Jeep cherokee 2000 Service Manual page 1254

21 - 346 NV231 TRANSFER CASE
DESCRIPTION AND OPERATION
NV231 TRANSFER CASE. . . . . . . . . . . . . . . . . . 346
LUBRICANT AND FILL LEVEL . . . . . . . . . . . . . . 347
DIAGNOSIS AND TESTING
NV231 DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . . 347
REMOVAL AND INSTALLATION
TRANSFER CASE . . . . . . . . . . . . . . . . . . . . . . . 348
SHIFT LEVER . . . . . . . . . . . . . . . . . . . . . . . . . . 349
SPEEDOMETER. . . . . . . . . . . . . . . . . . . . . . . . . 350
FRONT OUTPUT SHAFT SEAL . . . . . . . . . . . . . 350
DESCRIPTION AND OPERATION
NV231 TRANSFER CASE
DESCRIPTION
The NV231 is a part-time transfer case with a low
range reduction gear system. The NV231 has three
operating ranges plus a Neutral position. A low range
system provides a reduction ratio for increased low
speed torque capability.
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
Transfer case operating ranges are:
• 2WD (2-wheel drive)
• 4x4 (4-wheel drive)
• 4 Lo (4-wheel drive low range
The 2WD range is for use on any road surface at
any time.
The 4x4 and 4 Lo ranges are for off road use only.
They are not for use on hard surface roads. The only
exception being when the road surface is wet or slip-
pery or covered by ice and snow.
The low range reduction gear system is operative
in 4 Lo range only. This range is for extra pulling
power in off road situations. Low range reduction
ratio is 2.72:1.
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.
NV231 TRANSFER CASE
TABLE OF CONTENTS
page
DISASSEMBLY AND ASSEMBLY
NV231 TRANSFER CASE. . . . . . . . . . . . . . . . . . 351
CLEANING AND INSPECTION
NV231 TRANSFER CASE. . . . . . . . . . . . . . . . . . 369
ADJUSTMENTS
SHIFT LINKAGE ADJUSTMENT . . . . . . . . . . . . . 372
SPECIFICATIONS
TORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
SPECIAL TOOLS
NV231 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
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.
Fig. 1 Fill/Drain Plug And I. D. Tag Locations
1 - I. D. TAG
2 - FILL PLUG
3 - DRAIN PLUG
OPERATION
The input gear is splined to the transmission out-
put shaft. The input gear drives the mainshaft
through the planetary assembly and range hub. The
front output shaft is operated by a drive chain that
connects the shaft to a drive sprocket on the main-
shaft. The drive sprocket is engaged/disengaged by
the mode fork, which operates the mode sleeve and
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