Addition of Eaton Ultrashift automated manual transmission as an option for Cat Trucks is proving to be a smart move
By Gary Worrall | June 1, 2012
The addition of the Eaton Ultrashift automated manual transmission (AMT) as an option for Cat Trucks is proving to be a smart move, with operators snapping up the new offering.
Cat Trucks General Manager of Sales and Marketing Jeff Tyzack says the Ultrashift option is a retrofit in both the CT610 and CT 630 models, with the control panel replacing the floor mounted gearshift of the manual versions.
The conversion is handled by Cat Trucks at its head office in Tullamarine, Victoria by the in-house technical team, ensuring full compatibility with the rest of the truck’s systems.
Tyzack says more than 20 units have been delivered in 2012 with the Ultrashift option, with operator feedback showing it is likely to increase in popularity.
In a recent test drive of both models, driving between the western Sydney Westrac dealership at Holroyd and the township of Katoomba at the top of the Blue Mountains, the Ultrashift proved to be effective and smooth.
The CT610 is a day-cab rigid tipper, tipping the scales at 21.6 tonnes, while the CT630, also a day-cab, is rigged for duty as a tipper and dog with a loaded weight of 44.46 tonnes.
The first thing you see in the cab – or do not see in reality – is the extra space that removing the traditional gear stick creates. Even with the additional control panels for the transmission and the tipper controls between the seats, the cab does not feel crowded.
Attention to detail is a hallmark of the Cat Trucks, with the finished product displaying high levels of workmanship inside and out, which is brought to the fore by the fitment of the Eaton AMT.
By removing the mechanical linkage between the cabin and the driveline, in-cab noise and vibration is markedly reduced, allowing the driver to relax into the task, while the flat floor is completely sealed from the outside world, eliminating dust and draughts.
For tipping operations, this means the cab area remains cleaner, while the large, electronically controlled and heated Euro-style mirrors allow the windows to remain closed without interfering with the driver’s rear vision, also preventing dust and dirt from settling in the cab.
The door seals are excellent. With the windows closed cruising at 100km/h on the freeway out of Sydney, there was no whistling of the slip stream around exposed edges. The dash remained tight, with no squeaks or rattles despite the variable road surface.
As part of the Ultrashift fitment, Eaton includes a hill holder function via the ABS brakes so the brakes remain applied for three seconds after the pedal is released.
This allows the driver to smoothly bring up the power for perfect take-offs, even on steep hills when heavily laden.
This is one of the real benefits of the AMT. While top-shelf drivers will always feel comfortable with three pedal transmissions, the clutchless manual allows more drivers to reach a level of competency and consistency that makes fleet operations profitable.
The Ultrashift proved to be fast and accurate with the shifts, offering a range of functions including auto mode, where the computer makes all the decisions.
It has manual mode, which allows the driver to decide when to make changes, and a low range that locks the gearbox in the bottom half of the range. It is ideal for steep descents and other situations where low gear is appropriate.
There is also an electronic lock-out to prevent driveline damage if the engine revs and road speed are not correct, such as shifting into 12th at 90km/h. The driver receives a warning beep to signal the shift has been denied and to alter either road or engine speed.
Another clever function is the ability to select low range while cruising at high speed. The computers will then begin slowing the truck and progressively shifting down gears until it achieves low range, at which point the driver can then select a specific gear, such as 7th, for the application.
This assists the driver if they are caught out by a change in road conditions, without needing to manually downshift to the desired gear, with the computer able to manage the gearshifts so that it never misses a gear.
In the case of the Cat Trucks application, the engine and transmission are almost perfectly mated.
Despite Eaton not having time to program dedicated shift routines for the current model, the torque curve of the C13 and C15 engines combine with the available gear ratios to offer the driver a flexible driveline, even when fully laden.
With plenty of road works on the test route, both trucks proved to have good in-gear acceleration, while the final drive ratio of 3.9:1 ensured 100km/h cruising did not result in excessive fuel burn.
Tyzack says Cat is working with Eaton for the forthcoming models, due here later this year, to not just offer an economy mode, but also a power mode for even better acceleration.
The current shift program, designed for other engine applications, holds the revs outside the torque curve so that rather than improving acceleration the end result is simply higher fuel burn.
While the Ultrashift shone with its smooth gear shifting on the roads up to Katoomba, the other advantage was in stop-start traffic where the computer-controlled clutch eliminated the need for the driver to intervene.
With a heavily laden tipper, or tipper and dog, this means the driver is doing significantly less physical work each day. It reduces fatigue and allows them to concentrate on traffic and other driving hazards, making the whole task safer.
Tyzack says while Cat will continue to offer the traditional three pedal transmissions in future models, he believes the Ultrashift option will only become more popular as operators discover its effectiveness across a range of applications.
