ROAD TEST: EATON'S ULTRASHIFT TRANSMISSION
Eaton has taken the AutoShift idea one important step further with the new UltraShift, though they both use the same shift logic. It’s the same basic transmission -- a 10-speed based on Eaton’s tried-and-true B-ratio mechanical box -- but the clutch pedal has disappeared. The new UltraShift is available with four torque capacities from 1050 to 1650 lb ft.
With the AutoShift, drivers use the clutch pedal to start and stop the truck, but in between it’s an automatic. The new UltraShift automates operation of the clutch
altogether. It’s still there -- the new ‘DM AutoClutch’ with a 15.5-inch, two-plate design and industry-standard ceramic facing material -- but there’s no pedal to do
the actuating. Instead, it’s a centrifugal clutch that spins into locked position as the engine revs increase, and drops out of lock when the engine spools down. It’s a
simple ball-and-ramp affair (Eaton won’t say much more than that), and takes up no more space than an ordinary clutch within the standard bell housing. It incorporates an inertia brake that speeds automated upshifts and serves as a clutch brake. The engine brake still helps with downshifts.
And how does it work? Colleague Jim Park and I recently collected a Kenworth T2000 Eaton engineering tractor pulling a loaded 53-ft van and headed onto the back roads of western Michigan. It sported an UltraShift 10 behind a Cat C12.
There weren’t any serious grades around so we settled for minor highways, little hills, and the traffic of a zillion towns and villages.
We had both used the AutoShift before, and knew the basic software hadn’t changed, so we mostly wanted to see how it managed starts and stops. Answer?
Very smoothly, with only the slightest lag off the line.
It did one odd downshift that neither of us would have made. At about 60 mph in top gear we encountered a very slight grade which the Cat would have pulled easily, but the transmission didn’t agree and launched a one-cog drop. In fact, the truck’s gearing gave us 60 mph at only 1275-1300 rpm (I calculate a rear-axle ratio of 3.36). So maybe it’s not surprising that the shift logic would order a
change with revs falling from that low point on the tach, but it only happened once.
Compared to AutoShifts we’ve driven in the past, this UltraShift was much better in that respect. It didn’t downshift as early as we’ve seen before, and Eaton’s Bill
Batten, product planning manager for Roadranger marketing, confirmed that there’s been some tweaking of the parameters. That’s all for the better.
In theory, both the AutoShift and UltraShift will automatically skip a gear when conditions warrant, but with the 34%-plus steps of a 10-speed, that’s not going to
happen too often. We didn’t see one all day.
When you decide to use the transmission in manual mode, you slip the lever -- or push a button in some trucks -- into ‘M’ and then use up and down buttons to make your shifts when you like. There’s also an ‘L’ position (for ‘Low’) that lets you hold a given gear or make early downshifts to take advantage of an engine brake. It can also be used to start off in first gear (otherwise it usually chooses second) and it’ll stay in low until you move the lever to drive mode. All of that is just like the AutoShift.
We tried finessing the truck into a loading dock and managing the trailer hook/drop procedure, which normally demand a little fancy clutch work. It wasn’t a problem, but it did demand re-thinking the process. Rather than slipping the clutch to move the truck gently, and alternating between clutch and brake, with UltraShift you switch feet. You advance the truck with the throttle and slow its progress with your left foot on the brake -- not a big deal, but it would take getting used to.
Comparisons to the ZF Meritor FreedomLine transmission are inevitable here, that being the UltraShift’s direct competitor. The FreedomLine is available in 12- and 16-speed direct and overdrive versions, with torque capacities to 1850 lb ft. It weighs a bit less than the UltraShift, by 106 lb in the 12-speed and 77 lb in the 16-speed, according to spec sheets. Batten said 13- and/or 18-speed versions of
the UltraShift will come, but he wouldn’t pin down a date.
The UltraShift 10-speed is currently in ‘limited quantity release’, with 1000 examples to be sold over the next 12 months. Full production should start about this time next year, we’re told.
So, UltraShift or AutoShift? They’re both very capable, but a lot of driveline damage can be done by a rookie or a driver who’s simply careless with the clutch, so there’s a vote for the new box on the block.
Is it a fleet transmission only? Not at all. With a husband-and-wife owner-op team, for example, where the woman is new at the game -- and there are thousands of happy couples rolling across North America in exactly this mode -- the UltraShift will find favor as the AutoShift already has. As she rolls it into a truckstop, her downshifts will sound just as crisp as the ones he’s been doing manually every day for 30 years or whatever. And he won’t be worried about metal shavings in the sump.
In any case, it seems clear that transmission automation will gain progressively more fans as time goes on. Aside from the added expense, there’s just no reason why not.