The fully automatic transmission on the High Horsepower 300 Series light duty truck is now capable of steep descents without touching the brakes
When we test drove the new 300 Series High Horsepower light duty Hino last year, we had a significant criticism amongst the praise for the little unit.
We discovered in driving down the very steep Mount Ousley near Wollongong south of Sydney, that we had to keep touching the foot brakes.
The fully automatic Allison transmission wouldn’t let us select a low enough gear to hold the truck on its own at the legally required 40 km/h.
Third gear was the lowest the transmission would let us manually select. We needed second.
We weren’t concerned about the brakes overheating and fading. Hino says they were well within their capacity.
Instead we were worried about unwanted attention from any highway patrol officers that might have seen the brake lights coming on way more often than legally allowed down the infamous stretch.
We now have some good news for anyone who might need to traverse similar terrain in this little truck.
Back in the factory Hino has now reprogrammed the transmission control unit in trucks bound for Australia so that the vehicle can be manually put into second gear.
So down Mt Ousley we recently went again, this time after manually selecting second gear and activating the exhaust brake.
This worked a treat. If we were actually going a little too slowly – and worried about big bangers looming up behind us – I would take off the exhaust brake until we were back up to 40 km/h.
Then if we threatened to go over the speed limit or we were getting perilously close to the redline at 2700rpm, it was back on with the exhaust brake.
Using this method I didn’t have to touch the foot brakes once.
Using the alternative method of touching the throttle to speed up a little bit was no good, because that would kick the gearbox up into third, and cause the truck to “run away” again.
For more on how to get the best from fully automatic transmissions, check out the June issue of ATN.