engine MERCEDES-BENZ SPRINTER 2005 Service Repair Manual

(a) Remove bracket for the oil cooler feed and
return lines (1) (Fig. 23) from engine oil pan
flange. Detail shows right side of motor. Position is
mirrored for the left side of engine.
(b) Detach bracket of cable retainer (4) (Fig. 24)
from the threaded shank of a engine oil pan bolt
(5).
(c) Press cable retainer (4) (Fig. 24) down and
out.
(d) Remove the bolts holding the oil cooler lines
(6) (Fig. 25) to the left and right sides of transmis-
sion and hang the lines to the side.
(10) Disconnect the transmission electrical connec-
tor (2) (Fig. 26) from transmission and hang to the
side. Turn sealing ring (3) counterclockwise and dis-
connect plug connection (2).
(11) Detach shift cable at transmission.(a) Unlatch ball socket latch (Fig. 27) of cable.
(b) Unclip shift cable retainer from retainer
bracket. When pulling out cable, press together
hooks of shift cable retainer at the points shown
(arrows).
(c) Pull shift cable out of ball socket. Ball socket
can remain on transmission lever.
(12) Remove the torque converter bolts.
(a) Remove the steering gear (1) (Fig. 28) from
the chassis crossmember.
(b) Lower the steering gear (1) (Fig. 28) down-
wards.
(c) Remove the plastic torque converter access
cover (1) (Fig. 29) at back of engine flange.
Fig. 23 Remove Cooler Line Supports
1 - COOLER LINES
Fig. 24 Remove Cable Support
1 - CABLE
2 - BOLT
Fig. 25 Remove Driver's Side Cooler Line
1 - COOLER LINE
Fig. 26 Remove Transmission Electrical Connector
and Cooler Line
1 - COOLER LINE
2 - TRANSMISSION ELECTRICAL CONNECTOR
3 - SEALING RING
21 - 28 AUTOMATIC TRANSMISSION - NAG1VA
AUTOMATIC TRANSMISSION - NAG1 (Continued)

(d) Rotate engine by hand until bolts (2) (Fig.
29) are in front of opening. Rotate engine forwards
at crankshaft.
(e) To remove bolts, position a ratchet with long
extension and joint nut as shown (Fig. 30).
(f) Remove3x2bolts (2) (Fig. 29) at circumfer-
ence of driving plate.
(13) Support engine. Insert wooden block between
oil pan and front chassis crossmember beam.
(14) Remove vent hose bracket and tie back to one
side.
(15) Disconnect ground strap and tie back to one
side.(16) Remove bolts (A) (Fig. 31) on underside of
transmission. Two bolts (A) on top of transmission
must remain in the housing.
(17) Place hydraulic transmission jack under
transmission and raise slightly. Secure transmission
on hydraulic jack with a strap or ask an assistant to
hold it.
Fig. 27 Remove Shift Cable From Transmission
1 - SHIFT CABLE
2 - TRANSMISSION SHIFT LEVER
Fig. 28 Lower Steering Gear
1 - STEERING GEAR
2 - BRACKET
Fig. 29 Remove Torque Converter Access Cover
1 - TORQUE CONVERTER ACCESS COVER
2 - BOLT
Fig. 30 Remove Torque Converter Bolts
1 - BOLT
2 - STABILIZER BAR
3 - REINFORCEMENT PLATE
4 - OPENING
5 - CHASSIS CROSSMEMBER
6 - STEERING GEAR
VAAUTOMATIC TRANSMISSION - NAG1 21 - 29
AUTOMATIC TRANSMISSION - NAG1 (Continued)

(18) Remove rear engine cross member (4) (Fig.
31). First remove the nuts (5) at the outside ends of
the engine crossmember. Then remove the bolts (1) of
the transmission mount.
(19) Remove the last bolts (A, B) (Fig. 31) on the
top of the transmission.
(20) Remove the transmission towards the rear
and lower. Ensure that the converter remains in the
transmission housing when the transmission is
removed.
(21) Remove the torque converter.
DISASSEMBLY
(1) Remove the torque converter (1) (Fig. 32).
(2) Place transmission in a vertical position.
(3) Measure input shaft end play as follows (Fig.
33).
(a) Attach Adapter 8266-18 to Handle 8266-8.
(b) Attach dial indicator C-3339 to Handle
8266-8.
(c) Install the assembled tool onto the input
shaft of the transmission and tighten the retaining
screw on Adapter 8266-18 to secure it to the input
shaft.
(d) Position the dial indicator plunger against a
flat spot on the oil pump and zero the dial indica-
tor.(e) Move the input shaft in and out. Record the
maximum travel for assembly reference.
(4) Loosen guide bushing (12) (Fig. 34) and remove
from transmission housing.
Fig. 31 Support Transmission and Remove Bolts
1 - BOLT, TRANSMISSION MOUNT
2 - UPPER SHELL FOR TRANSMISSION MOUNT
3 - TRANSMISSION MOUNT
4 - CROSSMEMBER
5 - NUT, ENGINE CROSSMEMBER
6 - NUT, TRANSMISSION SUPPORT
Fig. 32 Remove Torque Converter
1 - TORQUE CONVERTER
2 - CONVERTER HOUSING
Fig. 33 Checking Input Shaft End Play
1 - TOOL 8266-8
2 - TOOL 8266-18
3 - TOOL C-3339
21 - 30 AUTOMATIC TRANSMISSION - NAG1VA
AUTOMATIC TRANSMISSION - NAG1 (Continued)

(3) Move the torque converter (1) (Fig. 59) to
shown position. Check position of torque converter
through housing opening (2) when installing trans-
mission.
(4) Move driving plate (1) (Fig. 60) to shown posi-
tion.
(5) Ensure the dowel pins are installed in their
correct position at the transmission housing flange.
(6) Place transmission onto a hydraulic transmis-
sion jack and raise the transmission into position.
Secure transmission on hydraulic jack with a strap
or ask an assistant to hold it.(7) Move the transmission into position on the
dowel pins and install two bolts (A, B) (Fig. 61) on
the top of the transmission. Torque the bolts to 38
N´m (28 ft.lbs.).
(8) Install the bolt to hose the vent hose bracket to
the transmission. Torque the bolt to 38 N´m (28
ft.lbs.).
(9) Install the bolt to hold the ground strap to the
transmission. Torque the bolt to 38 N´m (28 ft.lbs.).
(10) Install bolts (A) (Fig. 61) on underside of
transmission. Torque the bolts to 38 N´m (28 ft.lbs.).
(11) Install rear engine cross member (4) (Fig. 61).
First install the nuts (5) at the outside ends of the
engine crossmember. Then install the bolts (1) of the
transmission mount. Torque the bolts and nuts to 45
N´m (33 ft.lbs.).
(12) Remove the wooden block supporting the
engine and remove the hydraulic jack.
(13) Install the torque converter bolts.
(a) Install the first pair bolts (2) (Fig. 62) at cir-
cumference of driving plate snug only.
Fig. 59 Position Torque Converter as Shown
1 - TORQUE CONVERTER
2 - INSPECTION OPENING
Fig. 60 Position Driveplate as Shown
1 - DRIVEPLATE
Fig. 61 Support Transmission and Install Bolts
1 - BOLT, TRANSMISSION MOUNT
2 - UPPER SHELL FOR TRANSMISSION MOUNT
3 - TRANSMISSION MOUNT
4 - CROSSMEMBER
5 - NUT, ENGINE CROSSMEMBER
6 - NUT, TRANSMISSION SUPPORT
21 - 42 AUTOMATIC TRANSMISSION - NAG1VA
AUTOMATIC TRANSMISSION - NAG1 (Continued)

(b) To install bolts, position a ratchet with long
extension and joint nut as shown.
(c) Rotate engine by hand until the next pair of
bolts (2) are in front of opening. Rotate engine for-
wards at crankshaft. Install the next pair of bolts
snug only.
(d) Rotate engine by hand until the final pair of
bolts (2) are in front of opening. Rotate engine for-
wards at crankshaft. Install and torque the bolts to
50 N´m (37 ft.lbs.).
(e) Rotate engine by hand and tighten the first
two bolt pairs to 50 N´m (37 ft.lbs.).
(f) Install the plastic torque converter access
cover (1) (Fig. 63) to the back of the engine flange.
(g) Install the steering gear (1) (Fig. 64) onto the
chassis crossmember. Tighten both steering gear
bolts first to 25 N´m (18.5 ft.lbs.). Tighten both
steering gear bolts next to 45 N´m (33 ft.lbs.).
Tighten both steering gear bolts next an additional
90É.
Fig. 62 Install Torque Converter Bolts
1 - BOLT
2 - STABILIZER BAR
3 - REINFORCEMENT PLATE
4 - OPENING
5 - CHASSIS CROSSMEMBER
6 - STEERING GEAR
Fig. 63 Install Torque Converter Access Cover
1 - TORQUE CONVERTER ACCESS COVER
2 - BOLT
Fig. 64 Install Steering Gear
1 - STEERING GEAR
2 - BRACKET
VAAUTOMATIC TRANSMISSION - NAG1 21 - 43
AUTOMATIC TRANSMISSION - NAG1 (Continued)

(14) Install the transmission electrical connector
(2) (Fig. 65) from transmission and hang to the side.
Turn sealing ring (3) clockwise and connect plug con-
nection (2).
(15) Install the shift cable (Fig. 66) to the trans-
mission.
(a) Push shift cable onto the transmission shift
lever ball socket.
(b) Latch ball socket latch of cable.
(c) Clip shift cable retainer into retainer bracket.
(16) Install the cooler lines to the transmission.(a) Install the brackets for the oil cooler feed and
return lines (1) (Fig. 67) onto the engine oil pan
flange. Detail shows right side of motor. Position is
mirrored for the left side of engine.
(b) Attach the bracket for the cable retainer (4)
(Fig. 68) to the threaded shank of a engine oil pan
bolt (5).
(c) Install the bolts to hold the oil cooler lines (6)
to the left (Fig. 69) and right sides of transmission.
Torque the bolts to 34 N´m (254 ft.lbs.).
Fig. 65 Install Transmission Electrical Connector
and Cooler Line
1 - COOLER LINE
2 - TRANSMISSION ELECTRICAL CONNECTOR
3 - SEALING RING
Fig. 66 Install Shift Cable Onto Transmission
1 - SHIFT CABLE
2 - TRANSMISSION SHIFT LEVER
Fig. 67 Install Cooler Line Supports
1 - COOLER LINES
Fig. 68 Install Cable Support
1 - CABLE
2 - BOLT
21 - 44 AUTOMATIC TRANSMISSION - NAG1VA
AUTOMATIC TRANSMISSION - NAG1 (Continued)

Shift Pressure (p-S)
The shift pressure is determined by the shift pres-
sure regulating solenoid valve and the shift pressure
regulating valve. The shift pressure:
²Regulates the pressure in the activating shift
element during the shift phase.
²Determines together with the modulating pres-
sure the pressure reduction at the deactivating shift
element as regulated by the overlap regulating valve.
²Initializes 2nd gear in limp-home mode.
Modulating Pressure (p-Mod)
The modulating pressure influences the size of the
working pressure and determines together with the
shift pressure the pressure regulated at the overlap
regulating valve. The modulating pressure is regu-
lated at the modulating pressure regulating solenoid
valve, which is under regulating valve pressure. The
modulating pressure is variable and relative to the
engine load.Regulating Valve Pressure (p-RV)
The regulating valve pressure is regulated at the
regulating valve pressure regulating valve in relation
to the working pressure (p-A) up to a maximum pres-
sure of 8 bar (116 psi). It supplies the modulating
pressure regulating solenoid valve, the shift pressure
regulating solenoid valve and the shift valve pressure
regulating valve.
Shift Valve Pressure (p-SV)
The shift valve pressure (p-SV) is derived from the
regulating valve pressure (p-RV), is regulated at the
shift valve pressure regulating valve and is then
present at the:
²1-2 and 4-5 shift solenoid valve.
²3-4 shift solenoid valve.
²2-3 shift solenoid valve.
²Torque converter lockup solenoid valve.
²3-4 and 2-3 shift pressure shift valve.
The shift valve pressure (p-SV) controls the com-
mand valves via the upshift/downshift solenoid
valves.
Overlap Pressure (p-š)
The overlap pressure controls the shift component
pressure reduction during a shift phase. The pres-
sure in a shift element as it disengages is controlled
during the shift phase depending on engine load
(modulating pressure) and the pressure in the shift
element as it engages. The adjusted pressure is
inversely proportional to the transmission capability
of the shift element being engaged (controlled over-
lap).
Working Pressure Regulating Valve (Operating Pressure)
The working pressure regulating valve (Fig. 89) is
located in the valve housing of the shift plate. It reg-
ulates the primary pressure of the hydraulic system.
Torque Converter Lockup Clutch Regulating Valve
The torque converter lock-up clutch regulating
valve (Fig. 90) is located in the valve housing of the
electrohydraulic control module. The valve is respon-
sible for the hydraulic control of the torque converter
lockup clutch and distribution of the lubricating oil.
Overlap Regulating Valve
Each shift group is assigned one overlap regulating
valve (Fig. 91). The 1-2 / 4-5 overlap regulating valve
is installed in the shift valve housing; the 2-3 and 3-4
overlap regulating valves are installed in the valve
housing. The overlap regulating valve regulates the
pressure reduction during a shift phase.
Fig. 88 Electrical Control Unit
1 - N3 SPEED SENSOR
2 - PLUG CONNECTOR
3 - MODULATING PRESSURE REGULATING SOLENOID
4 - SHIFT PRESSURE REGULATING SOLENOID
5 - 1-2/4-5 SHIFT SOLENOID
6 - 3-4 SHIFT SOLENOID
7 - ELECTRICAL CONTROL UNIT
8 - TRANSMISSION TEMPERATURE SENSOR
9 - STARTER INTERLOCK CONTACT
10 - 2-3 SHIFT SOLENOID
11 - TORQUE CONVERTER LOCK-UP SOLENOID
12 - N2 SPEED SENSOR
VAAUTOMATIC TRANSMISSION - NAG1 21 - 83
ELECTROHYDRAULIC UNIT (Continued)

Overlap Regulating Valve
During the shift phase the pressure (Fig. 102) in
the deactivating shift actuator is regulated in rela-
tion to the engine load (modulating pressure) and the
pressure in the activating actuator. The regulated
pressure is inversely proportional to the transfer
capacity of the activating shift actuator (regulated
overlap).
Command Valve
When the end face is unpressurized (stationary
phase), the working pressure is directed to the actu-
ated shift element. If the end face of the commandvalve (Fig. 103) is subjected to the shift valve pres-
sure (p-SV) (shift phase), then the shift pressure is
switched to the activating element and the overlap
pressure is switched to the deactivating element.
Shift Valve Holding Pressure
The holding pressure shift valve (Fig. 104) is actu-
ated by the pressures present at the end face in the
actuators and a spring. It assigns the working pres-
sure to the actuator with the higher pressure (taking
into account the spring force and the effective surface
area). The other element of the shift group is then
unpressurized. The valve switches over only during
the shift phase and only at a certain pressure ratio
between the overlap pressure (p-š) and the shift
pressure (p-S).
Shift Pressure Shift Valve
When the multiple-disc brake B1 (3) is activated,
the working pressure (pa) is applied to the end face
of the 1-2 / 4-5 shift pressure shift valve (4) (Fig. 105)
via the command valve (1). Its shift state is main-
tained during the shift phase by substituting the
shift element pressure acting on its end face (and
which is variable during the shift phase) with a cor-
responding constant pressure. When the multi-plate
clutch K1 (2) is activated, the end face of the shift
valve is unpressurized during the stationary and
shift phases, so the shift state is maintained during
the shift phase in this case too.
Fig. 103 Command Valve
1 - HOLDING CLUTCH B1
2 - DRIVING CLUTCH K13 - 1-2/4-5 COMMAND VALVE
Fig. 102 Overlap Regulating Valve
1 - OVERLAP REGULATING VALVE
2 - ANNULAR SURFACE ON OVERLAP REGULATING VALVE
VAAUTOMATIC TRANSMISSION - NAG1 21 - 89
ELECTROHYDRAULIC UNIT (Continued)

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - EFFECTS OF
INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn the
fluid into foam. This aerates the fluid and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has three primary causes.
(1) Internal clutch slippage, usually caused by low
line pressure, inadequate clutch apply pressure, or
clutch seal failure.
(2) A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged main cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.
(3) Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²overheat that generates sludge (fluid break-
down)
²failure to replace contaminated converter after
repair
The use of non-recommended fluids can result in
transmission failure. The usual results are erratic
shifts, slippage, abnormal wear and eventual failuredue to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw-
ing the dipstick.
Engine coolant in the transmission fluid is gener-
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission, an overhaul is necessary.
The torque converter should be replaced whenever
a failure generates sludge and debris. This is neces-
sary because normal converter flushing procedures
will not remove all contaminants.
STANDARD PROCEDURE
STANDARD PROCEDURE - CHECK OIL LEVEL
(1) Verify that the vehicle is parked on a level sur-
face.
(2) Remove locking pin (1) (Fig. 136). Remove the
plate of the locking pin with a suitable tool and press
out the pin remaining in the cap downwards.
(3) Remove cap (2).
WARNING: Risk of accident from vehicle starting off
by itself when engine running. Risk of injury from
contusions and burns if you insert your hands into
the engine when it is started or when it is running.
Secure vehicle to prevent it from moving off by
itself. Wear properly fastened and close-fitting work
clothes. Do not touch hot or rotating parts.
Fig. 136 Remove Dipstick Tube Cap Lock
1 - LOCKING PIN
2 - TUBE CAP
3 - DIPSTICK TUBE
21 - 102 AUTOMATIC TRANSMISSION - NAG1VA
FLUID AND FILTER (Continued)

(4) Actuate the service brake. Start engine and let
it run at idle speed in selector lever position9P9.
(5) Shift through the transmission modes several
times with the vehicle stationary and the engine
idling
(6) Warm up the transmission, wait at least 2 min-
utes and check the oil level with the engine running.
Push the Oil Dipstick 8863A in up to the stop on the
electrohydraulic unit and pull out again, read off oil
level, repeat if necessary.
NOTE: The dipstick will protrude from the fill tube
approximately 75mm (3 inches) when installed.
(7) Check transmission oil temperature.
NOTE: The true transmission oil temperature can
only be read by a scan tool in REVERSE or any for-
ward gear position. (Refer to 21 - AUTOMATIC
TRANSMISSION- NAG1/TRANSMISSION TEMPERA-
TURE SENSOR/PARK-NEUTRAL SWITCH - OPERA-
TION)(8) The transmission Oil Dipstick 8863A has indi-
cator marks every 10mm. Determine the height of
the oil level on the dipstick and using the height, the
transmission temperature, and the Transmission
Fluid Graph (Fig. 137), determine if the transmission
oil level is correct.
(9) Add or remove oil as necessary and recheck the
oil level.
(10) Once the oil level is correct, install a new dip-
stick tube cap (2) (Fig. 138) and lock pin (1).
STANDARD PROCEDURE - TRANSMISSION
FILL
To avoid overfilling transmission after a fluid
change or overhaul, perform the following procedure:
(1) Verify that the vehicle is parked on a level sur-
face.
(2) Remove locking pin (1) (Fig. 139). Remove the
plate of the locking pin with a suitable tool and press
out the pin remaining in the cap downwards.
(3) Remove cap (2).
(4) Add following initial quantity of Shellt3403 to
transmission:
Fig. 137 NAG1 Transmission Fill Graph
VAAUTOMATIC TRANSMISSION - NAG1 21 - 103
FLUID AND FILTER (Continued)