1998 DODGE RAM 1500 Y case

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)

(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)

(9) Attach Dial Indicator C-3339 to post and posi-
tion dial indicator plunger on a flat surface on a ring
gear bolt head (Fig. 15).
(10) Push and hold differential to the pinion gear
side of the housing (Fig. 16) and zero dial indicator.
(11) Push and hold differential case to the ring
gear side and record dial indicator reading (Fig. 17).
(12) Add the dial indicator reading to the starting
point shim thicknesses to determine the total shim
thickness necessary to achieve zero differential end
play.
(13) Add 0.2 mm (0.008 in) to the zero end play
total. This new total represents the shims needed to
preload the new differential case bearings.
(14) Rotate dial indicator out of the way on pilot
stud.
(15) Remove differential case, dummy bearings
and dummy shims from the housing.
(16) Install the pinion gear in the housing. Install
the companion flange and establish the correct pinion
rotating torque.
(17) Install differential case and Dummy Bearings
in the housing with a single dummy shim on the ring
gear side of the axle and tighten retaining cap bolts.
(18) Position the dial indicator plunger on a flat
surface between the ring gear bolt heads (Fig. 15).
(19) Push and hold differential case toward pinion.
(20) Zero dial indicator face to pointer.(21) Push and hold differential case to ring gear
side of the housing.
(22) Record dial indicator reading.
Fig. 15 DIFFERENTIAL SIDE PLAY
1 - DIFFERENTIAL
2 - PILOT STUD
3 - DIAL INDICATOR
Fig. 16 ZERO DIAL INDICATOR
1 - PINION GEAR SIDE
2 - PILOT STUD
3 - DIAL INDICATOR
Fig. 17 RECORD DIAL INDICATOR
1 - DIAL INDICATOR
2 - HOUSING
3 - RING GEAR SIDE
3 - 36 FRONT AXLE - C205FDR
FRONT AXLE - C205F (Continued)

(23) Subtract 0.05 mm (0.002 in.) from the dial
indicator reading to compensate for backlash between
ring and pinion gears. Add the resulting measure-
ment to the thickness of the single dummy shim.
This is the thickness of shim required to achieve
proper backlash.
(24) Subtract the backlash shim thickness from
the total preload shim thickness. The remainder is
the shim thickness required on the pinion side of the
housing.
(25) Rotate dial indicator out of the way on pilot
stud.
(26) Remove differential case, dummy bearings
and dummy shim from the housing.
(27) Install new side bearing cones and cups on
differential case.
(28) Install Spreader W-129-B and Adapter Plates
8142-A on the housing and spread open enough to
receive differential case.
CAUTION: Never spread over 0.50 mm (0.020 in). If
the housing is over-spread, it could be distorted or
damaged.
(29) Place the side bearing shims in the differen-
tial housing against the housing shoulder.
(30) Install the differential case in the housing.
(31) Rotate the differential case several times to
seat the side bearings.
(32) Position the dial indicator plunger against a
ring gear tooth (Fig. 18).
(33) Push and hold ring gear upward while not
allowing the pinion gear to rotate.
(34) Zero dial indicator face to pointer.
(35) Push and hold ring gear downward while not
allowing the pinion gear to rotate. Dial indicator
reading should be between 0.12 mm (0.005 in.) and0.20 mm (0.008 in.). If backlash is not within specifi-
cations transfer the necessary amount of shim thick-
ness from one side of the differential housing to the
other (Fig. 19).
(36) Verify differential case and ring gear runout
by measuring ring to pinion gear backlash at eight
locations around the ring gear. Readings should not
vary more than 0.05 mm (0.002 in.). If readings vary
more than specified, the ring gear or the differential
case is defective.
After the proper backlash is achieved, perform the
Gear Contact Pattern procedure.
GEAR CONTACT PATTERN
Gear tooth contact pattern is used to verify the cor-
rect running position of the ring and pinion gears.
This will produce low noise and long gear life. Gears
which are not positioned properly may be noisy and
have shorten gear life.
(1) Wipe clean each tooth of the ring gear.
(2) Apply gear marking compound to all of the ring
gear teeth.
(3) Verify bearing cap bolts are torque specifica-
tion.
(4) Apply the brakes lightly to create at 14 N´m
(10 ft. lbs.) pinion rotating torque.
(5) Rotate the pinion/pinion yoke 4 full revolutions
in each directions.
(6) Read gear tooth contact pattern:
²Gear contact pattern correct (Fig. 20). Backlash
and pinion depth is correct.
Fig. 18 RING GEAR BACKLASH
1 - RING GEAR
2 - DIAL INDICATOR
Fig. 19 BACKLASH SHIM ADJUSTMENT
DRFRONT AXLE - C205F 3 - 37
FRONT AXLE - C205F (Continued)

²Pinion gear set too high (Fig. 26). Decrease pin-
ion depth, by decreasing the pinion depth shim thick-
ness.
SPECIFICATIONS
AXLE SPECIFICATIONS
DESCRIPTION SPECIFICATION
Axle Ratio 3.55, 3.92
Differential Case Flange Runout 0.076 mm (0.003 in.)
Differential Side Gear Clearance 0-0.15 mm (0-0.006 in.)
Ring Gear Diameter 205 mm (8.0 in.)
Ring Gear Backlash 0.12-0.20 mm (0.005-0.008 in.)
Ring Gear Runout 0.12 mm (0.005 in.)
Pinion Bearing Preload - New Bearings 2.0-2.8 N´m (18-25 in. lbs.)
Pinion Bearing Preload - Original Bearings 1-2 N´m (10-20 in. lbs.)
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Mounting Nuts 95 70 -
Differential Fill Hole Plug 34 25 -
Differential Cover Bolts 22 15 -
Bearing Cap Bolts 61 45 -
Ring Gear Bolts 108 80 -
Pinion Nut 271-475 200-350 -
Fig. 26 HIGH PINION HEIGHT
DRFRONT AXLE - C205F 3 - 39
FRONT AXLE - C205F (Continued)