Climbing up into the cabin of the larger Hino prime mover, the SS 2848, is a different proposition to the smaller rigid FY model. The 700 cabin with the 13 litre engine sits 120mm higher than the model fitted with the nine litre. They are both 700 Series models but they really do look and feel different.
The SS model with the ZF Traxon AMT has an extra control stalk to the left of the steering column. The dial on the dash can be twisted when stationary from neutral to drive to slow manoeuvring drive to reverse to slow manoeuvring reverse. However, the stalk is used when actually out on the road. This has a paddle to go up and down a gear and the button to toggle from auto into manual and back.
Taking off, the 16-speed AMT really comes into its own. This is a proactive gearbox which wants to work and wants to get going. The last twenty years of the ZF AMT have seen it progress from a smart functioning idea to an extremely smart mature technology. The difference is the quality of the data the controlling computer is receiving from systems all over the truck to ensure it makes the right decision in a nanosecond, when required.
The AMT has three modes, eco, standard and power. When the truck was under load the Traxon would not make an up-change after hitting 1800rpm and rarely let the revs drop into the green band.
The competition between all of the major transmission designers has been hot and the resulting product has been forged by each iteration of each box needing to get one small step ahead of the competition. The result is a choice of highly sophisticated AMTs from just about every truck brand.
For retardation the stalk on the steering column has four stages, with the engine brake increasing in two steps and then the Intarder adding a further two steps of really effective retardation. The combination of the Intarder and the Traxon AMT means it is possible to wash off all of the speed going into an intersection or a parking bay by simply pulling on full retardation and allowing the combination of the two to bring the speed back to a point were a small application of the service brakes is all that is needed to bring the combination to a halt.
A ZF Intarder on the 13-litre engine at relatively high masses has proved to be very effective part of the driveline and will considerably improve brake life.
On the larger SS prime mover with the ZF box, Hino have finally got the message and moved the transmission controllers to the dashboard, leaving enough space for the driver to be able to comfortably climb into the middle of the cabin.
At 480hp this engine has enough to handle single trailer work and runs at 1500rpm at 100km/h easily, holding on well out in undulating countryside. Surprisingly, the green band on the tachometer is marked from 800 to 1400rpm, suggesting running at highway speed is just outside of its most economical zone. A taller diff would get the revs down into the green band at 100km/h, but may compromise performance elsewhere, where it is needed.
Power was the right mode setting as the semi approached the foot of the Cunninghams Gap grade. Once the truck got into the climb the Traxon worked to make sure the engine was close to 1400rpm, clearly the home of the best torque from this engine.
When into the meat of the grade the truck was comfortable at 35km/h in 11th gear at 1400rpm and it could grind the climb out, despite the changes in grade. At other times it will allow the revs to drop well below 1300 and then take a single gear to get back to 1500rpm as it grinds up the grade.
The smartness of the AMT becomes clear when the transmission makes surprising choices which turn out to be the right ones. Sometimes it will hold a gear until the revs get over 2000, and then at other times it will grab two gears and drop it down below 1450 rpm while climbing hard. All of these moves proved to be correct, the power and torque available were more than capable of handling the task set by the transmission.
This is a Hino 13-litre engine rated at 480hp and we can’t expect it to fly up this ascent pulling a fully loaded semi. There is something about the quality of the torque an engine produces and Japanese engines rarely really impress, but it does do a commendable job, it seems to be well within its comfort zone all of the way up the Gap.
The return descent of the Gap saw the new Intarder now fitted on the Hino 700 prime movers come into its own. Dropping the AMT into manual, selecting 12th gear and pulling the lever to full retardation gives the driver a smooth descent with no need to apply the brakes and no worries about over speeding. Speed can be simply controlled by changing up and down manually.
Moving up into 13th and 14th gear the Intarder continued to hold the truck back easily. This is a top highway prime mover level of retardation, available on a Japanese prime mover.