Both in terms of hardware and software perspective, Endurant is a completely clean sheet AMT design. Eaton here in Australia have been working with the 12 speed transmission here in Australia, where it is already being sold in the Kenworth range as the Paccar AMT. The XD is the next evolution from the current offering to a heavier transmission with more speeds to take its capabilities up into the heaviest tasks in Australia.
The Endurant marks a step change for Eaton and takes the transmission to another level of functionality. The box uses all helical gearing, the splitter has moved from the back box into the front box. There are now even ratio steps across the transmission and the system uses a 43mm single plate clutch.
“There’s planet and sun gear range sections, so it’s really a totally different beast from the Roadranger product,” says Graeme Weston, Eaton Vehicle Group Australia Leader. “Also, from a software point of view, there will be more flexibility in tuning for things like running along flat ground and tuning the shift point around that. There is also the flexibility to bring in the performance aspects, when the truck is climbing grades.
“There is a lot more fuzzy logic involved. We have a lot of really good feedback from the twelve-speed in the Kenworth product here in Australia, in terms of the flexibility. We spent a lot of time on the calibration and when it went out into the market, we got some really good feedback, but it really has been left alone. we have just had a few small tweaks around the edges.
“Particularly, when we are talking about down speeding and we are getting into the faster axle ratios, around 3.07 and 3.58, where you do need economical kinds of shift points along four per cent undulating roads. Then, when you get onto an eight per cent grade, it needs to have a lot higher rpm down shift points and upshift points.”
Once the truck is over the hill the inbuilt gradient sensor will reset the shift points as the truck heads off down the grade. Some of this flexibility has been available on the Ultrashift Plus AMT, but the limitations around the finer points of transmission tuning were not available. However, they will be on the much more sophisticated Endurant XD, as it comes on stream.
The technical changes mean that the initial calibration will be a more difficult process for the Eaton team, but once calibrated, it will better able to suit a wider range of working environments. There is more inbuilt flexibility within the system to adapt to situations.
“I’m just really excited about the Endurant XD, the 12 speed has proven to be really reliable,” says Graeme. “Just things like having the flexibility around the start gear. We are really excited about getting it out on the road, to put it though its paces.
“Like we did with Ultrashift Plus, we are starting off with B-double application and up to 85 or 90 tonnes GCM. Then we will start to go up from there. On of the things we are focussing on, and because it needs to be integrated more with the chassis, we are starting off with models which are ‘digital’. So, the Kenworth T410 and T610 will be first and then we will have to work on the legacy analog chassis afterwards.
“At the moment, the heaviest we have got with Ultrashift Plus is about 330 tonnes and we are expecting to get the Endurant XD up there as well.”
The Endurant development and launch is the main focus of the Eaton team in 2021. The hope would be that the new transmission will perform well enough to tempt the more traditionally minded truck buyers to move away from the Roadranger and into the Endurant XD.
The chances are that the Endurant XD will persuade some of the hold-outs to transition across to AMT, but the Kenworth is gradually becoming one of the few brands to offer manual gearboxes in large numbers.