In many fleets, traditional manual transmissions are becoming a thing of the past. With more new drivers joining fleet ranks, easier to operate automated manual transmissions (AMTs), along with full automatics, are gaining in popularity. These transmissions also help all drivers—novice and veteran alike— improve fuel economy and safety.
Full control
Eaton’s newest automated transmission models are UltraShift Plus gearboxes available for linehaul and vocational use. Built on the Fuller 10-speed manual, UltraShift Plus transmissions use an electronic clutch actuator and shift selection software to make shift decisions based on grade, vehicle weight, engine torque and throttle position. Automatic, manual and low modes offer the driver full control. In manual mode, the driver can override computerized shifts on demand. Using low mode can help maximize engine braking.
The UltraShift Plus Linehaul Series is a fully automated two-pedal design that features a Hill Start Aid, which prevents unintended roll back or roll forward when a grade exceeds 1%, Skip Shifting to help increase acceleration and achieve cruising speed quickly and an optional Creep Mode that enables the driver to move the vehicle at less than 1 ft. per second.
The Eaton transmission lineup also includes the Procision seven-speed dual-clutch model for medium-duty trucks. A dual-clutch transmission consists of two independent but interlocked manual transmissions, each with its own independent clutch. Electronically controlled and hydraulic-actuated gear changes are achieved by pre-selecting the correct gear and “swapping” torque between the two clutches.
Driving modes
The Detroit DT12 automated manual transmission is available in 12-speed direct and overdrive versions. The DT12 combines an automated clutch with a computer-controlled pneumatic shift actuator that engages the clutch and shifts the transmission. Several options of driving modes, for use depending on terrain and specific application needs, are offered in the DT 12, including Performance Mode, Eco Mode and Creep Mode for low-speed maneuverability.
The DT12 also features pedal kick down capability to allow drivers to increase acceleration when passing or driving on uphill grades, and eCoast, which helps maximize fuel efficiency by allowing the vehicle to coast down grades at idle speed while electronics ensure safe operation. DT12 transmissions also have a Skip Shift feature to automatically skip unnecessary gears, and incorporate variable-speed cruise control, which allows the engine brake to regulate speed.
Integrated design
Volvo I-Shift is a 12-speed, two-pedal, automated mechanical transmission designed to integrate with all Volvo engines. I-Shift continuously monitors changes in grade, vehicle speed, acceleration, torque demand, weight and air resistance, and automatically selects the best gear. Features of I-Shift include a grade sensor, Kick-Down Mode for power and acceleration, Performance Mode for gradeability and a Brake Program Mode for maximum retardation. An optional feature called Eco-Roll will also help improve fuel economy in top gear.
Exclusive offering
The Mack mDRIVE transmission offered exclusively by the OEM in Pinnacle model tractors is a 12-speed automated manual transmission. Offered in direct drive and overdrive versions, mDRIVE is designed to be used with Mack MP Series Engines. mDRIVE continuously monitors changes in grade (up and down), vehicle speed, throttle position, acceleration, torque demand and combined vehicle weight, and automatically selects the best gear to optimize fuel economy at any desired road speed. Mack mDRIVE transmissions also feature two-speed reverse and are available with single and dual rear transmission PTO mounting options.
Class 8 automatic
For fleets requiring a fully automatic transmission in an on-highway tractor, Allison offers its Highway Series models. The all-new Allison TC10 is engineered specifically for Class 8 tractor applications. The fully automatic TC10 engages the torque converter only at launch, Allison notes, and with the manufacturer’s Power Technology maintains power to the drive wheels.
Other features of the new Allison TC10 automatic include EcoCal, which provides lower shift points and less shift cycling, Dynamic Shift Sensing to automatically select gears based on the vehicle’s actual payload and the grade on which it is operating, Neutral at Stop to eliminate load on the engine when the vehicle is at a full stop, and Acceleration Rate Management that controls engine torque based on the vehicle’s grade and load.
For more information about the range of automated and automatic transmissions available for on-highway vehicles:
Allison Transmission—www.allisontransmission.com
Detroit—www.demanddetroit.com/transmissions
Eaton—www.roadranger.com/rr/ProductsServices/ProductsbyCategory/
Transmissions/UltraShiftPLUS/index.htm
www.roadranger.com/rr/ProductsServices/ProductsbyCategory/
Transmissions/procision/index.htm
Mack Trucks—www.macktrucks.com/powertrain-and-suspensions/transmissions/mdrive
Volvo Trucks—www.volvotrucks.com/trucks/na/en-us/
products/powertrain/ishift/pages/ishift_ilf.aspx
