Voith DIWA®. 3 E automatic transmissions in Mercedes-Benz busesAutomatic neutral switch ANS when vehicle is at a halt Oil change intervals every 120,000 km, partly synthetic oils may be used (original filling ex works).

AUTOMATIC

Voith Turbo

The DIWA principle has proven itselfbut stays young:

The long DIWA driving range – whereothers have to shift gears (up to 50%more frequently), the DIWA transmis-sion holds its own.

This is comfortable and safer for stand-ing passengers; it also means lesswear on clutch plates and hence longerservice life.

Driving and braking with one circuit –and therefore fast response and pre-cise adjustment of the retardationeffect. The latter is achieved by con-trolled converter drainage.

Voith DIWA� Transmissions –Quality engineering

DIWA transmissions are continu-ously adapted to the latest technicaldevelopments in the commercialvehicle sector.

The transmissions and gear-shiftingprogrammes are adapted to the environmentally friendly low-emissionEURO 3 engines.

An electronic-hydraulic control systemimproves the gear-shifting quality of thetransmission in such a way thatchanges from one gear to the next arevirtually imperceptible.

As far as CAN is concerned, Voith Turbo is the first manufacturer of trans-missions worldwide who has been utilising this technology for years inseries-manufactured control systems.

An acceleration-dependent gear-shift-ing programme measures the acceler-ation and the load conditions of the busand automatically selects the most eco-nomical gear-shifting points. One gear-shifting programme is sufficient for alloperating conditions. The unique PCdiagnosis system controls and recordsthe transmission functions whether thebus is driving or stopping. This includesthe facility of monitoring the main oper-ation data.

Other advantages are the integration ofthe filter in the transmission housing,the smaller stainless steel heatexchanger in design for longer servicelife, the further development of the tor-sional vibration damper for lowerengine speeds, in order to reduce fuelconsumption, as well as the automaticANS neutral stage which separatesengine and transmission completelywhen the vehicle is at a halt. Mainte-nance intervals are now every 60,000kilometres, or – if partly or fully syn-thetic oils are used – every 120,000kilometres.

Braking stage l

Bra

king

pow

erTr

actio

n

1st gear(DIWA range)

4th gear

2nd gear

3rd gear

lll

0

ll

0 Driving Speed

Driving Speed

Eng

ine

outp

ut

0

Hydraulicpart

Mechanicalpart

Gear shifting1-2

Start-up range(DIWA range)

Start-up range(Torque converter transmission)

2nd gearhydr./mech.

0

1st gearhydr.

Shifting into1st gear

hydr./mech.

Shifting into2nd gear

hydr./mech.

1st gearmech.E

ngin

e ou

tput

Voith DIWA transmission

Competitive transmission

Voith principle:Driving and braking in one circuit

Braking:Retarder function with the converter.

Driving:Power split with differential converter.

The heart of the transmission is thehydrodynamic converter, acting as acounter-rotating torque converter. Situ-ated in front of it are the pump brake, thelock-up clutch, the differential gearboxfor power-splitting, the input clutch and,with DIWA four speed transmissions,the clutch for the fourth gear which isdesigned as overdrive. Behind the con-verter, an epicyclical gear combines thehydrodynamic and the mechanical pow-ers. The final epicyclical gear set (7) isfor reversing and activating the retarderduring braking.

A hydraulic torsional vibration damperat the transmission input side effective-ly absorbs engine vibrations. Gearchanges are carried out electro-hydraulically with patented solenoidvalves; the gear-shifting commands aregiven by the digital control system. Theheat exchanger of Voith automatictransmissions is integrated in the cool-ing circuit of the engine.

The control concept:Micro-processor control

� Digital processing of electric enginesignals such as EDC, electronicthrottle control etc.

� The adaptive control systemensures automatic adjustment toengine and vehicle and is there-fore a prerequisite for continuously high gear-shifting quality throughoutthe entire service life of the unit.

� Easy data exchange allows adaptation to new conditions (engine, vehicle, driving conditions).

� CAN-compatible� PC-based diagnosis system

DIWAgnosis enables accurate diagnosis of transmission condition and efficient failure search

� Compatible with Mercedes-Benz STAR diagnosis system.

� Operating data storage allows collection of key vehicle data.

Design and mode of operationof DIWA� transmissions

Illustration: Four-speed DIWA-transmission

1 Counter-rotating torque converter

2 Impeller brake3 Lock-up clutch4 Differential gear5 Input clutch6 Epicyclic gear set7 Epicyclic gear set for reverse

gear and retarder8 Torsional vibration damper9 Heat exchanger

10 4th gear clutch (only D 854.3E/D 864.3E)

98 5 4 3 2 1 7610

1 Push-button switch2 Pedal brake valve3 Accelerator4 Electronic control unit5 Level converter6 Diagnosis via PC

IES-CAN, FR

1

23

6

5

4

CITARO

CITARO L

CITARO G

CITARO

CITARO G

CITARO L

CITARO

CITARO G

CITARO

CITARO G

CITARO L

CITARO L

v [km/h]

101918377

10191837765

101918377

101918377

91837765

918377

Stadt/Regional

City/Suburbs

EngineOM 906 hLA [kW]

180/205180/205180/205180/205

205205205

205205

205180/205180/205180/205

205205205

205205

EngineOM 457 hLA[kW]

185/220/260185/220/260185/220/260185/220/260

185/220/260185/220/260185/220/260185/220/260185/220/260

185/220/260185/220/260185/220/260185/220/260

185/220/260185/220/260185/220/260185/220/260

220/260185/220/260185/220/260185/220/260

220/260185/220/260185/220/260

iA

5,275,776,217,38

5,776,217,38

5,776,21

5,275,776,217,37

5,776,217,37

5,776,21

iA

4,725,275,776,21

4,725,275,776,217,38

4,725,275,776,21

4,725,275,776,21

5,275,776,217,38

5,275,776,21

City/Suburbs

v [km/h]

119108101

85

108101

85

108101

119108101

85

108101

85

108101

4

Automatic transmissions forMercedes-Benz Citaro buses

Criteria for four-stage transmissionsSpeed v [km/h] at nominal engine speed related to current MB axle series iA

preferablycity buses

INTEGRO, INTEGRO L

iA

4,305,225,88

EngineOM 457 hLA[kW]

185/220/260185/220/260185/220/260

v [km/h]

1219988

Regional

EngineOM 457 hLA[kW]

185/220/260185/220/260

185/220/260

185/220/260

CITARO Ü

iA

4,374,72

4,72

4,725,27

iA

5,275,776,21

5,776,21

5,776,21

v [km/h]

109101

101

10191

v [km/h]

119108101

108101

108101

EngineOM 906 hLA[kW]

205205205

205205

205205

CITARO LÜ

CITARO GÜ

Regional Regional

Automatic transmissions forMercedes-Benz Citaro Ü regional buses

Criteria for four-stage transmissionsSpeed v [km/h] at nominal engine speed related to current MB axle series iA

Automatic transmissions forMercedes-Benz Integro regional buses

Criteria for four-stage transmissionsSpeed v [km/h] at nominal engine speed related to current MB axle series iA

5

G16

90 e

3/

03

1000

M

SW

/WA

P

rinte

d in

Ger

man

y.D

imen

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s an

d ill

ustr

atio

ns n

on-c

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ittal

, sub

ject

to c

hang

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Voith DIWA®. 3 E automatic transmissions in Mercedes-Benz buses

Voith automatic transmissions can beeasily installed in all Mercedes-Benzbuses. Transport operators appreciatethe reliability, the consistent gear-shifting comfort and the optimumadjustment to environmentally friendlylow-emission engines. To date, over100,000 DIWA transmissions havebeen delivered.

Voith Turbo GmbH & Co. KGProduct Group “Commercial Vehicle Transmissions”P.O. Box 2030D-89510 Heidenheim/GermanyPhone 0049 (73 21) 37-82 49Fax 0049 (73 21) 37-75 04E-mail: DIWA-Getriebe@voith.comwww.voithturbo.com

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6

1 O 405, Köln Transport2 Citaro, Duisburg Transport3 Citaro, Solingen Transport4 Citaro, Aschaffenburg Transport5 Citaro, Wiesbaden Transport6 Citaro, Rheinbahn Transport7 Citaro, Kiel Transport8 Citaro, Graz Transport9 Citaro, London Transport

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1

2

8

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