1995 JEEP YJ torque

(15) Position park lock rod bracket on case and
tighten bracket attaching bolts to 10 Nzm (7 ft. lbs.)
torque (Fig. 12).
(16) Verify park lock operation. Move shift sector
to Park position. Park pawl should be firmly engaged
(locked) in planetary ring gear (Fig. 13).(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.
Fig. 12 Installing Park Rod Bracket
Fig. 13 Checking Park Pawl Engagement
Fig. 14 Installing No. 1 One-Way Clutch
Fig. 15 Installing Second Brake Pack
21 - 268 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.
Fig. 37 Installing Overdrive Support
Fig. 38 Installing Overdrive Support Snap Ring
Fig. 39 Installing Overdrive Support Bolts
Fig. 40 Checking Output Shaft End Play
21 - 274 AW-4 TRANSMISSION OVERHAULJ

(a) Install 4.0 mm (0.157 in.) thick plate first.
Rounded edge of plate must face upward.
(b) Install a disc followed by a plate until the re-
quired number of discs and plates are installed. Be
sure to install the stepped plate last with the flat
side of the plate facing the disc (Fig. 51).
(c) Confirm that four discs and three plates have
been installed.
(64) Install clutch pack snap ring (Fig. 52).(65) Coat thrust bearing race with petroleum jelly
and install it in oil pump (Fig. 53). Bearing race
outer diameter is 47.2 mm (1.858 in.) and inside di-
ameter is 28.1 mm (1.106 in.).
(66) Lubricate and install replacement O-ring on
oil pump body.
(67) Install oil pump in case. Align pump and case
bolt holes and carefully ease pump into place (Fig.
54).
CAUTION: Do not use force to seat the pump. The
seal rings on the stator shaft could be damaged if
they bind or stick to the direct clutch drum.
(68) Tighten oil pump bolts to 22 Nzm (16 ft. lbs.)
torque.
Fig. 49 Installing Overdrive Planetary And Clutch
Assembly
Fig. 50 Installing Input Shaft Thrust Bearing And
Race Assembly
Fig. 51 Installing Overdrive Clutch Pack
Fig. 52 Installing Clutch Pack Snap Ring
JAW-4 TRANSMISSION OVERHAUL 21 - 277

(73) Assemble and install accumulator pistons and
springs (Fig. 57).
(74) Install new check ball body and spring (Fig.
58).
(75) Position valve body on case (Fig. 59).(76) Install detent spring (Fig. 59).
(77) Align manual valve, detent spring and shift
sector (Fig. 59).
(78) Connect transmission throttle cable to throttle
valve cam (Fig. 60).
(79) Install and tighten valve body-to-case bolts to
10 Nzm (7 ft. lbs.) torque.
(80) Connect valve body solenoid wires to solenoids
(Fig. 61).
(81) Install new O-ring on solenoid harness
adapter and secure adapter to case.
(82) Install valve body oil tubes (Fig. 62). Tap
tubes into place with a plastic mallet. Be sure the
flanged tube ends and straight tube ends are in-
stalled as shown.
Fig. 57 Accumulator Piston And Spring Installation
Fig. 58 Installing Check Ball Body And Spring
Fig. 59 Aligning Manual Valve, Shift Sector And
Detent Spring
Fig. 60 Connecting Transmission Throttle Cable
JAW-4 TRANSMISSION OVERHAUL 21 - 279

(83) Install new gaskets on oil screen and install
screen on valve body. Tighten screen bolts to 10 Nzm
(7 ft. lbs.) torque.
(84) Install magnet in oil pan. Be sure magnet
does not interfere with valve body oil tubes.
(85) Apply Loctite 599 to sealing surface of oil pan.
Sealer bead should be at least 3 mm (1/8 in.) wide.
Install pan on case and tighten pan bolts to 7 Nzm
(65 in. lbs.) torque.
(86) Install transmission speed sensor rotor and
key on output shaft (Fig. 63).
(87) Install spacer and speedometer drive gear on
output shaft. Then install retaining snap ring (Fig.
64).
(88) Apply bead of Loctite 599 sealer to sealing
surface at rear of case (Fig. 65).(89) Install adapter housing on transmission.
Tighten adapter bolts to 34 Nzm (25 ft. lbs.) torque.
(90) Install transmission speed sensor (Fig. 66).
Tighten sensor bolt to 7.4 Nzm (65 in. lbs.) torque
and connect sensor wire harness connector.
(91) Install converter housing (Fig. 67). Tighten 12
mm diameter housing bolts to 57 Nzm (42 ft. lbs.)
torque. Tighten 10 mm diameter housing bolts to 34
Nzm (25 ft. lbs.) torque.
(92) Install transmission shift lever on manual
valve shaft. Do not install lever attaching nut at this
time.
(93) Move transmission shift lever fully rearward.
Then move lever two detent positions forward.
Fig. 61 Connecting Valve Body Solenoid Wires
Fig. 62 Installing Valve Body Oil Tubes
Fig. 63 Installing Transmission Speed Sensor Rotor
And Key
Fig. 64 Installing Spacer And Speedometer Drive
Gear
21 - 280 AW-4 TRANSMISSION OVERHAULJ

(94) Mount park/neutral position switch on manual
valve shaft and tighten switch adjusting bolt just
enough to keep switch from moving (Fig. 68).
(95) Install park/neutral position switch tabbed
washer and retaining nut (Fig. 68). Tighten nut to
6.9 Nzm (61 in. lbs.) torque, but do not bend any of
the washer tabs against the nut at this time.
(96) Align park/neutral position switch standard
line with groove or flat on manual shaft (Fig. 68).(97) Tighten park/neutral position switch adjusting
bolt to 13 Nzm (9 ft. lbs.) torque.
(98) Install transmission shift lever on manual
valve shaft. Tighten lever attaching nut to 16 Nzm
(12 ft. lbs.) torque.
Fig. 65 Applying Sealer To Case Rear Flange
Fig. 66 Installing Transmission Speed Sensor
Fig. 67 Installing Converter Housing
Fig. 68 Park/Neutral Position Switch Installation/
Adjustment
JAW-4 TRANSMISSION OVERHAUL 21 - 281

(99) Install retaining clamp for wire harness and
throttle cable (Fig. 69).
(100) Install torque converter.
(101) Verify that converter is seated by measuring
distance between converter housing flange and one of
the converter mounting pads (Fig. 70). Use straight-
edge and vernier calipers to measure distance. On
6-cyl. transmissions, distance should be 16.5 mm
(0.650 in.).
(102) Secure converter in transmission with
C-clamp or metal strapping. Do this before mounting
transmission on jack or moving transmission under
vehicle.(103) Install lower half of transmission fill tube (in-
stall upper half after transmission is in vehicle).
CAUTION: The transmission cooler and lines must
be reverse flushed if overhaul corrected a malfunc-
tion that generated sludge, metal particles, or
clutch friction material. The torque converter should
also be replaced if contaminated by the same mal-
function. Debris and residue not flushed from the
cooler and lines will flow back into the transmission
and converter. The result will be a repeat failure and
shop comeback.
Fig. 69 Installing Cable/Harness Clamps
Fig. 70 Checking Converter Installation
21 - 282 AW-4 TRANSMISSION OVERHAULJ

NP231 TRANSFER CASE
INDEX
page page
General Information....................... 283
Overhaul Cleaning and Inspection............ 294
Shift Lever Installation (XJ)................. 286
Shift Lever Installation (YJ)................. 286
Shift Lever Removal (XJ)................... 286
Shift Lever Removal (YJ)................... 286
Shift Linkage Adjustment................... 286Speedometer Service..................... 287
Transfer Case Assembly................... 294
Transfer Case Disassembly and Overhaul...... 289
Transfer Case Identification................. 284
Transfer Case Installation.................. 288
Transfer Case Lubricant and Fill Level......... 284
Transfer Case Removal.................... 287
GENERAL INFORMATION
The NP231 is a part-time transfer case with a low
range reduction gear system (Fig. 1). The NP231 has
three operating ranges plus a Neutral position. A low
range system provides a reduction ratio for increased
low speed torque capability.The NP231 is the Command Trac transfer case. It
is used in XJ and YJ models. Two versions are used.
One version retains the synchronizer components
used in previous models. A newly introduced version
is not equipped with synchro components.
Fig. 1 NP231 Transfer Case
JNP231 TRANSFER CASE 21 - 283