1997 MERCEDES-BENZ ML350 piston

287 Technical data
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index Technical data
Model ML 320 (163 154)
1
ML 430 (163 172)
1
ML 55 AMG (163 174)
1
Engine112 113 113
Mode of operation 4-stroke engine,
gasoline injection4-stroke engine,
gasoline injection4-stroke engine,
gasoline injection
No. of cylinders688
Bore 3.54 in (89.90 mm) 3.54 in (89.90 mm) 3.82 in (97.00 mm)
Stroke 3.31 in (84.00 mm) 3.31 in (84.00 mm) 3.62 in (92.00 mm)
Total piston displacement 195.2 cu.in. (3199 cm
3) 260.6 cu.in. (4266 cm
3) 332.0 cu.in. (5439 cm
3)
Compression ratio 10:1 10:1 10.5:1
Output acc. to SAE J 1349 215 hp / 5600 rpm
(160 kW / 5600 rpm)268 hp / 5750 rpm
(200 kW / 5750 rpm)342 hp / 5500 rpm
(255 kW / 5500 rpm)
Maximum torque acc. to
SAE J 1349233 ft.lb / 3000 rpm
(315 Nm / 3000 rpm)288 ft.lb / 3000 rpm
(390 Nm / 3000 rpm)376 ft.lb / 2800 rpm
( 510 N m / 2 80 0 r p m )
Maximum engine speed 6000 rpm 6000 rpm 6000 rpm
Firing order 1-4-3-6-2-5 1-5-4-2-6-3-7-8 1-5-4-2-6-3-7-8
Poly-V-belt 2390 mm 2390 mm 2390 mm
1 The quoted data apply only to the standard vehicle. See an authorized Mercedes-Benz Light Truck Center for the corresponding data of all
special bodies and special equipment.

287
Technical data
Te ch n ica l
data
Instruments
and controls Operation Driving
Instrument
cluster display Practical hints Car care Index
Technical data
Model ML 320 (163 154)
1
ML 430 (163 172)
1
ML 55 AMG (163 174)
1
Engine 112 113 113
Mode of operation 4-stroke engine, gasoline injection 4-stroke engine,
gasoline injection 4-stroke engine,
gasoline injection
No. of cylinders688
Bore 3.54 in (89.90 mm) 3.54 in (89.90 mm) 3.82 in (97.00 mm)
Stroke 3.31 in (84.00 mm) 3.31 in (84.00 mm) 3.62 in (92.00 mm)
Total piston displacement 195.2 cu.in. (3199 cm
3) 260.6 cu.in. (4266 cm
3) 332.0 cu.in. (5439 cm
3)
Compression ratio 10:1 10:1 10.5:1
Output acc. to SAE J 1349 215 hp / 5600 rpm (160 kW / 5600 rpm) 268 hp / 5750 rpm
(200 kW / 5750 rpm) 342 hp / 5500 rpm
(255 kW / 5500 rpm)
Maximum torque acc. to
SAE J 1349 233 ft.lb / 3000 rpm
(315 Nm / 3000 rpm) 288 ft.lb / 3000 rpm
(390 Nm / 3000 rpm) 376 ft.lb / 2800 rpm
( 510 N m / 2 80 0 r p m )
Maximum engine speed 6000 rpm 6000 rpm 6000 rpm
Firing order 1-4-3-6-2-5 1-5-4-2-6-3-7-8 1-5-4-2-6-3-7-8
Poly-V-belt 2390 mm 2390 mm 2390 mm
1 The quoted data apply only to the standard vehicle. See an authorized Mercedes-Benz Light Truck Center for the corresponding d ata of all
special bodies and special equipment.

294 Technical dataEngine
EngineModel
ML 350 (163.157
1)
1The quoted data apply only to the standard vehicle. See an authorized Mercedes-Benz Light Truck Center for the corresponding data of all special bodies and special
equipment.
ML 500 (163.175)
1
Engine
112
113
Mode of operation
4-stroke engine, gasoline injection
4-stroke engine, gasoline injection
No. of cylinders
6
8
Bore
3.81 in (97.00 mm)
3.81 in (97.00 mm)
Stroke
3.31 in (84.00 mm)
3.31 in (84.00 mm)
Total piston displacement
227 cu in (3724 cm
3)
303 cu in (4966 cm
3)
Compression ratio
10:1
10:1
Output acc. to SAE J 1349
232 hp / 5750 rpm
(173 kW / 5750 rpm)
288 hp / 5600 rpm
(215 kW / 5600 rpm)
Maximum torque acc. to SAE J 1349
254 lb-ft / 3000-4500 rpm
(345 Nm / 3000-4500 rpm)
325lb-ft/2700rpm
(440 Nm / 2700 rpm)
Maximum engine speed
6000 rpm
6000 rpm
Firing order
1-4-3-6-2-5
1-5-4-2-6-3-7-8
Poly-V-belt
2370 mm
2370 mm

closed. The intake air must flow through the whole intake pipe. Its length is selected in such a way that the
pressure waves, produced by the inducting pistons, arrive at the right moment at the open intake valves for the
next induction stroke. The result is improved cylinder charge and thus an increase in torque.
At higher engine speeds (e.g. from 3900 rpm) the actuation to the variable intake manifold switchover valve is
interrupted - the variable flaps open as a result of the spring force. Through the shortened route the pressure
waves arrive in time even at higher rotational speeds before the closing of the intake valves to the combustion
chamber.
INTAKE MANIFOLD, DESIGN - GF09.20-P-3102-03A
Shown on ENGINE 112
Fig. 4: Identifying Intake Manifold Components
- Shown On Engine 112
The intake manifold is assembled out of several magnesium pressure castings. When fitted together, they
produce the individual intake manifolds and the air collecting volume. The parts are sealed off to each other by
plastic. The intake manifold cannot be disassembled.
The individual intake manifolds each approx. 800 mm long, are arranged in a spiral shape around the air
collecting volume. A single intake manifold is assigned to each cylinder.
Each single intake manifold has a further opening to the air collecting volume in the middle. These can be
opened or closed by means of variable flaps which pivot through approx. 60°.
The variable flaps are attached to steel shafts. One shaft is installed for each bank of c
ylinders. The

2001 Mercedes-Benz ML320
1998-2005 ENGINE Air Intake, Turbo Charging - 163 Chassis
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Saturday, October 02, 2010 3:16:57 PMPage 3 © 2006 Mitchell Repair Information Company, LLC.

Operation
If the piston (B1a) on multiple-disc brake B1 is subjected to oil pressure, it presses the internal and external
discs of the disc set together. See Fig. 44
. The front sun gear (v1) on the housing is locked via the internal
multiple-disc carrier (B1c). the front planetary gears (V2) roll on the front sun gear (V1).
If the rear multiple-disc brake (B2) is engaged via the piston (B2a), then this presses the disc set together. The
center sun gear (M1) is locked against the housing via the internal multiple-disc carrier (B2c). The center
planetary gears (m2) roll on the center sun gear (M1).
If the center multiple disc brake (B3) is engaged via the piston (B3a), then the rear planetary gear carrier (H3)
and the center hollow gear (M4) are locked. When the center multiple-disc brake (B3) is engaged the direction
of rotation reverses.
Multi-Plate Clutch, Location/Task/Design/Function

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Fig. 46: Multi-Disc Clutch, Function
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Operation
Front Multiple-Disc Clutch (K1) - If the piston (K1a) on the front multiple-disc clutch (k1) is subjected to oil
pressure, it presses the internal and external discs of the disc set together. See Fig. 46.
The front sun gear (V1) is connected to the front planetary gear carrier (V3) via the external multiple-disc
carrier (K1b) and the internal multiple-disc carrier (k1b) and the internal multiple-disc carrier (K1c). The front
planetary gear set is thus locked and turns as a closed unit.
Center Multiple-Disc Clutch (K2) - If the center multiple-disc clutch (K2) is engaged via the piston (K2a), the
piston compresses the disc set Via the internal multiple-disc carrier (K2b) and the center planetary gear carrier
(M3) on which the internal discs are seated, the front hollow gear (v4) of the front planetary gear set is
connected to the center hollow gear (M4) of the center planetary gear set. The front hollow gear (V4) and the
center hollow gear (M4) move at the same speed as the drive shaft (1).
Rear Multiple-Disc Clutch (K3) - If the rear multiple-disc clutch (K3) is engaged via the piston (K3a), then
this compresses the disc set. The center sun gear (M1) of the center planetary gear set is connected to the rear
sun gear (H1) of the rear planetary gear carrier via the external multiple-disc carrier (K3b) and internal multiple-
disc carrier (K3c). The center sun gear (M1) and the rear sun gear (H1) move at the same speed.
Upshift/Downshift Solenoid Valve, Location/Task/Design/Function

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Saturday, October 02, 2010 3:15:26 PMPage 89 © 2006 Mitchell Repair Information Company, LLC.

Fig. 106: Torque Converter Lockup Clutch, Function
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Operation
When actuated by the ETC control module (N15/3), oil pressure controlled by the torque converter lockup
PWM solenoid Valve (Y3/6y6) is directed through the input shaft (1) to the pressure chamber behind the piston
(16d). See Fig. 106
. The piston presses the clutch pack (16c) together and allows torque to be transferred
directly between the impeller (P) and turbine wheel (T). The torque converter lockup clutch is activated in 5th,
4th and 3rd gears in relation to the engine speed and engine load.
AUTOMATIC TRANSMISSION, FUNCTION
Transmission without touch shift. 722.6 in MODEL 163, 170, 202, 208, 210.
Transmission 722.6 in MODEL 129, 140.
Automatic transmission 722.6 is an electronically controlled 5-speed transmission with a lockup clutch in the
torque converter.
The ratios for the gear stages are achieved by three planetary gear sets. The 5th gear is designed with a step-up
ratio as an overdrive.
Shifting is initiated electronically. The gears are shifted by the corresponding combination of three
hydraulically actuated multi-plate brakes, three hydraulically actuated multi-disc clutches and two mechanical
freewheels.
Basically automatic transmission 722.6 with electronic control offers the following advantages:
Reduced fuel consumption
Improved shift comfort
More favorable gear steps as a result of 5 gears
Enhanced life and reliability
Reduced servicing costs
The electrohydraulic control unit is bolted onto the bottom of the transmission housing. The end of the
transmission is formed by an oil pan made of sheet steel.
The oil pressure for the converter lockup clutch and center multiple disc clutch is supplied via holes in the input
shaft. The oil pressure to the rear multiple-disc clutch is routed through the output shaft. The lubricating oil is
supplied and distributed by additional bore holes in both shafts. All bearing points of the gear sets as well as
freewheels and shift elements are supplied with lubricating oil.
The parking lock gear and drive flange are connected to the output shaft by gearing.
Freewheels F1 and F2 optimize shiftin
g. The front freewheel (F1) rests against the stator shaft extension on the

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Shifting 2nd gear with program selection "W" or "C" (depending on the production period).
Function
Start engine -
The working pressure (p-A) is formed, reaches via the holding pressure 2-3 shift valve, the command valve 2-3
and ball valve (33a) to the rear multi-disc clutch (K3) and via the command valve 3-4 (31c) to the end face of
the shift pressure 3-4 (29c) shift valve. The 3-4 shift pressure shift valve (29c) is moved against the force of the
spring towards the right. At the same time the 3-4 solenoid valve (Y3/6y4) is energized.
The ECT control unit (N15/3) monitors the engagement process via the reduced speed of the drive shaft as the
frictional connection of the rear multi-disc brake increases. When the speed drops to the specified level, the
ECT control module (N15/3) shuts off the power to the 3-4 shift solenoid valve (Y3/6y4). The spring chamber
of the shift valve B2 (26) is depressurized and switches downward. As a result the line to the opposed surface of
the rear multi-disc brake piston (B2b) is connected to the pressure maintaining valve (32). The pressure on the
opposed surface of the rear multi-disc brake piston (B2b) reduces to a residual pressure.
The 3-4 command valve (31c) moves to the left. The working pressure (p-A) reaches via the holding pressure
shift valve 3-4 (28c) and the command valve 3-4 (31c) to the piston of the rear multi-disc brake (B2a).
The activation sequence is complete; 1st gear is engaged (See Fig. 130
.
As a result shift valve pressure (p-SV) reaches the spring chamber of the shift valve B2 (26) and the end face of
the command valve 3-4 (31c).
The shift valve B2 (26) is held in the upper position and the 3-4 command valve (31c) switches towards the
right.
The working pressure (p-a) is replaced by the shift valve pressure (p-SV) at the end face of the shift pressure 3-
4 shift valve (See Fig. 131
).
Move Selector Lever From "N" To "D"
The selector lever (52) opens the shift pressure (p-S) feed connection from the ball valve (33b) with the shift
valve B2 (26). In the upper position of the shift valve B2 (26) shift pressure (p-S) reaches behind (p-S) the
piston of the multi-disc brake (B2a) and simultaneously to the opposed surface of the rear multi-disc brake
piston (B2b).
The rear multi-disc brake begins to close. See Fig. 132
.
The pressure on the opposed surface of the piston of the rear multi-disc brake (B2b) causes a gentle engagement
of the rear multi-disc brake.
Move Selector Lever From "N" To "R"
The selector valve (52) opens the connection of the feed of shift pressure (p-S) with the center multi-disc brake

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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