The Range of 6 and 7 Speed Transmissions

The range of 6-speed automatic transmissions of ZF is now complete.

After the 6 HP 26 and the 6 HP 32, the 6 HP 19 is giving its debut in the new BMW 5-Series.

The developers at ZF, however, are not resting on their laurels. Based on this, they are presenting an engineering study concerning an automatic transmission featuring seven speeds At the IAA 2003.

The modular system of the range of 6-speed automatic transmissions permits in principle a high percentage of shared components, such as the mechatronics module, housing, Ravigneaux-type gear set, control units, oil pump and sump. With three 6-speed transmissions, ZF is in a position to cover the entire range of standard-size and full-size cars with 4, 6, 8 or 12-cylinder gasoline or Diesel engines. Drawing on this modular system, ZF engineers have developed a 7-speed transmission based on the 6-speed range using the Lepelletier principle, which is a well-proven technology on the market.

A wet starting clutch with dual-mass flywheel instead of a converter is a specialty of this 7 P transmission. This new transmission features very sporty and spontaneous gearshifts and is especially suited for modern Diesel engines. The extended spreading from 6.04 for six speeds to 7.28 permits improved acceleration behavior and a further reduction of emission and fuel consumption. The transmission has been designed for 600 Nm. Compared to a 5-speed automatic transmission; the 7 P- transmission is smaller and much lighter since fewer components are needed. The 7 P-transmission is installed in the housing of the 6-speed automatic transmission. At the request of the customer, however, it is possible to shorten the housing by another 4 centimeters, which is possible because of the omission of the converter.

ZF is the first driveline and chassis technology specialist worldwide to present a complete range of 6-speed automatic transmissions for FWD and RWD cars. A glance at the vehicles produced by ZF customers shows how successful this range of 6-speed automatic transmissions is: Audi A8, BMW 7 & 5- Series, Rolls Royce, Jaguar XJ, XK, S-Type and VW Phaeton.

Only 18 months passed between the introduction of the first 6-speed automatic transmission myTronic6, Type 6 HP 26, and production launch of the 6 HP 32 (up to 750 Nm) at year-end 2002. Now the youngest member of the myTronic6 range m) at year-end 2002. Now the youngest member of the myTronic6 range follows, the 6 HP 19 for lower torque levels of up to 350 Nm and first used in the new BMW 5-Series.

The 6-speed range is based on the Lepelletier principle, according to which the six speeds can be realized with 30 percent fewer components than is needed for traditional 5-speed automatic transmissions.

The result: Weight savings amounting to a total of about eleven kg for the 6 HP 26 and a more compact design requiring less space compared to preceding models.