(11) Push and hold differential case to ring gear
side of the housing and record dial indicator reading
(Fig. 19).
(12) Add 0.152 mm (0.006 in.) to the zero end play
total. This new total represents the thickness of
shims to compress or preload the new bearings when
the differential is installed.
(13) Rotate dial indicator out of the way on the
pilot stud.
(14) Remove differential case and dummy bearings
from the housing.
(15) Install the pinion gear in the housing. Install
the pinion yoke and establish the correct pinion
rotating torque.
(16) Install differential case and Dummy Bearings
D-348 in the housing.
(17) Install a single dummy shim in the ring gear
side. Install bearing caps and tighten bolts snug.
(18) Seat ring gear side dummy bearing (Fig. 17).
(19) Position the dial indicator plunger on a flat
surface between the ring gear bolt heads.
(20) Push and hold differential case toward pinion
gear and zero dial indicator (Fig. 20).
(21) Push and hold differential case to ring gear
side of the housing and record dial indicator reading
(Fig. 21). Add dummy shim thickness to this reading.
This will be the total shim thickness to achieve zero
backlash.
(22) Subtract 0.076 mm (0.003 in.) from the dial
indicator reading to compensate for backlash between
ring and pinion gears. This total is the thickness
shim required to achieve proper backlash.
(23) Subtract the backlash shim thickness from
the total preload shim thickness. The remainder is
the shim thickness required on the pinion side of the
axle housing.(24) Rotate dial indicator out of the way on pilot
stud.
(25) Remove differential case and dummy bearings
from the housing.
(26) Install side bearings and cups on differential
case.
(27) Install spreader W-129-B with Adapter Set
6987 on the housing and spread axle opening enough
to receive differential case.
CAUTION: Never spread the differential housing
over 0.34 mm (0.013 in.). If the housing is over-
spread, it could be distorted or damaged.
Fig. 19 DIFFERENTIAL RING GEAR SIDE
1 - DIAL INDICATOR
2 - DIFFERENTIAL HOUSING
Fig. 20 DIFFERENTIAL PINION GEAR SIDE
1 - DIAL INDICATOR
2 - PINION GEAR
3 - RING GEAR
Fig. 21 DIFFERENTIAL RING GEAR SIDE
1 - DIAL INDICATOR
2 - PINION GEAR
3 - RING GEAR
3 - 30 FRONT AXLE - 186FIAKJ
FRONT AXLE - 186FIA (Continued)
DIFFERENTIAL BEARING PRELOAD CHECK
The final check on the differential assembly before
installing the axles, is torque to rotate pinion and
differential combined. This will verify the correct dif-
ferential bearing preload.
Torque to rotate the differential and pinion is the
torque to rotate the pinion plus:Gear Ratio 3.73....0.45-0.75 N´m (3.9-6.6 in. lbs.)
Gear Ratio 3.91....0.43-0.72 N´m (3.8-6.4 in. lbs.)
Gear Ratio 4.10....0.41-0.69 N´m (3.6-6.0 in. lbs.)
SPECIFICATIONS - FRONT AXLE
SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.73, 3.92, 4.10
Ring Gear Diameter 186 mm (7.33 in.)
Ring Gear Backlash 0.12-0.20 mm (0.005-0.008 in.)
Pinion Gear Standard Depth 92.1 mm (3.625 in.)
Pinion Bearing Preload 1.69-2.82 N´m (15-25 in. lbs.)
Differential Bearing Preload
Added To Pinion Torque To Rotate
Gear Ratio 3.73 0.45-0.75 N´m (3.9-6.6 in. lbs.)
Gear Ratio 3.92 0.43-0.72 N´m (3.8-6.4 in. lbs.)
Gear Ratio 4.10 0.41-0.69 N´m (3.6-6.0 in. lbs.)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Ring Gear Bolts 95-122 70-90 -
Differential Bearing Cap
Bolts54-67 39-50 -
Differential Cover Bolts 19-26 14-19 -
Pinion Nut 217-352 160-260 -
Left Axle Bracket Bolts 61 45 -
Front Axle Bracket Bolts 61 45 -
Right Axle Bracket Bolts 88 65 -
Axle Brackets To Frame
Bolts88 65 -
KJFRONT AXLE - 186FIA 3 - 33
FRONT AXLE - 186FIA (Continued)
INSTALLATION
(1) Apply a light coat of lubricant on the lip of the
shaft seal.
(2) Installnewshaft seal with Installer 8806 and
Handle C-4171 (Fig. 28).
(3) Install right axle shaft if removed.
(4) Install half shaft.
AXLE BEARINGS
REMOVAL
(1) Remove half shaft.
(2) Remove axle shaft for right side seal removal.
(3) Remove shaft seal with Remover 7794-A and a
slide hammer.
(4) Remove shaft bearing with Remover 7794-A
and a slide hammer (Fig. 29).
INSTALLATION
(1) Installnewshaft bearing with Installer 8805
and Handle C-4171.
(2) Apply a light coat of lubricant on the lip of the
shaft seal.
(3) Installnewshaft seal with an appropriate
installer.
(4) Install right axle shaft if removed.
(5) Install half shaft.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove brake calipers and rotors, refer to 5
Brakes for procedures.
(4) Mark propeller shaft and pinion companion
flange for installation reference.
(5) Remove propeller shaft from the pinion com-
panion flange.
(6) Rotate pinion gear a minimum of ten times and
verify the pinion rotates smoothly.
(7) Record the torque to rotate the pinion gear
(Fig. 30) with a inch pound torque wrench.
Fig. 28 SEAL INSTALLER
1 - SEAL BORE
2 - INSTALLER
Fig. 29 SHAFT BEARING REMOVER
1 - SHAFT BEARING
2 - REMOVER
Fig. 30 PINION ROTATING TORQUE
1 - PINION COMPANION FLANGE
2 - TORQUE WRENCH
3 - 38 FRONT AXLE - 186FIAKJ
AXLE SHAFT SEALS (Continued)
(8) Using a short piece of pipe and Spanner
Wrench 6958 to hold the pinion companion flange
(Fig. 31) and remove the pinion nut.
(9) Remove pinion companion flange (Fig. 32) with
Remover C-452 and Spanner Wrench 6958.
(10) Remove pinion seal with Remover 7794-A and
a slide hammer (Fig. 33).
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with an appropriate
installer (Fig. 34).
(2) Install pinion companion flange on the pinion
gear with Installer W-162-D, Cup 8109 and Wrench
6958.CAUTION: Do not exceed the minimum tightening
torque 216 N´m (160 ft. lbs.) while installing pinion
nut at this point. Damage to collapsible spacer or
bearings may result.
(3) Install anewnut on the pinion gear.Tighten
the nut only enough to remove the shaft end
play.
CAUTION: Never loosen pinion nut to decrease pin-
ion rotating torque and never exceed specified pre-
load torque. If preload torque or rotating torque is
exceeded a new collapsible spacer must be
installed.
Fig. 31 PINION FLANGE NUT
1 - SPANNER WRENCH
2 - PINION COMPANION FLANGE
Fig. 32 PINION FLANGE REMOVER
1 - SPANNER WRENCH
2 - REMOVER
Fig. 33 PINION SEAL
1 - REMOVER
2 - SLIDE HAMMER
3 - PINION SEAL
Fig. 34 PINION SEAL INSTALLATION
1 - HANDLE
2 - INSTALLER
KJFRONT AXLE - 186FIA 3 - 39
PINION SEAL (Continued)
(4) Rotate pinion a minimum of ten time and ver-
ify pinion rotates smoothly. Rotate the pinion shaft
with an inch pound torque wrench. Rotating torque
should be equal to the reading recorded during
removal plus 0.56 N´m (5 in. lbs.) (Fig. 35).
(5) If the rotating torque is low, use Spanner
Wrench 6958 to hold the pinion companion flange
and tighten the pinion shaft nut in 6.8 N´m (5 ft.
lbs.) increments until proper rotating torque is
achieved.
CAUTION: If maximum tightening torque is reached
prior to reaching the required rotating torque, the
collapsible spacer may have been damaged.
Replace the collapsible spacer.
(6) Install propeller shaft with installation refer-
ence marks aligned.
(7) Fill differential with gear lubricant.
(8) Install brake rotors and calipers.
(9) Install wheel and tire assemblies.
(10) Lower the vehicle.
DIFFERENTIAL
REMOVAL
(1) Remove axle from the vehicle.
(2) Remove differential housing cover (Fig. 36).
(3) Push right axle shaft out of side gear (Fig. 37)
and remove the shaft.
(4) Mark differential bearing caps for installation
reference.
(5) Loosen the bearing cap bolts.
Fig. 35 PINION ROTATING TORQUE
1 - PINION COMPANION FLANGE
2 - TORQUE WRENCHFig. 36 DIFFERENTIAL COVER
1 - COVER
2 - VENT TUBE
Fig. 37 RIGHT SHAFT IN SIDE GEAR
1 - AXLE SHAFT
2 - SCREWDRIVER
3 - SIDE GEAR
3 - 40 FRONT AXLE - 186FIAKJ
PINION SEAL (Continued)
(5) Apply a light coating of gear lubricant on the
lip of pinion seal and intall seal with an appropriate
installer (Fig. 55).
(6) Install rear pinion bearing and oil slinger/depth
shim onto the pinion shaft with Installer 6448 and a
press (Fig. 56).(7) Install anewcollapsible spacer on pinion shaft
and install the pinion into the housing (Fig. 57).
(8) Install pinion companion flange, with Installer
W-162-D, Cup 8109 and Spanner Wrench 6958.
(9) Install pinion anewnut onto the pinion gear
and tighten the nut to 216 N´m (160 ft. lbs.).Do not
over-tighten.
CAUTION: Never loosen pinion gear nut to decrease
pinion rotating torque and never exceed specified
preload torque. If preload torque is exceeded a new
collapsible spacer must be installed.
Fig. 55 PINION SEAL
1 - HANDLE
2 - INSTALLER
Fig. 56 REAR PINION BEARING
1 - INSTALLER
2 - OIL SLINGER
3 - PINION GEAR
4 - REAR PINION BEARING
5 - PRESS
Fig. 57 COLLAPSIBLE PRELOAD SPACER
1 - COLLAPSIBLE SPACER
2 - SHOULDER
3 - PINION GEAR
4 - OIL SLINGER
5 - REAR BEARING
KJFRONT AXLE - 186FIA 3 - 47
PINION GEAR/RING GEAR (Continued)
(10) Use Flange Wrench 6958, a length of 1 in.
pipe and a torque wrench set at 678 N´m (500 ft. lbs.)
and crush collapsible spacer until bearing end play is
taken up (Fig. 58).
(11) Slowly tighten the nut in 6.8 N´m (5 ft. lb.)
increments until the required rotating torque is
achieved. Measure the rotating torque frequently to
avoid over crushing the collapsible spacer (Fig. 59).
(12) Rotate the pinion a minimum of ten times.
Verify pinion rotates smoothly and check rotating
torque with an inch pound torque wrench (Fig. 59).
Pinion gear rotating torque is:
²Original Bearings: 1 to 2.25 N´m (10 to 20 in.
lbs.).
²New Bearings: 1.69 to 2.82 N´m (15 to 25 in.
lbs.).
(13) Invert the differential case and start two ring
gear bolts. This will provide case-to-ring gear bolt
hole alignment.
(14) Invert the differential case in the vise. Install
newring gear bolts and alternately tighten to 108
N´m (80 ft. lbs.) (Fig. 60).
CAUTION: Never reuse the ring gear bolts. The
bolts can fracture causing extensive damage.
(15) Install differential in housing and verify dif-
ferential bearing preload, gear mesh and contact pat-
tern. Refer to Adjustment for procedure.
(16) Install differential cover and fill with gear
lubricant.
(17) Install propeller shaft with reference marks
aligned.
(18) Remove supports and lower vehicle.
Fig. 58 PINION FLANGE NUT
1 - SPANNER WRENCH
2 - PINION COMPANION FLANGE
Fig. 59 PINION ROTATING TORQUE
1 - PINION COMPANION FLANGE
2 - TORQUE WRENCH
Fig. 60 RING GEAR BOLTS
1 - TORQUE WRENCH
2 - RING GEAR BOLTS
3 - RING GEAR
4 - DIFFERENTIAL CASE
3 - 48 FRONT AXLE - 186FIAKJ
PINION GEAR/RING GEAR (Continued)
rear propeller shaft is connected to the pinion gear
which rotates the differential through the gear mesh
with the ring gear bolted to the differential case. The
engine power is transmitted to the axle shafts
through the pinion mate and side gears. The side
gears are splined to the axle shafts.
STANDARD DIFFERENTIAL
During straight-ahead driving, the differential pin-
ion gears do not rotate on the pinion mate shaft. This
occurs because input torque applied to the gears is
divided and distributed equally between the two side
gears. As a result, the pinion gears revolve with the
pinion mate shaft but do not rotate around it (Fig. 2).
When turning corners, the outside wheel must
travel a greater distance than the inside wheel to
complete a turn. The difference must be compensated
for to prevent the tires from scuffing and skidding
through turns. To accomplish this, the differential
allows the axle shafts to turn at unequal speeds (Fig.
3). In this instance, the input torque applied to the
pinion gears is not divided equally. The pinion gears
now rotate around the pinion mate shaft in opposite
directions. This allows the side gear and axle shaft
attached to the outside wheel to rotate at a faster
speed.
TRAC-LOKŸ DIFFERENTIAL
The Trac-lokŸ clutches are engaged by two concur-
rent forces. The first being the preload force exerted
through Belleville spring washers within the clutch
packs. The second is the separating forces generated
by the side gears as torque is applied through the
ring gear (Fig. 4).
Fig. 2 DIFFERENTIAL-STRAIGHT AHEAD DRIVING
1 - IN STRAIGHT AHEAD DRIVING EACH WHEEL ROTATES AT
100% OF CASE SPEED
2 - PINION GEAR
3 - SIDE GEAR
4 - PINION GEARS ROTATE WITH CASE
Fig. 3 DIFFERENTIAL-ON TURNS
1 - PINION GEARS ROTATE ON PINION SHAFT
Fig. 4 TRAC-LOK DIFFERENTIAL
1 - CASE
2 - RING GEAR
3 - DRIVE PINION
4 - PINION GEAR
5 - MATE SHAFT
6 - CLUTCH PACK
7 - SIDE GEAR
8 - CLUTCH PACK
3 - 50 REAR AXLE - 198RBIKJ
REAR AXLE - 198RBI (Continued)