Getting Retardation Right for Hino

getting retardation right for Hino

Working in rural areas is one area where Japanese brands specialise and, in getting retardation right for Hino, the 700 Series has found a home in quite a few farming industry associated tasks. Working in this segment is not a high mileage task, but it is tough on the trucks. They are rarely turned over after just a few years on the job, they are expected to put in good service over many years, and are only replaced when thoroughly worn out.

One of the plusses of utilising the ZF Traxon AMT in the driveline is the opportunity to include ZF’s Intarder in that driveline as well. This takes retardation on a Japanese heavy duty truck to a whole new level. The first two pulls on the retardation steering wheel stalk, bring in the exhaust and the compression braking from the engine, but go to the third position and the Intarder kicks in.

The performance of this transmission retarder has always been impressive, as it has been fitted on a number of European trucks over the years. This is not just engine braking, this is a beneficial tool to minimise unnecessary brake wear. 

Driving along the highway and spotting a suitable parking bay does not need a complex mix of braking and downshifting from the driver, it’s just a single movement to perform a seamless task. Pull on the stalk to activate retardation and speed drops immediately. The retarder is holding back the driveline and communicates what’s going on to the AMT.

As a result, the AMT starts downshifting quickly. Revs go up and so the engine braking and transmission retardation becomes even more effective. The truck slows without any driver input, the truck drops to the right speed to enter the parking bay and continues to slow. When the truck is about to park, the driver simply presses on the brake pedal to bring the truck to a complete halt.

getting retardation right for Hino

This kind of integration shows us just what can be achieved by this relatively new technology in basic workhorse trucks designed for rural areas. The truck buyers in country areas have long held out against any move away from the most basic truck designs, but the latest smarter technology now coming on-stream should be a no-brainer. It works well, is safe and only uses the sophistication in the system, which has to be included to ensure the modern engine meets emission rules. 

The use of this system can be seamless from the driver’s point of view, as there is a switch which blends all of the retardation together. Simply pressing the foot brake brings in a cascade of stopping power. The first few per cent activate the exhaust brake, the next stage sets the compression brake off, while the third introduces the Intarder to the equation. Further pressure brings in the driver’s last resort, the service brakes.

For drivers used to the much simpler, but sharper, brakes in the past, this may be a little disconcerting at first. The foot seems to travel some way before the sharp service braking comes into play. For this driver, after the first couple of brake applications, it was easy to adapt to the braking performance and maximise retardation, when needed, while minimising brake shoe wear. 

getting retardation right for Hino

Another intervention from the Traxon transmission is also in evidence in the background as it goes up and down the gears. The system uses the engine compression brake to get the revs just right as it makes the gear change. This results in a short sharp burst of the engine brake burble as the revs are fine tuned. This sound isn’t intrusive or worrying in any way, but drivers handling a modern AMT for the first time may find it a little confusing.

There is a switch to change the AMT behaviour into crawler mode, enabling slow manoeuvring when coupling and uncoupling trailers, or getting in an out out of awkward areas. Another vital component for any rural based truck is the inclusion of diff locks and cross locks to help the truck and its load get out of sticky situations. 

Getting Suspension Right for Hino

One of the heroes of the drive around the back roads of country Queensland, down through Texas and across the border into New South Wales, was the truck suspension. These roads are far from the best and among the worst in this area but the hidden dips and bumps were not too dangerous for this driver. 

The combination of semi-elliptical steel suspension on the front and the well-known Hendrickson HAS 460 air suspension, dealt with the conditions with relative ease. There were no clashes with the cab roof and the driver’s seat did not bottom out at any point. This is quite an achievement on these roads when travelling over 80km/h. 

This is a tried and true set up, using well known components, but the performance shows a lot of thought has gone into getting the balance just right on the way the suspension has been set up to cope with this kind of transport task. Often it is not just about fitting the right components, but getting them to work in harmony.

Since its introduction over 15 years ago, the Hino 700 has been improved to meet the expectations of the market. The first set of changes saw a vast improvement in steering and suspension performance. Later, the introduction of the ZF AS Tronic AMT brought the truck into the 21st century. Upgrading this transmission to the new ZF Traxon sees the model keeping up with the trends in the market which this kind of truck requires.

getting retardation right for Hino