UK has to wait for Geartronic debut
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• At the beginning of next year Volvo goes into series production with its Geartronic automatic gearshift system (CM 4-10 July).
The system is a development of the G7-EGS bus gearbox. based on the conventional Volvo SR1700 12-speed gearbox. It uses the standard dry-plate clutch but does away with the clutch pedal: a computer controls gearshifts electro-pneumatically.
Initially Geartronic may only be specified as an option with Volvo's new range of 10, 12 and 16-litre low-emission engines fitted with EDC, an electronically controlled diesel fuel pump, on left-hand drive models (CM 6-12 June). A few automated gearboxes have been supplied to Swedish operators in recent months, but once again the British market place is left at the end of the queue with no firm date for availability.
With EDC and Geartronic, cruise control is standard and, using high engine revs, the engine brake is made to operate more effectively.
Special order
Volvo also offers the Powertronic, an automatic gearbox with a torque converter and integrated retarder. It was originally developed for Volvo BM's heavy-duty A35 dumper, but more recently has been installed in a number of Volvo trucks to special order.
With Powertronic gear changes occur without interruption to torque in the driveline — with Geartronic changes are made in the same way as a manual gearbox.
Last week CM travelled to the south of Sweden where we were able to assess the merits of the new transmissions.
We first drove a 22m 56tonne F16 6x4 drawbar logging rig fitted with the 12-speed range-change SR2000 synchromesh manual transmission.
Little effort
Starting in first we were able to move up the range using whole gears in the lower part of the box and on even ground only needed to use the splitter in the higher range. Gear shifting was smooth and quick. The clutch pedal took little effort to depress fully and the lever movement was light.
The vehicle's length was no problem. It was very manoeuvr able; even on 90° turns trailer cut-in remained minimal and on only narrow country roads was it necessary to swing slightly wide on the bends.
The Geartronic transmission was fitted to a 24m F12 Imperial 6x2 powered drawbar combination running at 56 tonnes GVW (the Imperial's Nordic specification included full air suspension and leather edged trim inside the cab).
The mechanical gear shift is replaced by a Volvo passenger car lever fitted with a micro shift and fascia-mounted display to indicate the various settings. The gearshift pattern is the same as for the manual SR1700 gearbox so the bottom three split ratios can be selected manually. Alternatively an additional position marked "A" for automatic drive allows all six splitter gears to be selected automatically.
On start up the automatic mode selects second gear but on production models this will probably be changed to first. A button on the gear console allows the driver to choose between economy mode, which contains engine revs to the green sector on the rev counter; or power, which allows a wider use of the engine's power.
A throttle kickdown facility allows intermediate use of the power mode, and if engine loading exceeds a set level the system automatically switches to the power mode.
Gear changing is very smooth and probably quicker than can be achieved manually. The only time it sounded a bit rough was changing down as the vehicle slowed without any load on the driveline.
Engine braking was more effective than on any other Volvo we have tested. The engine management system automatically makes use of high engine revs, and if they climb into the red it takes appropriate action by changing up a gear. Cruise control can be useful on lightly trafficked motorways but on country roads the engine often picks up on entering a bend when the driver's natural inclination may be to lift off.
While Geartronic has obvious potential for distribution vehicles, Volvo is introducing it on its more expensive models where the cost (about £5,500) represents a smaller fraction of the overall price. In any case EDC will be needed to meet 1996 environmental requirements.
As yet Volvo cannot give a price for its Powertronic system, which we tried on a sixwheel ELIO construction vehicle at 24-tonnes gross, but it is expected to be more expensive and, due to the torque converter, is heavier.
However, it will be appreciated by site vehicle operators as drive is continuous, even during gearchanges, improving lugging power and reducing the risk of becoming bogged down. It too has economy and power modes.