Jeep cherokee 2000 Service Manual page 52

3 - 16 TUBE, 181, AND 186 FBI AXLE
DESCRIPTION AND OPERATION
181 FBI AXLE. . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
186 FBI AXLE. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
LUBRICANT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
STANDARD DIFFERENTIAL . . . . . . . . . . . . . . . . . 18
DIAGNOSIS AND TESTING
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . 19
GEAR NOISE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
BEARING NOISE . . . . . . . . . . . . . . . . . . . . . . . . . 21
LOW SPEED KNOCK . . . . . . . . . . . . . . . . . . . . . . 21
VIBRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
DRIVELINE SNAP . . . . . . . . . . . . . . . . . . . . . . . . 21
SERVICE PROCEDURES
LUBRICANT CHANGE . . . . . . . . . . . . . . . . . . . . . 21
REMOVAL AND INSTALLATION
DRIVE AXLE ASSEMBLY . . . . . . . . . . . . . . . . . . . 22
TUBE AXLE ASSEMBLY . . . . . . . . . . . . . . . . . . . . 23
AXLE SHAFT-CARDAN U-JOINT . . . . . . . . . . . . 23
181 FBI PINION SHAFT SEAL . . . . . . . . . . . . . . . 24
186 FBI PINION SHAFT SEAL . . . . . . . . . . . . . . . 26
COLLAPSIBLE SPACER. . . . . . . . . . . . . . . . . . . . 27
HUB BEARING AND AXLE SHAFT . . . . . . . . . . . . 30
STEERING KNUCKLE AND BALL STUDS. . . . . . . 31
AXLE BUSHING REPLACEMENT . . . . . . . . . . . . . 33
DIFFERENTIAL . . . . . . . . . . . . . . . . . . . . . . . . . . 33
DESCRIPTION AND OPERATION
181 FBI AXLE
DESCRIPTION
The 181 Front Beam-design Iron (FBI) axle con-
sists of a cast iron differential housing with axle
shaft tubes extending from either side. The tubes are
pressed into the differential housing and welded.
The integral type housing, hypoid gear design has
the centerline of the pinion set above the centerline
of the ring gear.
The axle has a fitting for a vent hose used to
relieve internal pressure caused by lubricant vapor-
ization and internal expansion.
The axles are equipped with semi-floating axle
shafts, meaning that loads are supported by the hub
bearings. The axle shafts are retained by nuts at the
hub bearings. The hub bearings are bolted to the
steering knuckle at the outboard end of the axle tube
yoke. The hub bearings are serviced as an assembly.
TUBE, 181, AND 186 FBI AXLE
TABLE OF CONTENTS
page
DIFFERENTIAL SIDE BEARINGS . . . . . . . . . . . . . 36
AXLE SHAFT OIL SEAL . . . . . . . . . . . . . . . . . . . . 36
181 FBI PINION . . . . . . . . . . . . . . . . . . . . . . . . . . 36
186 FBI PINION . . . . . . . . . . . . . . . . . . . . . . . . . . 41
RING GEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
DISASSEMBLY AND ASSEMBLY
STANDARD DIFFERENTIAL . . . . . . . . . . . . . . . . . 46
FINAL ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 47
CLEANING AND INSPECTION
CARDAN U-JOINT . . . . . . . . . . . . . . . . . . . . . . . . 47
AXLE COMPONENTS . . . . . . . . . . . . . . . . . . . . . 47
ADJUSTMENTS
181 FBI PINION GEAR DEPTH. . . . . . . . . . . . . . . 48
186 FBI PINION GEAR DEPTH. . . . . . . . . . . . . . . 50
181 FBI DIFFERENTIAL BEARING PRELOAD
AND GEAR BACKLASH . . . . . . . . . . . . . . . . . . 52
186 FBI DIFFERENTIAL BEARING PRELOAD
AND GEAR BACKLASH . . . . . . . . . . . . . . . . . . 56
GEAR CONTACT PATTERN ANALYSIS . . . . . . . . 59
SPECIFICATIONS
181 FBI AXLE. . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
186 FBI AXLE. . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
TORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
SPECIAL TOOLS
181 and 186 FBI AXLE . . . . . . . . . . . . . . . . . . . . . 61
For vehicles with ABS brakes, the ABS wheel
speed sensors are attached to the knuckle assem-
blies. The tone rings for the ABS system are pressed
onto the axle shaft. Do not damage ABS tone
wheel or the sensor when removing axle shafts.
The stamped steel cover provides a means for
inspection and servicing the differential.
The 181 FBI axle has the assembly part number
and gear ratio listed on a tag. The tag is attached to
the housing cover by a cover bolt. Build date identi-
fication codes are stamped on the cover side of the
axle shaft tube.
The differential case is a one-piece design. The dif-
ferential pinion mate shaft is retained with a roll
pin. Differential bearing preload and ring gear back-
lash is adjusted by the use of shims (select thick-
ness). The shims are located between the differential
bearing cones and case. Pinion bearing preload is set
and maintained by the use of shims (select thick-
ness).
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