Chrysler Announces Shift to ZF 8HP Eight-Speed Automatic Transmission

Chrysler and German driveline and chassis component supplier ZF have reached an agreement that will see ZF supply and license manufacturing rights to its 8HP eight-speed automatic transmission for use in Chrysler vehicles, including potential application in Ram full-size pickups.

The 8HP gearbox is already used in BMW's 760Li and the 5 Series GT and the new Rolls-Royce Ghost.

The transmission uses four planetary gearsets and five shifting elements (multi-disc clutches and brakes). It's not a dual-clutch transmission but ZF says shifts can be performed in only 200 milliseconds. It can manage up to 516 pounds-feet of torque.

Using an eight-speed transmission has two big advantages: improved fuel economy and shorter gear steps between cogs, for quicker acceleration and smoother shifts.

ZF says the eight-speed setup is 6 percent more fuel efficient than ZF's old 6HP six-speed automatic and can add another 11 percent gain in efficiency when combined with an optional start/stop feature that automatically shuts the engine off when the vehicle stops and restarts it when the brake is released.

“The new eight-speed automatic transmission will offer our customers refinement and comfort while achieving greater fuel economy and performance,” said Paolo Ferrero, senior vice president of Chrysler's powertrain division. “We look forward to integrating the new transmission into future Chrysler Group products and welcome its contribution to a corporate fuel economy improvement of more than 25 percent by 2014.”

Chrysler will initially import 8HP transmissions from Europe until it finishes a $300 million revamp of its existing transmission manufacturing and casting facilities in Kokomo, Ind. to produce the 8HP there, starting in 2013.

Indiana Transmission Plant 1 currently makes the 545RFE "Orion" five-speed automatic transmission for Dodge Dakota and 5.7-liter Hemi-powered Ram full-size pickups and the 68RFE six-speed auto for Heavy Duty pickups with the 6.7-liter Cummins diesel engine (which produces more torque than the 8HP can currently manage).

[Sources: Chrysler, ZF]