The new Scania gearbox is a heavy-duty hero
5 MAY 2023
Scania’s new Heavy Planetary Gearbox equips the Scania Super engine for the toughest mining and off-road environments, combining higher torque management, lower fuel consumption and longer service life. Two of the development teams take us behind the scenes.
The ground-breaking new heavy-duty gearbox for the Scania Super engine is the result of a decade’s worth of blood, sweat and gears.
Three years of computer simulations even before the first prototype. Thousands of hours at the Scania test track. Months of tough field tests in daily mining operations. Weeks spent analysing performance data. And scores of hardware and software iterations in response to customer feedback.
But it was all worth it. The new Scania Heavy Planetary gearbox is powerful enough for the most demanding construction, heavy haulage, agriculture, heavy forestry and mining jobs, yet lighter and smaller than the previous gearbox generation.
Better gearshifting, higher torque and fuel savings
The many impressive new features include stronger, wider planetary gears to manage even higher torque, eight reverse gears for quicker reversing, low revs at cruising speed with better startability, and an input shaft brake that boosts gearshifting performance.
All of that plus up to one percent better fuel efficiency through reduced losses; good news for total operating costs and the climate.
“The gearbox has been developed to integrate seamlessly with the Scania Super engine, for the most efficient powertrain possible,” says Tomas Selling, a software engineer who was there when it all began in 2013.
Daily discussions, gatekeepers and new insights
The gearbox goes into serial production in late 2023. For Tomas and hardware engineer colleague Daniel Häggström, the end of a long but exciting project is in sight.
“There were many iterations, and each one takes a long time,” says Daniel. “It takes 30 weeks to get prototypes done, then we do the actual testing, then we make changes before the next generation of prototypes.”
In the first few years, the hardware and software teams sat side by side. The hardware group were gatekeepers for the feasibility of software colleagues’ proposals, while the software team’s vehicle background saw them share insights into how the gearbox system would be integrated with the truck.
“We had daily discussions with each other,” explains Tomas. “There was a lot of just trying to understand one another, asking things like why it’s so important for the hardware to have a shift brake at such a torque level.”
“The gearbox hardware and software really define how you experience the truck,” continues Daniel.
“They allow the engine to operate efficiently and powerfully. And gearshifting is vital for the vehicle’s driving comfort. It’s expensive to replace if it breaks down so you need to make sure it holds up for a long time. We had to get it right as this will set the standard for the years ahead.”
Ready for the heaviest tasks
Its most rigorous and extensive field testing took place in a mine in northern Sweden. And it was the mine operators’ challenging feedback that helped the team to surpass themselves.
“There’s nothing as tough as mining operations, so if it copes with those it can cope with anything,” says Tomas.
“There are steep hills, lots of reversing manoeuvres, and lots of twists and turns on rough, loose road surfaces. If you are driving up very steep hills and the gearshifting takes too long, the truck ends up standing still.”
A product to perform year after year
“There were some stressful moments but Scania’s test drivers have heard from the main testing customer that they are very happy with the product.
“I do think we’ve ended up with the best driveline in the world for heavy vehicles,” says Daniel, with quiet pride.
“Now we have a product that will perform under the toughest working conditions for year after year,” adds Tomas.
It looks like Scania just moved up another gear…
The key gearbox specifications
| G25CH(R)1 | G33CH(R)1 |
Gears, forward / reverse | 14 / 4 (optional: 8) | |
Gear ratio, forward | 20.81:1 to 0.78:1 | |
Gear ratio, reverse | 16.23:1 to 7.61:1 (optional: 2.75:1) | |
Max input torque [Nm] | 2500 | 3300 |
Max input torque in combination with RBP900 [Nm] | 2300 | 3000 |
Weight, without retarder [kg] | 270 | 285 |
Max retarder torque [Nm] | 4700 | |
