Differential Cleaning And Inspection; Differential Assembly - Jeep 1979 CJ-5 Technical & Service Manual

CAUTION: Keep the bearing cup tool seated squarely
on the cup to prevent damaging the cup bores during
removal
Cleaning and inspection
Clean all parts in solvent. Allow bearings to air dry.
Dry other parts with compressed air.
Inspect the differential bearing cones, cups, and roll-
ers for pitting, galling, flat spots, or cracks.
Inspect the differential case for an elongated or en-
larged pinion mate shaft hole. The machined thrust
washer surface areas and counterbores must be smooth
and free of nicks, gouges, cracks, or burrs. Inspect the
differential case for cracks or other visible damage
which would necessitate replacement.
Inspect the pinion mate shaft for excessive wear in the
contact area of the differential pinions. The shaft should
be smooth and concentric and not scored or galled.
Inspect the differential side gears and pinions; they
should have smooth teeth with a uniform contact pat-
tern but not display excessive wear or broken surfaces.
The side gear and pinion thrust washers should be
smooth and free from any scoring or metal pickup.
Inspect the pinion mate shaft lockpin for damage or
looseness in the case. Replace the pin or case as
necessary.
Inspect the ring and pinion gears for worn or chipped
teeth or damaged attaching bolt threads. If replacement
is necessary, replace the ring gear and pinion as a
matched set only.
Inspect the pinion bearing cones, cups, and rollers for
pitting, galling, excessive wear, or other visible damage.
Replace any part that exhibits any of these conditions.
Inspect the axle housing for cracks, porosity, bent or
loose tubes, or other damage. In addition, if raised metal
was created on the pinion bearing cup bore shoulders
during cup removal, flatten it using a blunt punch.
Inspect the pinion gear for damaged bearing journals,
damaged shim surfaces, or excessively worn splines. If
pinion replacement is necessary, replace both the pinion
gear and ring gear as a matched set only.
Inspect the pinion yoke for cracks, worn splines, and a
pitted, rough, or corroded oil seal contact surface. Re-
pair or replace the yoke as necessary.
Inspect the pinion gear depth adjustment shims for
being broken, damaged, or distorted. Replace the shims
as necessary before adjusting pinion gear depth.
Differential Assembly
Pinion Qear Depth measurement and Ad|ustment
Pinion gear depth is the distance (measured in inches)
from the end (button) face of the pinion gear to the
centerline of the axle shafts (fig. 2F-35). This dimension
is controlled by shims installed between the pinion gear
rear bearing cup and axle housing (fig. 2F-35).
Ring and pinion sets are factory tested to detect ma-
chining variances. Tests are started at a standard set-
ting which is then varied to obtain the most desirable
tooth contact pattern and quiet operation. When this
setting is determined, the ring and pinion gear are et-
ched with identifying numbers (fig. 2F-36).
The ring gear receives one number. The pinion gear
receives two numbers which are separated by a plus (+)
or minus (-) sign.
The second number on the pinion gear indicates pinion
position, in relation to the centerline of the axle shafts,
where tooth contact was best and gear operation was
quietest. This number represents pinion depth variance
and indicates the amount, in thousandths of an inch,
that the gear set varied from the standard setting. The
number on the ring gear and first number on the pinion
gear identify the gears as a matched set. Do not attempt
to use a ring and pinion set having differing numbers.
This is not a matched set.
The standard setting for AMC/Jeep axles is 2.547
inches (6.46 cm). If the pinion is marked +2, the gear set
varied from standard by +0.002 inches (0.05 mm) and
will require 0.002 inch (0.05 mm) less shims than a gear
set marked zero (0). When a gear set is marked plus (+),
the distance from the pinion end face to the axle shaft
centerline must be more than the standard setting. If
the pinion gear is marked -3, the gear set varied from
standard by 0.003 inches (0.07 mm) and will require
0.003 (0.07 mm) more shims than a set marked zero (0).
When a set is marked minus (-), the distance from the
pinion end face to the axle shaft centerline must be less
than the standard setting. Refer to Figure 2F-35 for an
illustration of the standard setting dimension.
N O T E : On some factory installed gear sets, an addi-
tional 0.010 or 0.020 inches (0.25 or 0.50 mm) may have
been machined off the pinion gear buttonface. This does
not affect gear operation but does affect pinion gear
marking and depth measurement. Pinion gears ma-
chined in this fashion have different identifying num-
bers. For example, if the pinion is marked +23, the
number 2 indicates that 0.020 (0.50 mm) was removed
from the pinion button face and the number 3 indicates
that variance from the standard setting is +0.003 (0.07
mm). If the pinion is marked +16, the number 1 in-
dicates that 0.010 (0.25 mm) was removed from the
pinion buttonface and the number 6 indicates that vari-
ance from the standard setting is +0.006 (0.15 mm).
Gear sets with additional amounts machined off the
pinion button face are factory installed items exclu-
sively. All service replacement gear sets will be ma-
chined to standard settings only. In addition,
replacement gear sets marked + or -0.009 (0.22 mm) or
more, or sets with mismatched identifying numbers
must be returned to the parts distribution center. Do not
attempt to install these gear sets.