Product profile: ZF–AS Tronic lite
Following the popularity of our previous product profile on the AS-Tronic automatic transmission system, we’ve decided to write a profile about the transmission’s little brother – the AS-Tronic lite.
As the name suggests, the lite version is a compact version of the trusty full-size AS-Tronic transmission system used in a wide variety of large commercial vehicles.
A fully automatic 6-speed shift transmission, the AS-Tronic lite is a two pedalled gear shifter which negates the need for a clutch lever. The system eliminates the possibility for a lot of driver error by making incorrect gear changes a thing of the past. In this way, the transmission system reduces fuel consumption, protects the engine and ensures a long service life. The short shift-steps can also increase acceleration when drivers don’t want to hang around.
A smooth ride for light commercial vehicles
The AS-Tronic lite is used primarily in smaller passenger-transport vehicles like light coaches, shuttle/city services and school buses. Its popularity in person transporters owes a lot to the AS-Tronic’s automatic shifting system. AS-Tronic lite gives buses the smoothest gear transmissions, providing a level of comfort which is essential for passenger commuting.
Bus drivers don’t hog all the joy of a smooth ride though. AS-Tronic lite is also suitable for some smaller trucks which don’t require a full sized automatic transmission.
Benefits of an automatic AS-Tronic over traditional transmissions
- Fully automatic gear shifting, with the possibility of manual selection if required.
- Smooth, jolt-free ride for sitting and standing passengers.
- More efficient shifting to save fuel.
- Good reliability and long average service life.
- Reduced wear and tear.
Technical information
Technically, the AS-Tronic lite is quite complicated. The above video gives a good visual representation of how the system looks, and how the various components are connected to each other.
The ZF-AS Tronic lite transmission is a combined electronic-hydraulic-pneumatic shifted synchromesh transmission and automated dry clutch. The full system includes an electronic engine control unit and CAN communication which must be in place before the ZF-AS Tronic can be used. An automatic clutch replaces the clutch pedal and renders driver clutch operation unnecessary.
All this means the shift process varies considerably from other transmissions. ‘Shifting’ takes place in the electronic transmission control unit. The driver can choose to operate semi-automatically or in fully automatic mode. When in semi-automatic mode, the driver manually activates shifts by using a range selector. During fully automatic mode, gears are selected and shifted by the electronic transmission control unit, although the driver can intervene if so desired using the range selector.
Here at Ecodrive, we are big fans of ZF’s AS-Tronic lite transmission system, mainly because it is so easy to maintain. Ecodrive technical director Graham Evans praises it very highly.
He said: The AS-Tronic lite is one of the most reliable, maintenance-free transmission systems on the market. In particular I’m a fan of the clever electronics which not only eliminate driver error, but also the bad habits which can cause gear wear over extended periods.
“When one does come into our workshop its usually a breeze to fix, especially if the driver has recorded any error messages which appear. This cuts down fixing times by quite large margins.
“Talking to drivers, it’s also clear that the more you work with an AS-Tronic lite, the more efficient you can drive it.”