oil MERCEDES-BENZ SPRINTER 2006 Service Manual

(6) Separate piston guide ring (13) and the B2 pis-
ton (10) from the B3 piston (8) by blowing com-
pressed air into the bore (D) (Fig. 176).
(7) Press piston guide ring (13) out of the B2 pis-
ton (10).
(8) Separate piston guide (4) from the B3 piston
(8) by blowing compressed air into the bore (A) (Fig.
176).
Fig. 176 B2 Clutch Oil Supply Locations
A - B3 PISTON
B - B2 PISTON GUIDE RING SIDE
C - K3 CLUTCH FEED
D - B2 PISTON SHIFT SIDE
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 149

OPERATION
Signals from the input speed sensors (6, 8) (Fig.
183) are recorded in the transmission control module
(TCM) together with the wheel and engine speeds
and other information and are processed into an
input signal for electronic control.
Input speed sensor N2 (6) records the speed of the
front sun gear via the externally toothed disc carrier
of the multiple-disc clutch K1 (10) and input speed
sensor N3 (8) records the speed of the front planet
carrier via the internally toothed disc carrier of mul-
tiple-disc clutch K1 (3).
OIL PUMP
DESCRIPTION
The oil pump (2) (Fig. 184) (crescent-type pump) is
installed in the bellhousing behind the torque con-
verter and is driven by the drive flange of the torque
converter. The pump creates the oil pressure required
for the hydraulic procedures.
OPERATION
When the engine is running, the oil (Fig. 185) is
pumped through the inlet chamber (5) along the
Fig. 183 Input Speed Sensors
1 - DRIVING CLUTCH K1
2 - TRANSMISSION HOUSING
3 - DRIVING CLUTCH K1 INTERNALLY TOOTHED DISC
4 - EXCITER RING
5 - VALVE HOUSING OF SHIFT PLATE
6 - N2 INPUT SPEED SENSOR
7 - SPRING
8 - N3 INPUT SPEED SENSOR
9 - EXCITER RING
10 - DRIVING CLUTCH K1 EXTERNALLY TOOTHED DISC
Fig. 184 Oil Pump
1 - CRESCENT
2 - OIL PUMP
3 - EXTERNAL GEAR
4 - INTERNAL GEAR
5 - INLET CHAMBER
6 - PRESSURE CHAMBER
Fig. 185 Oil Pump
1 - CRESCENT
2 - OIL PUMP
3 - EXTERNAL GEAR
4 - INTERNAL GEAR
5 - INLET CHAMBER
6 - PRESSURE CHAMBER
21 - 154 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

upper and lower side of the crescent (1) to the pres-
sure chamber (6) of the housing. The meshing of the
teeth prevents oil flowing from the delivery side to
the intake side. An external gear (3) is eccentrically
mounted in the pump housing. The external gear is
driven by the internal gear (4) which is connected to
the torque converter hub.
DISASSEMBLY
(1) Remove pump gears (1 and 2) (Fig. 186) from
pump housing.
(2) Remove the inner oil pump seal (1) (Fig. 187).
(3) Replace the outer oil pump O-ring (2) (Fig.
187).
INSPECTION
Before measuring any oil pump components, per-
form a thorough visual inspection of all the compo-nents. If any sign of scoring, scratches, or other
damage is seen, replace the oil pump as an assembly.
SIDE CLEARANCE
Side clearance is the difference between the thick-
ness of the pump gears and the depth of the pocket
in the pump housing. Side clearance can be mea-
sured by laying a flat plate across the mounting face
of the pump housing, and measuring the distance
between the plate and the gears.
Acceptable side clearance:
²Inner gear: 0.064 mm (0.0025 in) max
²Outer gear: 0.069 mm (0.0027 in) max
TIP CLEARANCE
Tip clearance is the difference between the tip
diameters of the gear teeth and the corresponding
diameters of the pocket in the pump housing.
Tip clearance for the inner gear can be checked by
moving the inner gear into tight mesh (2) (Fig. 188)
with the outer gear as shown. Clearance between the
ID of the crescent feature of the housing and the OD
of the teeth of the inner gear (3) should then me
measured at a point 37 mm from the corner of the
crescent (1) feature, as shown below.
Acceptable tip clearance for inner gear:
²0.85 mm (0.033 in) max
Fig. 186 Oil Pump Gears
1 - OUTER PUMP ROTOR
2 - INNER PUMP ROTOR
Fig. 187 Remove Oil Pump Seals
1 - INNER OIL SEAL
2 - OUTER OIL SEAL
Fig. 188 Oil Pump Measurement
1 - MEASURE 37MM FROM THE CORNER OF CRESCENT
2 - TIGHT MESH HERE
3 - MEASURE TIP CLEARANCE HERE
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 155

ASSEMBLY
(1) Install new inner oil pump seal (1) (Fig. 189)
with Seal Installer 8902-A.
(2) Replace O-ring (2) (Fig. 189).
(3) Lubricate pump gears and place in the pump
housing. Insert pump gear (1) (Fig. 190) so that the
chamfer (arrow) points towards the pump housing.
OUTPUT SHAFT BEARING
REMOVAL
(1) Raise and support vehicle.
(2) Remove the propeller shaft (Refer to 3 - DIF-
FERENTIAL & DRIVELINE/PROPELLER SHAFT/
PROPELLER SHAFT - REMOVAL).
(3) Verify that the transmission is in PARK in
order to prepare for the removal of the output shaft
nut.
(4) Remove the nut holding the propeller shaft
flange to the output shaft and remove the flange.
(5) Remove the transmission rear oil seal with a
suitable slide hammer and screw.
(6) Remove the transmission output shaft washer.
Be sure to tag the washer since it is very similar to
the geartrain end-play shim and they must not be
interchanged.
(7) Remove the transmission rear output shaft
bearing retaining ring (1) (Fig. 191).
Fig. 189 Install New Oil Pump Seals
1 - INNER OIL SEAL
2 - OUTER OIL SEAL
Fig. 190 Oil Pump Gears
1 - OUTER PUMP ROTOR
2 - INNER PUMP ROTOR
Fig. 191 Remove Rear Output Shaft Retaining Ring
1 - RETAINING RING
2 - OUTPUT SHAFT BEARING
21 - 156 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

(5) Turn on ignition and apply brakes. Move selec-
tor lever back to position ªDº.
(6) Install the transmission shift cable onto the
ball knob at the SLA.
(7) Install the bottom (2) (Fig. 227) of the center
section of instrument panel.
(8) Install the top (3) (Fig. 228) of the center sec-
tion of instrument panel.
(9) Verify repair.
SOLENOID
DESCRIPTION
The typical electrical solenoid used in automotive
applications is a linear actuator. It is a device that
produces motion in a straight line. This straight line
motion can be either forward or backward in direc-
tion, and short or long distance.
A solenoid is an electromechanical device that uses
a magnetic force to perform work. It consists of a coil
of wire, wrapped around a magnetic core made from
steel or iron, and a spring loaded, movable plunger,
which performs the work, or straight line motion.
The solenoids used in transmission applications
are attached to valves which can be classified asnor-
mally openornormally closed. Thenormally
opensolenoid valve is defined as a valve which
allows hydraulic flow when no current or voltage is
applied to the solenoid. Thenormally closedsole-
noid valve is defined as a valve which does not allow
hydraulic flow when no current or voltage is applied
to the solenoid. These valves perform hydraulic con-
trol functions for the transmission and must there-
fore be durable and tolerant of dirt particles. For
these reasons, the valves have hardened steel pop-
pets and ball valves. The solenoids operate the valves
Fig. 227 Install Bottom Section Of Center
Instrument Panel
1 - SCREW
2 - BOTTOM CENTER PART OF INSTRUMENT PANEL
Fig. 228 Install Top Section Of Center Instrument
Panel
1 - SHIFT LEVER ASSEMBLY FRAME TRIM
2 - STORAGE COMPARTMENT
3 - TOP CENTER PART OF INSTRUMENT PANEL
4 - SCREW
5 - PLUG CONNECTIONS
6 - ASHTRAY
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 171

directly, which means that the solenoids must have
very high outputs to close the valves against the siz-
able flow areas and line pressures found in current
transmissions. Fast response time is also necessary
to ensure accurate control of the transmission.
The strength of the magnetic field is the primary
force that determines the speed of operation in a par-
ticular solenoid design. A stronger magnetic field will
cause the plunger to move at a greater speed than a
weaker one. There are basically two ways to increase
the force of the magnetic field:
1. Increase the amount of current applied to the
coil or
2. Increase the number of turns of wire in the coil.
The most common practice is to increase the num-
ber of turns by using thin wire that can completely
fill the available space within the solenoid housing.
The strength of the spring and the length of the
plunger also contribute to the response speed possi-
ble by a particular solenoid design.
A solenoid can also be described by the method by
which it is controlled. Some of the possibilities
include variable force, pulse-width modulated, con-
stant ON, or duty cycle. The variable force and pulse-
width modulated versions utilize similar methods to
control the current flow through the solenoid to posi-
tion the solenoid plunger at a desired position some-
where between full ON and full OFF. The constant
ON and duty cycled versions control the voltage
across the solenoid to allow either full flow or no flow
through the solenoid's valve.UPSHIFT / DOWNSHIFT SOLENOID VALVES
The solenoid valves (1) for upshifts and downshifts
(Fig. 229) are located in the shell of the electric con-
trol unit and pressed against the shift plate with a
spring.
The solenoid valves (1) initiate the upshift and
downshift procedures in the shift plate.
The solenoid valves (1) are sealed off from the
valve housing of the shift plate (5) by two O-rings (4,
6). The contact springs (8) at the solenoid valve
engage in a slot in the conductor tracks (7). The force
of the contact spring (8) ensures safe contacts.
Fig. 229 Upshift/Downshift Solenoid Valves
1 - UPSHIFT/DOWNSHIFT SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - O-RING
5 - VALVE HOUSING OF SHIFT PLATE
6 - O-RING
7 - CONDUCTOR TRACK
8 - CONTACT SPRING
21 - 172 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

SHIFT PRESSURE CONTROL SOLENOID VALVE
The shift pressure control solenoid valve (1) (Fig.
232) is located in the shell of the electric valve con-
trol unit and pressed against the shift plate by a
spring.
Its purpose is to control the shift pressure depend-
ing on the continuously changing operating condi-
tions, such as load and gear change.
The shift pressure regulating solenoid valve (1) has
an interference fit and is sealed off to the valve body
of the shift plate (4) by a seal (arrow). The contact
springs (2) at the solenoid valve engage in a slot in
the conductor tracks (3). The force of the contact
springs (2) ensures secure contacts.
OPERATION
When an electrical current is applied to the sole-
noid coil, a magnetic field is created which produces
an attraction to the plunger, causing the plunger to
move and work against the spring pressure and the
load applied by the fluid the valve is controlling. The
plunger is normally directly attached to the valve
which it is to operate. When the current is removed
from the coil, the attraction is removed and the
plunger will return to its original position due to
spring pressure.
The plunger is made of a conductive material and
accomplishes this movement by providing a path forthe magnetic field to flow. By keeping the air gap
between the plunger and the coil to the minimum
necessary to allow free movement of the plunger, the
magnetic field is maximized.
UPSHIFT / DOWNSHIFT SOLENOID VALVES
If a solenoid valve (1) (Fig. 233) is actuated by the
TCM, it opens and guides the control pressure (p-SV)
to the assigned command valve. The solenoid valve
remains actuated and therefore open until the shift-
ing process is complete. The shift pressure (p-SV) to
the command valve is reduced to zero as soon as the
power supply to the solenoid valve is interrupted.
Fig. 232 Shift Pressure Control Solenoid Valve
1 - SHIFT PRESSURE CONTROL SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - VALVE HOUSING SHIFT PLATE
5 - CONDUCTOR TRACK
6 - CONTACT SPRING
Fig. 233 Upshift/Downshift Solenoid Valves
1 - UPSHIFT/DOWNSHIFT SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - O-RING
5 - VALVE HOUSING OF SHIFT PLATE
6 - O-RING
7 - CONDUCTOR TRACK
8 - CONTACT SPRING
21 - 174 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

The transmission oil temperature sensor (1) (Fig.
238) is located in the shell of the electric valve con-
trol unit and is fixed to the conductor tracks.
Its purpose is to measure the temperature of the
transmission oil and pass the temperature to the
TCM as an input signal. It is a temperature-depen-
dent resistor (PTC).
OPERATION
PARK / NEUTRAL CONTACT
In selector lever positions ªPº and ªNº the park/
neutral contact (4) (Fig. 239) is actuated by a cam
track which is located on the detent plate. The per-
manent magnet (3) is moved away from the dry-reed
contact (4). The dry-reed contact (4) is opened. The
TCM receives an electric signal. The circuit to the
starter in the selector lever positions9Pº and ªNº is
closed.
TRANSMISSION TEMPERATURE SENSOR
The temperature of the transmission oil has a con-
siderable effect on the shifting time and therefore the
shift quality. By measuring the oil temperature, shift
operations can be optimized in all temperature
ranges. The transmission oil temperature sensor (1)
(Fig. 240) is switched in series with the park/neutral
contact. The temperature signal is transferred to the
TCM only when the dry-reed contact of the park/neu-
tral contact is closed in REVERSE or a forward gear
position.
Fig. 239 Park/Neutral Contact
1 - SHELL OF ELECTRIC CONTROL MODULE
2 - PLUNGER
3 - PERMANENT MAGNET
4 - DRY-REED CONTACT
Fig. 240 Transmission Temperature Sensor
1 - TRANSMISSION TEMPERATURE SENSOR
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 177

Refer to the Transmission Temperature Sensor
Specifications table (Fig. 241) for the relationship
between transmission temperature, sensor voltage,
and sensor resistance.
TORQUE CONVERTER
DESCRIPTION
CAUTION: The torque converter must be replaced if
a transmission failure resulted in large amounts of
metal or fiber contamination in the fluid.
The torque converter (Fig. 242) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine (1), a stator (3),
an overrunning clutch, an impeller (2), and an elec-
tronically applied converter clutch. The converter
clutch provides reduced engine speed and greater
fuel economy when engaged. Clutch engagement also
provides reduced transmission fluid temperatures.
The converter clutch engages in third through fifth
gears. The torque converter hub drives the transmis-
sion oil (fluid) pump.
A turbine damper (6) has been added for some
applications to help improve vehicle noise, vibration,
and harshness (NVH) characteristics.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
Fig. 241 Transmission Temperature Sensor
Specifications
Fig. 242 Torque Converter
1 - TURBINE
2 - IMPELLER
3-STATOR
4 - INPUT SHAFT
5 - STATOR SHAFT
6 - TURBINE DAMPER
21 - 178 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

IMPELLER
The impeller (3) (Fig. 243) is an integral part of
the converter housing. The impeller consists of
curved blades placed radially along the inside of the
housing on the transmission side of the converter. As
the converter housing is rotated by the engine, so is
the impeller, because they are one and the same and
are the driving members of the system.
Fig. 243 Impeller
1 - ENGINE FLEXPLATE 4 - ENGINE ROTATION
2 - OIL FLOW FROM IMPELLER SECTION INTO TURBINE SEC-
TION5 - ENGINE ROTATION
3 - IMPELLER VANES AND COVER ARE INTEGRAL
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 179