Rear Axle; Gear Noise; Bearing Noise - Mercedes-Benz 2005 Sprinter Service Manual

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REAR AXLE

REAR AXLE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 10
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
DIAGNOSIS AND TESTING . . . . . . . . . . . . . . . . 10
STANDARD PROCEDURE - DRAIN AND FILL
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 12
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . 13
SPECIAL TOOLS . . . . . . . . . . . . . . . . . . . . . . . 14
AXLE SHAFTS
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 15
REAR AXLE
DESCRIPTION
The axle housings consist of a cast iron center sec-
tion with axle tubes extending from either side. The
tubes are pressed into and welded to the differential
housing to form a one-piece axle housing. The SRW
axle has semi-floating axle shafts, DRW has full-
floating axle shafts.
NOTE: Axle seals, axle bearings, pinion seal and
differential cover are the only serviceble compo-
nents. If differential is damaged/noisy the axle must
be replaced.
OPERATION
The axle receives power from the transmission
through the rear propeller shaft. The 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.
DIAGNOSIS AND TESTING
NOTE: Axle seals, axle bearings, pinion seals and
differential cover are the only serviceble compo-
nents. If differential is damaged/noisy the axle must
be replaced.
REAR AXLE
TABLE OF CONTENTS
page
AXLE BEARINGS/SEALS
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
INSTALLATION
AXLE SHAFTS - DUAL REAR WHEELS
. . 11 REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
INSTALLATION
AXLE HUB BEARINGS/SEALS
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
INSTALLATION
PINION SEAL
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
INSTALLATION

GEAR NOISE

Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, 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 insufficient lubricant.
• Incorrect ring gear backlash.
• Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping 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 bearings have 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
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