunnion locknut and slide
shift rod out of trunnion (Fig. 4). 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).
SHIFT LEVER INSTALLATION (XJ)
(1) If shift rod was not removed from lever assem-
bly, work rod down through floorpan opening. Then
position lever assembly on floorpan and install as-
sembly 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 op-
eration.
SHIFT LEVER REMOVAL (YJ)
(1) Shift transfer case into neutral.
(2) Remove shift lever knob and retaining nut.
Then remove shift lever boot and bezel.
(3) Raise vehicle
(4) Loosen lock bolt in adjusting trunnion and slide
shift rod out of trunnion (Fig. 3).
(5) Remove bolts/nuts attaching bracket and brace
assembly to transmission (Fig. 5).
(6) Remove shift lever and bracket as assembly.
(7) YJ shift lever assembly is serviceable. If any
assembly part must be replaced, remove pivot bolt,
lever pin E-clip, and lever pin and spring. Then dis-
assemble and replace necessary part (Fig. 6).
SHIFT LEVER INSTALLATION (YJ)
(1) Assemble lever components, if necessary. Lube
pivot bolt and pin with Mopar multi-mileage grease
before installation.
(2) Work shift lever upward into vehicle interior.
Then position lever and bracket assembly on trans-
mission and install attaching bolts/nuts.
(3) Place transfer case range lever in 4L position.
Then slide shift rod into trunnion and tighten lock
bolt.
Fig. 3 Adjusting Trunnion And Lock Bolt (YJ)
Fig. 4 Shift Linkage (XJ)
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(4) Lower vehicle.
(5) Install shift lever bezel and boot (Fig. 7). Then
install retaining nut and shift knob on lever.
SPEEDOMETER SERVICE
Speedometer service is covered in the 30RH/32RH,
or AW-4 automatic transmission sections in this
group. Refer to the appropriate section as needed.
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 trans-
fer case.
(8) Disconnect vehicle speed sensor wires.
(9) Disconnect transfer case linkage rod from range
lever.
(10) Disconnect transfer case vent hose, and indi-
cator or vacuum switch harness.
(11) Support transfer case with transmission jack.
(12) Remove nuts attaching transfer case to trans-
mission.
(13) Secure transfer case to jack with chains.
Fig. 5 Shift Linkage Mounting (YJ)
Fig. 6 Shift Linkage (YJ)
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(14) Pull transfer case and jack rearward to disen-
gage transfer case.
(15) Remove transfer case from under vehicle.
(16) If transfer case was removed for overhaul, re-
move damper from rear retainer.
TRANSFER CASE INSTALLATION
(1) Mount transfer case on a transmission jack. Se-
cure 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 Nzm (26 ft. lbs.) torque.
(5) Install damper on rear retainer (Fig. 8).
Tighten damper attaching nuts to 54 Nzm (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 Nzm (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 Nzm (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.
Fig. 7 Transfer Case Shift Lever And Boots (YJ)
Fig. 8 Transfer Case Mounting
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TRANSFER CASE DISASSEMBLY AND OVERHAUL
Two versions of the NP231 are used in current
models. One version retains the synchronizer
components used in previous years. A newly intro-
duced version does not have synchro components.
The non-synchro version is not equipped with a
synchro gear, struts, springs, or stop ring. During
overhaul, note which version is being serviced
and order needed parts accordingly.
(1) Remove fill and drain plugs. Also remove speed-
ometer adapter and pinion if not previously removed.
(2) Remove front yoke. Discard yoke seal washer
and nut. They should not be reused.
(3) Move transfer case range lever rearward to 4L
position.
(4) Remove extension housing attaching bolts.
(5) Tap extension housing in clockwise direction to
break sealer bead and remove housing (Fig. 1).
CAUTION: To avoid damaging the sealing surfaces
of the extension housing and rear retainer, do not
pry or wedge the housing off the retainer.
(6) Remove rear bearing snap ring (Fig. 2).
(7) Remove rear retainer attaching bolts.
(8) Remove rear retainer. Position screwdriver un-
der each tab on retainer housing (Fig. 3). Then care-
fully pry retainer upward and off rear case.
CAUTION: Do not pry against the sealing surfaces
of the retainer or rear case. The surfaces could be
damaged.
(9) Remove bolts attaching rear case to front case.
Retain bolts and washers.
(10) Separate rear case from front case (Fig. 4) Insert
screwdrivers into slots cast in case ends. Then gently
pry upward to break sealer bead and loosen rear case.
CAUTION: Do not pry against the sealing surfaces of
the retainer or rear case. The surfaces could be dam-
aged.
Fig. 1 Extension Housing Removal
Fig. 2 Rear Bearing Snap Ring Removal
Fig. 3 Rear Retainer Removal
Fig. 4 Loosening Rear Case
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(11) Remove oil pump and rear case as an assem-
bly (Fig. 5).
(12) Slide oil pickup tube screen out of case pocket.
(13) Remove oil pump and pickup tube as assembly
(Fig. 6).(14) Disconnect screen from pickup tube and re-
move screen (Fig. 7).
(15) Remove pickup tube from oil pump (Fig. 7).
(16) Remove pickup tube O-ring from oil pump
(Fig. 8).
(17) Remove mode spring (Fig. 9).
Fig. 5 Rear Case And Oil Pump Removal
Fig. 6 Oil Pump And Pickup Tube Removal
Fig. 7 Removing Oil Screen And Pickup Tube
Fig. 8 Pickup Tube O-Ring Location
Fig. 9 Mode Spring Removal
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(18) Tap front output shaft upward with rawhide
mallet to free it from shaft bearing.
(19) Remove front output shaft and drive chain
(Fig. 10).
(20) Remove mainshaft, mode fork and shift rail as
assembly d (Fig. 11).
(21) Remove mode fork and shift rail from synchro
sleeve (Fig. 12).
(22) Remove hub snap ring and remove spacer if
equipped (Fig. 13).
(23) Remove sleeve from hub (Fig. 14).
Fig. 10 Front Output Shaft And Drive Chain
Removal
Fig. 11 Removing Mainshaft, Mode Fork And Shift
Rail
Fig. 12 Removing Mode Fork And Rail From Sleeve
Fig. 13 Hub Snap Ring And Spacer Removal
Fig. 14 Removing Sleeve From Hub
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(24) Remove hub from mainshaft. On synchro mod-
els, also remove synchro stop ring (Fig. 15).
(25) Remove drive sprocket (Fig. 16).
(26) Slide range fork pin out of shift sector (Fig.
17).
(27) Remove range fork and shift hub (Fig. 18).
(28) Remove range lever from sector shaft.
(29) Remove shift sector (Fig. 19).(30) Remove sector shaft bushing and O-ring (Fig.
20).
Fig. 15 Hub And Stop Ring Removal
Fig. 16 Drive Sprocket Removal/Installation
Fig. 17 Disengaging Range Fork
Fig. 18 Range Fork And Hub Removal/Installation
Fig. 19 Shift Sector Removal/Installation
Fig. 20 Removing/Installing Sector Shaft Bushing
And O-Ring
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(31) Remove shift detent plunger, spring and plug
(Fig. 21). Remove O-ring from plug after removal.
(32) Turn front case over and remove front bearing
retainer bolts (Fig. 22).
(33) Remove front bearing retainer. Position screw-
drivers in retainer slots and lift upward to loosen
and remove retainer (Fig. 23).
(34) Remove input gear snap ring (Fig. 24).
(35) Press input and low range gear assembly out
of input gear bearing with shop press (Fig. 25).
(36) Remove low range gear snap ring (Fig. 26).
(37) Remove retainer, thrust washers and input
gear from low range gear (Fig. 27).
(38) Remove oil seals from rear retainer, rear ex-
tension housing, oil pump feed housing and case
halves.
(39) Remove magnet from pocket in front case.
Fig. 21 Detent Component Removal
Fig. 22 Front Bearing Retainer Bolt Locations
Fig. 23 Removing Front Bearing Retainer
Fig. 24 Removing Input Gear Snap Ring
Fig. 25 Removing Input And Low Range Gear
Assembly
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