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lei Gt TRONIC
lveco is first on the market with ZF's AS-Tronic gearbox, shorter and lighter than an Ecosplit equivalent, and the company reckons that it can deliver substantial savings. Conservative hauliers might be difficult to convince—so what could persuade them?
Conventional automatic systems—even advanced types such as Allison's World Series—inevitably suffer from efficiency losses and a limited number of ratios. "Automated" systems such as Volvo's Geartronic and Scania's Opticruise avoid these by combining electronic gear selection with a servo-operated clutch and a conventional multi-speed synchromesh gearbox, allowing two-pedal control— although Opticruise retains the clutch pedal for low-speed manoeuvring.
lveco's EuroTronic gearbox is a semi-automatic variant of the ZE-built AS-Ironic, announced two years ago. Iveco has an exclusive deal to fit the non-synchro transmission for a year before it becomes available to other manufacturers. EuroTronic will be offered on EDC-equipped EuroStar and EuroTech models rated at 380hp and 470hp, reaching the UK market this September.
This is only the beginning: the system could he introduced across the range, wherever a manual or automatic box is used. Rut this depends on customer reaction, and whether the design is as reliable as a conventional box. lveco believes a programme of customer clinics and exhaustive testing has answered this question.
• Design
EuroTronic is not quite as novel functionally as Voivo's Geartronic—it offers only clutchless gear selection with a couple of automatic programmes, rather than true "hands-off-the stick" driving. Rut mechanically it is more interesting—the shape of things to come, perhaps.
Smooth gear engagement requires a precise relationship between input and output shaft speeds: while a conventional synchromesh box employs mechanical slippage to achieve this, AS-Ironic contmls engine speed electronically. This obviously relies on engine and road-speed sensors, and an interface between the engine and gearbox controls, which is only practical if the engine is equipped with EDC (Electronic Diesel Control).
The box dispenses with synchromesh cones on the main ratios (engaged using dogs) although the rangechange and splitter gears are conventionally synchronised. Still, dispensing with synchronising cones saves more than enough weight to offset the addition of pneumatic actuators for gear selection. These four actuators are mounted together in a single "transmission shift unit" mounted on top of the box, which can be removed with the rest of the aluminium gearbox housing in situ. The clutch is a conventional single dry plate type, but there's no pedal: instead, another pneumatic actuator is controlled by the gearbox electronics.
The net result of the new design—and some refinement of existing components—is that the 16-speed EuroTronic is 56kg lighter and 62mm shorter than ZF's equivalent allsynchromesh Ecosplit 3 box, the 16S-221.
• Development and installation
The box is straightforward mechanically— but Paolo Pignato, Iveco's chief marketing manager for heavy trucks, is clear: "T want you to call it a system, not just a gearbox:' He emphasises that Iveco worked closely with ZF to optimise the control system, and that this will effectively lengthen the firm's one-year head start over MAN and Daf.
Engineer Katalin Tihanyi explains that the relationship between engine and gearbox is complicated: sensors measure not just engine, transmission and road speed, but also calculate rate of change of speed to compensate for loading and gradient—information is also gathered from the ABS/ASR system and the Intarder, if fitted.
Tihanyi reckons that about half of the development effort went into ensuring that the system would he fault-tolerant. For example, if the transmission output speed sensor fails, an error code flashes on the dash display but the box will still change adequately.
A more serious problem need not stop the vehicle: if the gear split signal is interrupted, the box will still change through
whole gears. Even if the entire selector interface fails, two forward gears and one reverse gear may still be available.
Mechanically, installation is simple—probably easier than with a conventional box. There is no clutch pedal, so no hydraulic supply to the clutch, while the only connection to the "gearlever" is electronic so that the cab can be soundproofed more effectively.
• Running costs
The initial cost of EuroTronic is higher than for a conventional box: the premium on list price is likely to be about £2,500 (plus another £2,500 for the optional Intarder). But there should be no penalties in operation: in fact, Iveco claims that running costs are potentially lower—and that the payback time for a EuroTronic box could be as little as 18 months.
Pignato calculates the savings by assuming that the payload is increased—a fair point--and that the system will reduce a mediocre driver's fuel consumption by around 10%. This is a bold claim (and he admits that a skilled driver will probably see no improvement) but our experience suggests that the system could level out fleet fuel consumption figures.
Iveco is more confident of another saving: the company reckons the EuroTronic's clutch life should be around a million km—about twice that of a manual unit—regardless of the driver's skill. The air-operated clutch is effectively self-adjusting, but it uses conventional parts, and replacement is a routine operation.
• Marketing
Adopting the ZFbuilt system is a change of direction for Iveco, which has been offering a semi-automatic option for some years. But the company is dropping Eaton's SAMT, which was the standard fitting to the UKspec EuroStar 520. Paolo Pignato admits that Iveco has sold fewer than 500 SAWequipped trucks since their launch in 1992.
The market for automatic boxes is pretty limited at present (only about 3% of heavy trucks sold in Europe), but Pignato reckons EuroTronic will make up 8-15% of EuroTech and EuroStar sales next year.
EuroTronic is simple enough to learn, but hauliers tend to be conservative when it comes to new systems. Iveco has run customer clinics in which fleet drivers compared EuroTronic with other automatic and semiautomatic systems; they indicated that the system should be acceptable even for fleets which employ agency drivers.
Now it's up to the customers...
El by Toby Clark