2005 MERCEDES-BENZ SPRINTER check engine

(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)

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)

(a) If only fluid and filter were changed, add5.0
L (10.6 pts.)of transmission fluid to transmission.
(b) If transmission was completely overhauled,
torque converter was replaced or drained, and
cooler was flushed, add7.7 L (16.3 pts.)of trans-
mission fluid to transmission.
(5) Check the transmission fluid (Refer to 21 -
TRANSMISSION/AUTOMATIC - NAG1/FLUID -
STANDARD PROCEDURE) and adjust as required.
STANDARD PROCEDURE - FLUID/FILTER
SERVICE
(1) Run the engine until the transmission oil
reaches operating temperature.
(2) Raise and support vehicle.(3) Remove the torque converter drain plug access
plug from the bottom of the torque converter hous-
ing.
(4) Rotate the engine clockwise until the torque
converter drain plug (Fig. 140) is aligned with the
access hole.
NOTE: Clean the area around the drain plug to pre-
vent dirt from entering the torque converter.
(5) Using a suitable drain pan to catch the fluid,
remove the torque converter drain plug and allow the
torque converter to drain completely.
(6) Inspect the torque converter drain plug seal
(Fig. 140). Replace the seal if necessary.
(7) Install the torque converter drain plug. Tighten
the drain plug to 14 N´m (10 ft.lbs.).
(8) Install the torque converter drain plug access
plug into the bottom of the torque converter housing.
(9) Using a suitable drain pan to catch the fluid,
remove the transmission oil pan drain plug (Fig. 140)
and allow the oil pan to drain completely.
(10) Inspect the transmission oil pan drain plug
seal. Replace the seal if necessary.
(11) Install the transmission oil pan drain plug.
Tighten the drain plug to 20 N´m (15 ft.lbs.).
(12) Remove the bolts and retainers (Fig. 140)
holding the oil pan to the transmission.
(13) Remove the transmission oil pan and gasket
from the transmission.
Fig. 138 Dipstick Tube Cap Components
1 - LOCKING PIN
2 - TUBE CAP
3 - DIPSTICK TUBE
Fig. 139 Remove Dipstick Tube Cap Lock
1 - LOCKING PIN
2 - TUBE CAP
3 - DIPSTICK TUBE
Fig. 140 Fluid/Filter Service Points
1 - OIL FILTER
2 - OIL PAN GASKET
3 - OIL PAN
4 - RETAINER
5 - BOLT
6 - OIL PAN DRAIN PLUG
7 - SEAL
8 - TORQUE CONVERTER DRAIN PLUG
9 - SEAL
21 - 104 AUTOMATIC TRANSMISSION - NAG1VA
FLUID AND FILTER (Continued)

(8) Inspect axial play (Fig. 203) between shim (10)
and retaining ring (11). Check axial play9S9between
shim (10) and retaining ring (1) using a feeler gauge.
Clearance should be 0.15-0.6 mm (0.006-0.024 in.).
Shims are available in thicknesses of 3.0 mm (0.118
in.), 3.4 mm (0.134 in.), and 3.7 mm (0.146 in.).
Adjust as necessary
NOTE: During the test, apply a contact force by
hand to K3 in the direction of the arrow.
SHIFT MECHANISM
DESCRIPTION
The automatic transmission is operated with the
help of a shift lever assembly (SLA) located in the
center console. There are four positions to which the
selection lever can be shifted: P, R, N, D. In addition,
the selector lever can be moved sideways (+/-) in posi-
tion9D9to adjust the shift range.
All selector lever positions, as well as selected shift
ranges in position9D9, are identified by the SLA. The
information is then sent to the transmission control
module (TCM) via a hardwire connection. At the
same time, the selector lever positions9P9,9R9,9N9
and9D9are transmitted by a shift cable to the selec-
tor shaft in the transmission.
The SLA is comprised of the following functions:²Key lock:Depending on the selector lever posi-
tion, the ignition lock is locked/unlocked, i.e., the
ignition key can be removed only if the selector lever
is in position9P9. A park lock cable is used to perform
this function.
²Park lock:The selector lever is not released
from postion9P9until the brake pedal has been
applied and the ignition key is in driving position.
Shift lock is controlled by the brake light switch in
conjunction with a locking solenoid in the SLA. As
soon as the brake pedal is applied firmly, the locking
solenoid is retracted to unlock the selector lever. If
the selector lever cannot be moved out of position9P9
due to a malfunction, the shift lock function can be
overriden (see operator's manual).
²Reverse inhibitor:As soon as the vehicle
speed exceeds approx. 4 mph, it is no longer possible
to move the selector lever from position9N9to posi-
tion9R9.
OPERATION
With the selector lever in position9D9, the trans-
mission control module (TCM) automatically shifts
the gears that are best-suited to the current operat-
ing situation. This means that shifting of gears is
continuously adjusted to current driving and operat-
ing conditions in line with the selected shift range
and the accelerator pedal position. Starting off is
always performed in 1st gear.
The selector lever positions are determined by the
slider position of a potentiometer in the shift lever
assembly (SLA). The shift pattern diagram (position
display) and the program selector are illuminated by
the LEDs.
The current selector lever position or, if the shift
range has been limited, the current shift range is
indicated in the LCD display in the instrument clus-
ter.
The permissible shifter positions and transmission
operating ranges are:
²P = Parking lock and engine starting.
²R = Reverse.
²N = Neutral and engine starting (no power is
transmitted to the axles).
²D = The shift range includes all forward gears.
²4= Shift range is limited to gears 1 to 4.
²3= Shift range is limited to gears 1 to 3.
²2= Shift range is limited to gears 1 to 2.
²1= Shift range is limited to the 1st gear.
The shift range can be adjusted to the current
operating conditions by tipping the selector lever to
the left-hand side (9-9) or the right-hand side (9+9)
when in position9D9. If the shift range is limited, the
display in the instrument cluster indicates the
selected shift range and not the currently engaged
gear.
Fig. 203 Check Center and Rear Planetary End-Play
1 - DRIVING CLUTCH K3
2 - THRUST WASHER
3 - SHIM
4 - AXIAL NEEDLE BEARING
5 - RETAINING RING
6 - OUTPUT SHAFT WITH CENTER PLANETARY CARRIER
VAAUTOMATIC TRANSMISSION - NAG1 21 - 133
PLANETARY GEARTRAIN (Continued)

TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and
turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine's piston and friction
material (Fig. 231) to the front cover, a total con-
verter engagement can be obtained. The result of this
engagement is a direct 1:1 mechanical link between
the engine and the transmission.
The clutch can be engaged in second, third, fourth,
and fifth gear ranges.
The TCM controls the torque converter by way of
internal logic software. The programming of the soft-
ware provides the TCM with control over the torque
converter solenoid. There are four output logic states
that can be applied as follows:
²No EMCC
²Partial EMCC
²Full EMCC
²Gradual-to-no EMCCNO EMCC
Under No EMCC conditions, the TCC Solenoid is
OFF. There are several conditions that can result in
NO EMCC operations. No EMCC can be initiated
due to a fault in the transmission or because the
TCM does not see the need for EMCC under current
driving conditions.
PARTIAL EMCC
Partial EMCC operation modulates the TCC Sole-
noid (duty cycle) to obtain partial torque converter
clutch application. Partial EMCC operation is main-
tained until Full EMCC is called for and actuated.
During Partial EMCC some slip does occur. Partial
EMCC will usually occur at low speeds, low load and
light throttle situations.
FULL EMCC
During Full EMCC operation, the TCM increases
the TCC Solenoid duty cycle to full ON after Partial
EMCC control brings the engine speed within the
desired slip range of transmission input speed rela-
tive to engine rpm.
GRADUAL-TO-NO EMCC
This operation is to soften the change from Full or
Partial EMCC to No EMCC. This is done at mid-
throttle by decreasing the TCC Solenoid duty cycle.
REMOVAL
(1) Remove transmission and torque converter
from vehicle.
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive flats for sharp
edges, burrs, scratches, or nicks. Polish the hub and
flats with 320/400 grit paper or crocus cloth if neces-
sary. The hub must be smooth to avoid damaging the
pump seal at installation.
(1) Lubricate oil pump seal lip with transmission
fluid.
Fig. 231 Torque Converter Lock-up Clutch
1 - TURBINE
2 - IMPELLER
3-STATOR
4 - INPUT SHAFT
5 - STATOR SHAFT
6 - PISTON
7 - COVER SHELL
8 - INTERNALLY TOOTHED DISC CARRIER
9 - CLUTCH PLATE SET
10 - EXTERNALLY TOOTHED DISC CARRIER
21 - 146 AUTOMATIC TRANSMISSION - NAG1VA
TORQUE CONVERTER (Continued)

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRESSURE
GAUGES
A quality air pressure gauge is recommended to
check tire pressure. After checking the air pressure,
replace valve cap finger tight.
DIAGNOSIS AND TESTING - TIRE NOISE OR
VIBRATION
Radial-ply tires are sensitive to force impulses
caused by improper mounting, vibration, wheel
defects, or possibly tire imbalance.
To find out if tires are causing the noise or vibra-
tion, drive the vehicle over a smooth road at varying
speeds. Note the noise level during acceleration and
deceleration. The engine, differential and exhaust
noises will change as speed varies, while the tire
noise will usually remain constant.
DIAGNOSIS AND TESTING - TREAD WEAR
INDICATORS
Tread wear indicators are molded into the bottom
of the tread grooves. When tread depth is 1.6 mm
(1/16 in.), the tread wear indicators will appear as a
13 mm (1/2 in.) band (Fig. 14).
Tire replacement is necessary when indicators
appear in two or more grooves or if localized balding
occurs.
DIAGNOSIS AND TESTING - TIRE WEAR
PATTERNS
Under inflation will cause wear on the shoulders of
tire. Over inflation will cause wear at the center of
tire.Excessive camber causes the tire to run at an
angle to the road. One side of tread is then worn
more than the other (Fig. 15).
Excessive toe-in or toe-out causes wear on the
tread edges and a feathered effect across the tread
(Fig. 15).
DIAGNOSIS AND TESTING - TIRE/VEHICLE
LEAD
Use the following Vehicle Lead Diagnosis And Cor-
rection Chart to diagnose and correct a vehicle lead
or drift problem (Fig. 16).
Fig. 14 Tread Wear Indicators
1 - TREAD ACCEPTABLE
2 - TREAD UNACCEPTABLE
3 - WEAR INDICATOR
Fig. 15 Tire Wear Patterns
22 - 8 TIRES/WHEELSVA
TIRES (Continued)