Jeep Wrangler 1997 Manual - page 1074
NV231 TRANSFER CASE
INDEX
page
page
GENERAL INFORMATION
NV231 TRANSFER CASE . . . . . . . . . . . . . . . . . 167
RECOMMENDED LUBRICANT AND
FILL LEVEL . . . . . . . . . . . . . . . . . . . . . . . . . . 167
TRANSFER CASE IDENTIFICATION . . . . . . . . . 167
DIAGNOSIS AND TESTING
NV231 DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . 168
REMOVAL AND INSTALLATION
FRONT OUTPUT SHAFT SEAL . . . . . . . . . . . . 172
SHIFT LEVER . . . . . . . . . . . . . . . . . . . . . . . . . . 170
SPEEDOMETER . . . . . . . . . . . . . . . . . . . . . . . . 170
TRANSFER CASE . . . . . . . . . . . . . . . . . . . . . . 170
DISASSEMBLY AND ASSEMBLY
NV231 TRANSFER CASE . . . . . . . . . . . . . . . . . 172
CLEANING AND INSPECTION
NV231 TRANSFER CASE . . . . . . . . . . . . . . . . . 188
ADJUSTMENTS
SHIFT LINKAGE ADJUSTMENT . . . . . . . . . . . . 190
SPECIFICATIONS
TORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
SPECIAL TOOLS
SPECIAL TOOLS—NV231 . . . . . . . . . . . . . . . . 192
GENERAL INFORMATION
NV231 TRANSFER CASE
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 input gear is splined to the transmission output
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 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 synchronizer 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
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.
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.
RECOMMENDED LUBRICANT AND FILL LEVEL
Recommended lubricant for the NV231 transfer
case is Mopar
t
Dexron II, or ATF Plus. Approximate
lubricant fill capacity is 1.2 liters (2.5 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.
Fig. 1 Fill/Drain Plug And I.D. Tag Locations
21 - 168
TRANSMISSION AND TRANSFER CASE
TJ