Dodge Durango (DN). Manual - part 235

tighten the forcing screw in order to install the pin-
ion gears.

(12) Tighten forcing screw to 122 N·m (90 ft. lbs.)

maximum to compress the Belleville springs.

(13) Lubricate and install thrust washers behind

pinion gears and align washers with a small screw
driver. Insert mate shaft into each pinion gear to ver-
ify alignment.

(14) Remove Forcing Screw C-4487-2, Step Plate

8139-2, and Threaded Adapter 8139-1.

(15) Install pinion gear mate shaft and align holes

in shaft and case.

(16) Install the pinion mate shaft lock screw finger

tight to hold shaft during differential installation.

(17) Lubricate all differential components with

hypoid gear lubricant.

CLEANING AND INSPECTION

8 1/4 AND 9 1/4 AXLES

Wash differential components with cleaning solvent

and dry with compressed air. Do not steam clean
the differential components.

Wash bearings with solvent and towel dry, or dry

with compressed air. DO NOT spin bearings with
compressed

air.

Cup

and

bearing

must

replaced as matched sets only.

Clean axle tubes and oil channels in housing.
Inspect for:

• Smooth appearance with no broken/dented sur-

faces on the bearing rollers or the roller contact sur-
faces.

• Bearing cups must not be distorted or cracked.

• Machined surfaces should be smooth and with-

out any raised edges.

• Raised metal on shoulders of cup bores should

be removed with a hand stone.

• Wear and damage to pinion mate shaft, differen-

tial pinions, side gears and thrust washers. Replace
as a matched set only.

• Ring gear and pinion for worn and chipped

teeth.

• Ring gear for damaged bolt threads. Replaced as

a matched set only.

• Pinion companion flange for cracks, worn

splines, pitted areas, and a rough/corroded seal con-
tact surface. Repair or replace as necessary.

• Pinion depth shims for damage and distortion.

Install new shims if necessary.

• The differential case. Replace the case if cracked

or damaged.

• The axle shaft C-locks for cracks and excessive

wear. Replace them if necessary.

• Each threaded adjuster to determine if it rotates

freely. If an adjuster binds, repair the damaged
threads or replace the adjuster.

• The RWAL exciter ring for damage and missing

teeth. Verify that the ring is fully seated to the dif-
ferential case flange.

Polish each axle shaft sealing surface with No. 600

crocus cloth. This can remove slight surface damage.
Do not reduce the diameter of the axle shaft seal con-
tact surface. When polishing, the crocus cloth should
be moved around the circumference of the shaft (not
in-line with the shaft).

TRAC-LOK

Clean all components in cleaning solvent. Dry com-

ponents with compressed air. Inspect clutch pack
plates for wear, scoring or damage. Replace both
clutch packs if any one component in either pack is
damaged. Inspect side gears and pinions. Replace
any gear that is worn, cracked, chipped or damaged.
Inspect differential case and pinion shaft. Replace if
worn or damaged.

PRESOAK PLATES AND DISC

Plates and discs with fiber coating (no grooves or

lines) must be presoaked in Friction Modifier before
assembly. Soak plates and discs for a minimum of 20
minutes.

Fig. 68 Upper Side Gear & Clutch Disc Pack

Installation

1 – UPPER SIDE GEAR AND CLUTCH DISC PACK
2 – DIFFERENTIAL CASE
3 – SPECIAL TOOL 8139–2

3 - 90

8 1/4 AND 9 1/4 AXLE

DISASSEMBLY AND ASSEMBLY (Continued)

ADJUSTMENTS

8 1/4 AXLE PINION GEAR DEPTH

GENERAL INFORMATION

Ring gear and pinion are supplied as matched sets

only. The identifying numbers for the ring gear and
pinion are painted onto the pinion gear shaft and the
side of the ring gear. A plus (+) number, minus (–)
number or zero (0) along with the gear set sequence
number (01 to 99) is on each gear. This first number
is the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
marked with a (0). The next two numbers are the
sequence number of the gear set. The standard depth
provides the best teeth contact pattern. Refer to
Backlash and Contact Pattern Analysis Paragraph in
this section for additional information.

Compensation

for

pinion

depth

variance

achieved with select shims. The shims are placed
behind the rear pinion bearing (Fig. 69).

If a new gear set is being installed, note the depth

variance marked on both the original and replace-
ment pinion. Add or subtract the thickness of the
original depth shims to compensate for the difference
in the depth variances. Refer to the Depth Variance
chart.

Note where Old and New Pinion Marking columns

intersect.

Intersecting

figure

represents

plus

minus the amount needed.

Note the painted number on the shaft of the pinion

gear (–1, –2, 0, +1, +2, etc.). The numbers represent
thousands of an inch deviation from the standard. If
the number is negative, add that value to the
required thickness of the depth shims. If the number
is positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.

PINION DEPTH MEASUREMENT AND ADJUSTMENT

Measurements are taken with pinion bearing cups

and pinion bearings installed in the axle housing.
Take measurements with Pinion Gauge Set and Dial
Indicator C-3339 (Fig. 70).

(1) Assemble Pinion Height Block 6739, Pinion

Block 8540, and rear pinion bearing onto Screw 6741
(Fig. 70).

(2) Insert assembled height gauge components,

rear bearing, and screw into axle housing through
pinion bearing cups (Fig. 71).

(3) Install front pinion bearing and Cone-Nut 6740

hand tight (Fig. 70).

(4) Place Arbor Disc 8541 on Arbor D-115-3 in posi-

tion in axle housing side bearing cradles (Fig. 72).
Install differential bearing caps on Arbor Discs and
tighten cap bolts to 41 N·m (30 ft. lbs.).

NOTE: Arbor Discs 8541 has different step diame-
ters to fit other axles. Choose proper step for axle
being serviced.

(5) Assemble Dial Indicator C-3339 into Scooter

Block D-115-2 and secure set screw.

(6) Place Scooter Block/Dial Indicator in position

in axle housing so dial probe and scooter block are
flush against the rearward surface of the pinion
height block (Fig. 70). Hold scooter block in place and
zero the dial indicator face to the pointer. Tighten
dial indicator face lock screw.

(7) With scooter block still in position against the

pinion height block, slowly slide the dial indicator
probe over the edge of the pinion height block.

Fig. 69 Shim Locations

1 – AXLE HOUSING
2 – COLLAPSIBLE SPACER
3 – PINION BEARING
4 – PINION DEPTH SHIM
5 – PINION GEAR
6 – BEARING CUP

8 1/4 AND 9 1/4 AXLE

3 - 91

(8) Slide the dial indicator probe across the gap

between the pinion height block and the arbor bar
with the scooter block against the pinion height block
(Fig. 73). When the dial probe contacts the arbor bar,
the dial pointer will turn clockwise. Bring dial
pointer back to zero against the arbor bar, do not
turn dial face. Continue moving the dial probe to the
crest of the arbor bar and record the highest reading.

If the dial indicator can not achieve the zero reading,
the rear bearing cup or the pinion depth gauge set is
not installed correctly.

(9) Select a shim equal to the dial indicator read-

ing plus the drive pinion gear depth variance number
painted in the shaft of the pinion. For example, if the
depth variance is –2, add +0.002 in. to the dial indi-
cator reading.

9 1/4 AXLE PINION GEAR DEPTH

GENERAL INFORMATION

Ring gear and pinion are supplied as matched sets

PINION GEAR DEPTH VARIANCE

Original Pinion

Gear Depth

Variance

Replacement Pinion Gear Depth Variance

−4

−3

−2

−1

+0.008

+0.007

+0.006

+0.005

+0.004

+0.003

+0.002

+0.001

+0.007

+0.006

+0.005

+0.004

+0.003

+0.002

+0.001

−0.001

+0.006

+0.005

+0.004

+0.003

+0.002

+0.001

−0.001

−0.002

+0.005

+0.004

+0.003

+0.002

+0.001

−0.001

−0.002

−0.003

+0.004

+0.003

+0.002

+0.001

−0.001

−0.002

−0.003

−0.004

−1

+0.003

+0.002

+0.001

−0.001

−0.002

−0.003

−0.004

−0.005

−2

+0.002

+0.001

−0.001

−0.002

−0.003

−0.004

−0.005

−0.006

−3

+0.001

−0.001

−0.002

−0.003

−0.004

−0.005

−0.006

−0.007

−4

−0.001

−0.002

−0.003

−0.004

−0.005

−0.006

−0.007

−0.008

Fig. 70 Pinion Gear Depth Gauge Tools

1 – DIAL INDICATOR
2 – ARBOR
3 – PINION HEIGHT BLOCK
4 – CONE
5 – SCREW
6 – PINION BLOCK
7 – SCOOTER BLOCK
8 – ARBOR DISC

Fig. 71 Pinion Height Block

1 – PINION BLOCK
2 – PINION HEIGHT BLOCK

3 - 92

8 1/4 AND 9 1/4 AXLE

ADJUSTMENTS (Continued)

is the amount (in thousandths of an inch) the depth
varies from the standard depth setting of a pinion
marked with a (0). The next two numbers are the
sequence number of the gear set. The standard depth
provides the best teeth contact pattern. Refer to
Backlash and Contact Pattern Analysis Paragraph in
this section for additional information.

Compensation

for

pinion

depth

variance

achieved with select shims. The shims are placed
behind the rear pinion bearing (Fig. 74).

If a new gear set is being installed, note the depth

variance painted onto both the original and replace-
ment pinion. Add or subtract the thickness of the
original depth shims to compensate for the difference
in the depth variances. Refer to the Depth Variance
chart.

Note where Old and New Pinion Marking columns

intersect.

Intersecting

figure

represents

plus

minus the amount needed.

Note the painted number on the shaft of the drive

pinion (–1, –2, 0, +1, +2, etc.). The numbers repre-
sent thousands of an inch deviation from the stan-
dard. If the number is negative, add that value to the
required thickness of the depth shims. If the number
is positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.

Fig. 72 Gauge Tools In Housing

1 – ARBOR DISC
2 – PINION BLOCK
3 – ARBOR
4 – PINION HEIGHT BLOCK

Fig. 73 Pinion Gear Depth Measurement

1 – ARBOR
2 – SCOOTER BLOCK
3 – DIAL INDICATOR

Fig. 74 Shim Locations

1 – AXLE HOUSING
2 – COLLAPSIBLE SPACER
3 – PINION BEARING
4 – PINION DEPTH SHIM
5 – PINION GEAR
6 – BEARING CUP

8 1/4 AND 9 1/4 AXLE

3 - 93

ADJUSTMENTS (Continued)

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