1998 DODGE RAM 1500 gear

FRONT AXLE - C205F
TABLE OF CONTENTS
page page
FRONT AXLE - C205F
DIAGNOSIS AND TESTING................27
REMOVAL.............................31
INSTALLATION.........................31
ADJUSTMENTS........................32
SPECIFICATIONS.......................39
SPECIAL TOOLS.......................40
AXLE SHAFTS
REMOVAL.............................43
INSTALLATION.........................43
AXLE SHAFT SEALS
REMOVAL.............................43
INSTALLATION.........................43
AXLE BEARINGS
REMOVAL.............................43INSTALLATION.........................44
PINION SEAL
REMOVAL.............................44
INSTALLATION.........................45
DIFFERENTIAL
REMOVAL.............................46
DISASSEMBLY.........................47
ASSEMBLY............................47
INSTALLATION.........................48
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................48
INSTALLATION.........................48
PINION GEAR/RING GEAR
REMOVAL.............................49
INSTALLATION.........................51
FRONT AXLE - C205F
DIAGNOSIS AND TESTING
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, tooth contact, worn/damaged
gears or the carrier housing not having the proper
offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate the vehicle to the speed range where the noise is
the greatest. Shift out-of-gear and coast through the
peak-noise range. If the noise stops or changes
greatly check for:
²Insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. The side gears are loaded dur-
ing turns. They usually do not cause noise during
straight-ahead driving when the gears are unloaded.
A worn pinion mate shaft can also cause a snapping
or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearingshave a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Differential bearingsusually produce a low pitch
noise. Differential bearing noise is similar to pinion
bearing noise. The pitch of differential bearing noise
is also constant and varies only with vehicle speed.
Axle shaft bearingsproduce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle.
Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise
level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 m.p.h.
LOW SPEED KNOCK
Low speed knock is generally caused by:
²Worn U-joints/CV joint.
²Worn side-gear thrust washers.
²Worn pinion shaft bore.
DRFRONT AXLE - C205F 3 - 27

VIBRATION
Vibration at the rear of the vehicle is usually
caused by:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out of balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).
²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front end components
or engine/transmission mounts. These components
can contribute to what appears to be a rear end
vibration. Do not overlook engine accessories, brack-
ets and drive belts.
All driveline components should be examined
before starting any repair.
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged) can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints/CV joint.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle on a hoist with the wheels free to rotate. Instruct
the helper to shift the transmission into gear and lis-
ten for the noise. A mechanics stethoscope is helpful
in isolating the source of a noise.
DIAGNOSTIC CHART
Condition Possible Causes Correction
Wheel Noise 1. Wheel loose. 1. Tighten loose nuts.
2. Faulty, brinelled wheel bearing. 2. Replace bearing.
Axle Shaft Noise 1. Misaligned axle tube. 1. Inspect axle tube alignment.
Correct as necessary.
2. Bent or sprung axle shaft. 2. Inspect and correct as necessary.
3. End-play in pinion bearings. 3. Refer to pinion pre-load
information and correct as
necessary.
4. Excessive gear backlash
between the ring gear and pinion.4. Check adjustment of the ring
gear and pinion backlash. Correct
as necessary.
5. Improper adjustment of pinion
gear bearings.5. Adjust the pinion bearings
pre-load.
6. Loose pinion yoke nut. 6. Tighten the pinion yoke nut.
7. Scuffed gear tooth contact
surfaces.7. Inspect and replace as
necessary.
Axle Shaft Broke 1. Misaligned axle tube. 1. Replace the broken shaft after
correcting tube mis-alignment.
2 Vehicle overloaded. 2. Replace broken shaft and avoid
excessive weight on vehicle.
3. Erratic clutch operation. 3. Replace broken shaft and avoid
or correct erratic clutch operation.
4. Grabbing clutch. 4. Replace broken shaft and inspect
and repair clutch as necessary.
3 - 28 FRONT AXLE - C205FDR
FRONT AXLE - C205F (Continued)

Condition Possible Causes Correction
Differential Cracked 1. Improper adjustment of the
differential bearings.1. Replace case and inspect gears
and bearings for further damage.
Set differential bearing pre-load
properly.
2. Excessive ring gear backlash. 2. Replace case and inspect gears
and bearings for further damage.
Set ring gear backlash properly.
3. Vehicle overloaded. 3. Replace case and inspect gears
and bearings for further damage.
Avoid excessive vehicle weight.
4. Erratic clutch operation. 4. Replace case and inspect gears
and bearings for further damage.
Avoid erratic use of clutch.
Differential Gears Scored 1. Insufficient lubrication. 1. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
2. Improper grade of lubricant. 2. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
3. Excessive spinning of one
wheel/tire.3. Replace scored gears. Inspect all
gears, pinion bores, and shaft for
damage. Service as necessary.
Loss Of Lubricant 1. Lubricant level too high. 1. Drain lubricant to the correct
level.
2. Worn axle shaft seals. 2. Replace seals.
3. Cracked differential housing. 3. Repair as necessary.
4. Worn pinion seal. 4. Replace seal.
5. Worn/scored yoke. 5. Replace yoke and seal.
6. Axle cover not properly sealed. 6. Remove, clean, and re-seal
cover.
Axle Overheating 1. Lubricant level low. 1. Fill differential to correct level.
2. Improper grade of lubricant. 2. Fill differential with the correct
fluid type and quantity.
3. Bearing pre-loads too high. 3. Re-adjust bearing pre-loads.
4. Insufficient ring gear backlash. 4. Re-adjust ring gear backlash.
DRFRONT AXLE - C205F 3 - 29
FRONT AXLE - C205F (Continued)

Condition Possible Causes Correction
Gear Teeth Broke 1. Overloading. 1. Replace gears. Examine other
gears and bearings for possible
damage.
2. Erratic clutch operation. 2. Replace gears and examine the
remaining parts for damage. Avoid
erratic clutch operation.
3. Ice-spotted pavement. 3. Replace gears and examine
remaining parts for damage.
4. Improper adjustments. 4. Replace gears and examine
remaining parts for damage. Ensure
ring gear backlash is correct.
Axle Noise 1. Insufficient lubricant. 1. Fill differential with the correct
fluid type and quantity.
2. Improper ring gear and pinion
adjustment.2. Check ring gear and pinion
contact pattern.
3. Unmatched ring gear and pinion. 3. Replace gears with a matched
ring gear and pinion.
4. Worn teeth on ring gear and/or
pinion.4. Replace ring gear and pinion.
5. Loose pinion bearings. 5. Adjust pinion bearing pre-load.
6. Loose differential bearings. 6. Adjust differential bearing
pre-load.
7. Mis-aligned or sprung ring gear. 7. Measure ring gear run-out.
Replace components as necessary.
8. Loose differential bearing cap
bolts.8. Inspect differential components
and replace as necessary. Ensure
that the bearing caps are torqued
tot he proper specification.
9. Housing not machined properly. 9. Replace housing.
3 - 30 FRONT AXLE - C205FDR
FRONT AXLE - C205F (Continued)

ADJUSTMENTS
Ring gear and pinion are supplied as a matched
sets. Identifying numbers for the ring gear and pin-
ion 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.
Compensation for pinion depth variance is
achieved with select shims located between the rear
pinion bearing cone and pinion gear head (Fig. 6).
If installing a new gear, note the depth variance
number of the original and replacement pinion. Add
or subtract this number from the original depth
shim/oil slinger to compensate for the difference in
the depth variances. The numbers represent thou-
sands 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 posi-
tive, subtract that value from the thickness of the
depth shim.
Pinion Gear Depth Variance Chart: Note where
Old and New Pinion Marking columns intersect.
Intersecting figure represents plus or minus the
amount needed.
Fig. 4 DIFFERENTIAL MOUNT
1 - DIFFERENTIAL MOUNT
2 - DIFFERENTIAL HOUSING
3 - MOUNTING BOLTS
Fig. 5 COMPANION FLANGE
1 - COMPANION FLANGE
2 - PROPELLER SHAFT
3 - FLANGE YOKE
4 - REFERENCE MARK
Fig. 6 ADJUSTMENT SHIM
1 - PINION GEAR DEPTH SHIM
2 - DIFFERENTIAL BEARING PRELOAD SHIM
3 - RING GEAR
4 - DIFFERENTIAL BEARING PRELOAD SHIM
5 - COLLAPSIBLE SPACER
3 - 32 FRONT AXLE - C205FDR
FRONT AXLE - C205F (Continued)

PINION GEAR DEPTH VARIANCE
Original Pinion
Gear Depth
VarianceNew Pinion Gear Depth Variance
24232221 0 +1 +2 +3 +4
+4+0.008 +0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0
+3+0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 020.001
+2+0.006 +0.005 +0.004 +0.003 +0.002 +0.001 020.00120.002
+1+0.005 +0.004 +0.003 +0.002 +0.001 020.00120.00220.003
0+0.004 +0.003 +0.002 +0.001 020.00120.00220.00320.004
21+0.003 +0.002 +0.001 020.00120.00220.00320.00420.005
22+0.002 +0.001 020.00120.00220.00320.00420.00520.006
23+0.001 020.00120.00220.00320.00420.00520.00620.007
24020.00120.00220.00320.00420.00520.00620.00720.008
PINION DEPTH MEASUREMENT AND ADJUSTMENT
Measurements are taken with pinion cups and pin-
ion bearings installed in housing. Take measure-
ments with a Pinion Gauge Set, Pinion Block 8177,
Arbor Discs 8541 and Dial Indicator C-3339 (Fig. 7).(1) Assemble Pinion Height Block 6739, Pinion
Block 8177 and rear pinion bearing onto Screw 6741
(Fig. 7).
(2) Insert assembled height gauge components,
rear bearing and screw into the housing through the
pinion bearing cups (Fig. 8).
(3) Install front pinion bearing and Cone-Nut 6740
onto the screw. Tighten cone-nut until Torque To
Rotate the screw is 2.0 N´m (18 in. lbs.) (Fig. 7).
(4) Place Arbor Discs 8541 on Arbor D-115-3 in
position in the housing side bearing cradles (Fig. 9).
Install differential bearing caps on arbor discs and
tighten cap bolts to specification.
(5) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
Fig. 7 PINION GEAR DEPTH GAUGE
1 - DIAL INDICATOR
2 - ARBOR
3 - PINION HEIGHT BLOCK
4 - CONE
5 - SCREW
6 - PINION BLOCK
7 - SCOOTER BLOCK
8 - ARBOR DISC
Fig. 8 PINION HEIGHT BLOCK
1 - PINION BLOCK
2 - PINION HEIGHT BLOCK
DRFRONT AXLE - C205F 3 - 33
FRONT AXLE - C205F (Continued)

(6) Place Scooter Block/Dial Indicator in position
in the housing so dial probe and scooter block are
flush against the surface of the pinion height block.
Hold scooter block in place and zero the dial indica-
tor. Tighten dial indicator face lock screw.
(7) 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. 10). Slide the dial probe to the crest of the arbor
bar and record the highest reading.
(8) Select a shim equal to the dial indicator read-
ing plus the drive pinion gear depth variance number
marked on the shaft of the pinion gear using the
opposite sign on the variance number. For example, if
the depth variance is ±2, add +0.002 in. to the dial
indicator reading.
(9) Remove the pinion depth gauge components
from the housing
DIFFERENTIAL BEARING PRELOAD AND GEAR
BACKLASH
Differential side bearing preload and gear backlash
is achieved by selective shims inserted between the
bearing cup and the housing. The proper shim thick-
ness can be determined using slip-fit Dummy Bear-
ings 8398 in place of the differential side bearings
and a Dial Indicator C-3339. Before measuring differ-
ential bearing preload and gear backlash, measure
pinion gear depth and prepare pinion for installation.Pinion gear depth is essential to establishing gear
backlash and tooth contact patterns. After measuring
shim thickness to take up differential side play,
install pinion and measure gear backlash shim thick-
ness. Overall shim thickness is the dial indicator
reading and preload specification added together. The
gear backlash measurement determines the shim
thickness used on the ring gear side of the differen-
tial case. Subtract gear backlash shim thickness from
overall shim thickness to determine shim thickness
for pinion gear side of the differential (Fig. 11).
Fig. 9 PINION GAUGE TOOLS
1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCK
Fig. 10 PINION GEAR DEPTH MEASUREMENT
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
Fig. 11 ADJUSTMENT SHIM
1 - PINION GEAR DEPTH SHIM
2 - DIFFERENTIAL BEARING PRELOAD SHIM
3 - RING GEAR
4 - DIFFERENTIAL BEARING PRELOAD SHIM
5 - COLLAPSIBLE SPACER
3 - 34 FRONT AXLE - C205FDR
FRONT AXLE - C205F (Continued)

SHIM SELECTION
NOTE: It is difficult to salvage the differential side
bearings during the removal procedure. Install
replacement bearings if necessary.
(1) Remove side bearings from differential case.
(2) Install ring gear if necessary, on differential
case and tighten bolts to specification.
(3) Install Dummy Bearings 8398 on differential
case.
(4) Install differential case in the housing.
(5) Insert Dummy Shims 8107 3.0 mm (0.118 in.)
starting point shims between both dummy bearings
and the housing (Fig. 12).
(6) Install the marked bearing caps in their correct
positions. Install and snug the bolts.
(7) Using a dead-blow hammer to seat the differ-
ential dummy bearings to each side of the differential
housing (Fig. 13) and (Fig. 14).
(8) Install Pilot Stud C-3288-B in cover bolt hole
below ring gear.
Fig. 12 DUMMY SHIM
1 - DUMMY SHIM
2 - DIFFERENTIAL HOUSING
3 - DIFFERENTIAL CASE
4 - DUMMY BEARINGS
Fig. 13 SEAT PINION GEAR SIDE
1 - DEAD-BLOW HAMMER
2 - HOUSING
3 - PINION GEAR SIDE
Fig. 14 SEAT RING GEAR SIDE
1 - HOUSING
2 - DEAD-BLOW HAMMER
3 - RING GEAR SIDE
DRFRONT AXLE - C205F 3 - 35
FRONT AXLE - C205F (Continued)