front JEEP CHEROKEE 1994 Service Repair Manual

(7) Remove clutch inner race from planetary gear
(Fig. 7).
(8) Remove clutch snap ring and remove No. 2 one-
way clutch from planetary (Fig. 8).
(9) Remove front and rear thrust washers from
planetary gear (Fig. 9).
(10) Remove thrust bearing and washers from ring
gear (Fig. 10).
(11) Remove ring gear snap ring and remove ring
gear hub (Fig. 11).
(12) Inspect and replace any worn or damaged
planetary gear components.
Fig. 7 Removing/Installing Clutch Inner Race
Fig. 5 Removing/Installing Rear Planetary
Fig. 3 Removing/Installing Shaft Seal Ring
Fig. 4 Removing/Installing First-Reverse Brake Pack
Fig. 6 Checking No. 2 One-Way Clutch Operation
JAW-4 TRANSMISSION OVERHAUL 21 - 235

(4) Install rear planetary gear, second brake drum
and output shaft as outlined in following steps:
(5) Verify No. 10 thrust bearing and race (Fig. 2).
Bearing and race outer diameter is 57.7 mm (2.272
in.) and inside diameter is 39.2 mm (1.543 in.).
(6) Coat thrust bearing and race assembly with pe-
troleum jelly and install in case (Fig. 3). Race faces
down. Bearing rollers face up.
(7) Align teeth of second brake drum and clutch
pack (Fig. 4).(8) Align rear planetary-output shaft assembly
teeth with case slots and install assembly in case
(Fig. 5).
(9) Install rear planetary snap ring with snap ring
pliers. Chamfered side of snap ring faces up and to-
ward case front (Fig. 6).
(10) Check first-reverse brake pack clearance with
feeler gauge. Clearance should be 0.70 - 1.20 mm
(0.028 - 0.047 in.). If clearance is incorrect, planetary
assembly, thrust bearing or snap ring is not properly
seated in case. Remove and reinstall components if
necessary.
(11) Install second brake piston sleeve (Fig. 8).
Sleeve lip faces up and toward case front as shown.
Fig. 3 Installing Thrust Bearing And Race (No. 10)
Fig. 4 Aligning Second Brake Drum And Clutch
Pack Teeth
Fig. 5 Installing Output Shaft And Rear Planetary
Assembly
Fig. 6 Installing Planetary Snap Ring
21 - 256 AW-4 TRANSMISSION OVERHAULJ

(17) Install No. 1 one-way clutch (Fig. 14). Short
flanged side of clutch faces up and toward case front.
(18) Install second brake pack (Fig. 15). Install
disc then plate. Continue installation sequence until
correct number of discs-plates are installed. Use five
discs and five plates.
(19) Install second brake pack retainer with
rounded edge of retainer facing disc.
(20) Install second brake pack snap ring.
(21) Check brake pack clearance with feeler gauge
(Fig. 16). Clearance should be 0.062 - 1.98 mm (0.024
- 0.078 in.). If brake pack clearance is not correct,
brake pack components are not seated. Reassemble
brake pack if necessary.
Fig. 14 Installing No. 1 One-Way Clutch
Fig. 12 Installing Park Rod Bracket
Fig. 13 Checking Park Pawl Engagement
Fig. 15 Installing Second Brake Pack
Fig. 16 Checking Second Brake Pack Clearance
21 - 258 AW-4 TRANSMISSION OVERHAULJ

(22) Install planetary sun gear and input drum
(Fig. 17). Be sure drum thrust washer tabs are
seated in drum. Use petroleum jelly to hold thrust
washer in position if necessary.
(23) Install front planetary gear on sun gear (Fig.
18).
(24) Support output shaft with wood blocks (Fig.
19).
(25) Install planetary snap ring on sun gear with
snap ring plier tool 7541 (Fig. 20).(26) Install tabbed thrust race on front planetary
gear (Fig. 21). Washer tabs face down and toward
gear. Race outer diameter is 47.8 mm (1.882 in.). In-
side diameter is 34.3 mm (1.350 in.).
(27) Install second coast brake band (Fig. 22).
(28) Install pin in second coast brake band. Then
install retaining ring on pin (Fig. 23).
(29) Install thrust bearing and race in forward-di-
rect clutch (Fig. 24). Coat bearing/race with petro-
leum jelly to hold them in place.
(30) Verify forward-direct clutch thrust bearing
size.
Fig. 17 Installing Sun Gear And Input Drum
Fig. 18 Installing Front Planetary Gear
Fig. 19 Supporting Output Shaft
Fig. 20 Installing Front Planetary Snap Ring
JAW-4 TRANSMISSION OVERHAUL 21 - 259

²Race outer diameter is 48.9 mm (1.925 in.) and in-
side diameter is 26.0 mm (1.024 in.).
²Bearing outer diameter is 46.7 mm (1.839 in.) and
inside diameter is 26.0 mm (1.024 in.).
(31) Coat front planetary ring gear race with pe-
troleum jelly and install it in ring gear (Fig. 25).
(32) Verify ring gear race size. Outer diameter is
47.0 mm (1.850 in.) and inside diameter is 26.5 mm
(1.045 in.).
(33) Align forward-direct clutch disc splines with
screwdriver (Fig. 26).
(34) Align and install front planetary ring gear in
forward-direct clutch (Fig. 27).
Fig. 24 Installing Forward-Direct Clutch Thrust Bearing
And Race
Fig. 21 Installing Planetary Thrust Race
Fig. 22 Installing Second Coast Brake Band
Fig. 23 Installing Second Coast Brake Band Retaining Pin
21 - 260 AW-4 TRANSMISSION OVERHAULJ

(35) Coat bearing and race with petroleum jelly
and install them in ring gear (Fig. 28). Verify bear-
ing/race size.
²Bearing outer diameter is 47.7 mm (1.878 in.) and
inside diameter is 32.6 mm (1.283 in.).
²Race outer diameter is 53.6 mm (2.110 in.) and in-
side diameter is 30.6 mm (1.205 in.).
(36) Rotate front of transmission case downward
and install assembled planetary gear/forward-direct
clutch (Fig. 29).
Fig. 25 Installing Planetary Ring Gear Race
Fig. 26 Aligning Forward-Direct Clutch Splines
Fig. 27 Installing Front Planetary Ring Gear
Fig. 28 Installing Ring Gear Bearing And Race
ART: j8921-696; SIZE (3) = 3-1/2h x 3-1/2w
Fig. 29 Installing Front Planetary And Forward-
Direct Clutch Assembly
JAW-4 TRANSMISSION OVERHAUL 21 - 261

(37) Check clearance between sun gear input drum
and direct clutch drum (Fig. 30). Clearance should be
9.8 - 11.8 mm (0.386 - 0.465 in.). If clearance is in-
correct, planetary gear/forward-direct clutch assem-
bly is not seated or is improperly assembled. Remove,
and correct if necessary.
(38) Coat thrust bearing and race assembly with
petroleum jelly and install it on clutch shaft. Bearing
faces up and toward case front as shown (Fig. 31).
Verify bearing/race size. Bearing and race outer di-
ameter is 47.8 mm (1.882 in.) and inside diameter is
33.6 mm (1.301 in.).
(39) Assemble second coast brake piston compo-
nents (Fig. 32).(40) Install assembled second coast brake piston in
case.
(41) Install replacement seals on second coast
brake piston cover and install cover in case.
(42) Install second coast brake piston snap ring
with snap ring plier tool (Fig. 33).
(43) Check second coast brake piston stroke as fol-
lows:
(a) Make reference mark on brake piston rod
(Fig. 34).
(b) Apply 57-114 psi air pressure through feed
hole (Fig. 34). Alternately apply and release air
pressure to operate piston.
(c) Check stroke with gauge 7552 (Fig. 35).
(d) If stroke length is incorrect, piston, cover or
snap ring is not seated. Reassemble and check
stroke again if necessary.
(44) Coat thrust race and tabbed washer with pe-
troleum jelly and install them on overdrive support
(Fig. 36). Verify race size. Race outer diameter is 50.9
mm (2.004 in.) and inside diameter is 36.2 mm (1.426
in.).
Fig. 30 Checking Input Drum-To-Direct Clutch Drum
Clearance
Fig. 31 Installing Clutch Shaft Thrust Bearing And
Race Assembly
Fig. 32 Assembling Second Coast Brake Piston
Fig. 33 Installing Second Coast Brake Piston Snap
Ring
21 - 262 AW-4 TRANSMISSION OVERHAULJ

(45) Install overdrive support in case. Use two long
bolts to help align and guide support into position
(Fig. 37).
(46) Install overdrive support snap ring with Snap
Ring Plier Tool 7540 (Fig. 38). Chamfered side of
snap ring faces up and toward case front.Snap ring
ends must be aligned with case opening with
ring ends approximately 24 mm (0.94 in.) from
centerline of case opening.
(47) Install and tighten overdrive support bolts to
25 Nzm (19 ft-lbs) torque (Fig. 39).
(48) Check output shaft end play with dial indica-
tor (Fig. 40). End play should be 0.27 - 0.86 mm
(0.0106 - 0.0339 in.).(49) If output shaft end play is incorrect, one or
more of installed components is not seated. Reassem-
ble as necessary and check end play again.
(50) Install overdrive clutch pack (Fig. 41). Install
thickest clutch plate first. Rounded edge of plate
faces up. Install first disc followed by another plate
until correct number of discs-plates are installed. In-
stall four discs and three plates.
(51) Install stepped ring retainer plate with flat
side facing disc. Then install brake pack snap ring
(Fig. 42).
Fig. 36 Installing Overdrive Support Thrust Race
And Washer
Fig. 37 Installing Overdrive Support
Fig. 34 Marking Brake Piston Rod
Fig. 35 Checking Second Coast Brake Piston Stroke
JAW-4 TRANSMISSION OVERHAUL 21 - 263

OPERATING RANGES
NP231 operating ranges are: 2-wheel drive high; 4-
wheel drive high and 4-wheel drive low (Fig. 2).
2-wheel drive range is for use on all surfaces. The
4-wheel drive high and low ranges are undifferenti-
ated and should only be used on unpaved, low trac-
tion surfaces only.
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 (Fig. 2). Range po-
sitions are marked on the shifter bezel cover plate. A
front axle disconnect mechanism is only used on cer-
tain models.
TRANSFER CASE IDENTIFICATION
A circular ID tag is attached to the rear case of
each NP231 transfer case (Fig. 3). 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 8-
10-92 would represent August 10, 1992.
TRANSFER CASE LUBRICANT
Recommended Lubricant
Use Mopar Dexron II, or ATF Plus, type 7176 au-
tomatic transmission fluid in the NP231 transfer
case.
Lubricant Capacity
Approximate refill lubricant capacity is 1.54 liters
(3.25 pints) for YJ and 1.04 liters (2.2 pints) for XJ.
Fill Level
The correct fill level is to the bottom edge of the fill
plug hole. The vehicle must be level in order to en-
sure an accurate fluid level check.
Fig. 2 NP231 Shift Pattern
Fig. 3 Transfer Case Identification Tag
JNP231 TRANSFER CASE 21 - 273

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.
(11) Support transfer case with transmission jack.
(12) Remove nuts attaching transfer case to trans-
mission.
(13) Secure transfer case to jack with chains.
(14) Pull transfer case and jack rearward to disen-
gage transfer case.
(15) Remove transfer case from under vehicle.
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) Connect vehicle speed sensor wires, and vent hose.
(6) Align and connect propeller shafts. Tighten
shaft attaching bolts to 19 Nzm (170 in. lbs.) torque.
(7) Fill transfer case with Mopar ATF Plus, or
Dexron II automatic transmission fluid.
(8) Install rear crossmember, or skid plate. Tighten
crossmember bolts to 41 Nzm (30 ft. lbs.) torque.
(9) Remove transmission jack and transmission
support stand.
(10) Connect transfer case range lever to linkage rod.
Fig. 7 Installing Shift Lever SpacerÐXJ
Fig. 8 Shift LinkageÐYJ
Fig. 9 Shift LinkageÐXJ
21 - 276 NP231 TRANSFER CASEJ