Eaton cuts footloose

It’s hard not to compare the new Eaton Fuller UltraShift 10-speed with Eaton’s AutoShift compatriot. AutoShift, you may recall, uses electronic controls to automate gear shifts according to the engine rpms and road speed. You still have a clutch pedal on the floor, but you need it only for starting and stopping the vehicle. Otherwise, the AutoShift functions like a full-blown automatic once you’re under way.

The 10-speed UltraShift, introduced in March, uses the same basic B-ratio transmission and the same shift logic as the AutoShift 10. The difference, really, is in the clutch.

It’s still there–the company’s new DM AutoClutch, in fact, with a 15.5-inch, two-plate design and industry-standard ceramic facing material. But there’s no pedal to do the actuating. Instead, the UltraShift uses a centrifugal clutch that spins into a locked position as the engine revs increase and drops out of lock when the engine spools down. The simple ball-and-ramp affair (Eaton won’t say much more than that) 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 sporting an UltraShift 10 behind a Cat C-12. Pulling a loaded 53-foot van, we headed onto the back roads of Western Michigan. There aren’t any serious grades in this part of the country, so we settled for minor highways, little hills, and the traffic of a zillion towns and villages.

Jim and I both had used the AutoShift before and knew the basic software hadn’t changed, so we mostly wanted to see how the UltraShift and its automated clutch managed starts and stops. Answer? Very smoothly, with only the slightest lag off the line.

In theory, both the AutoShift and UltraShift will automatically skip a gear when conditions warrant, but with the 34-per-cent-plus steps of a 10-speed, that’s not going to happen too often. We didn’t see one all day.

Compared to the AutoShifts we’ve driven, this UltraShift didn’t downshift as early as we’ve seen before, and that’s for the better. Eaton’s Bill Batten, product planning manager for Roadranger marketing, confirmed that there’s been some tweaking of the parameters.

It did make one odd downshift that neither Jim nor I would have made. At about 60 mph in top gear we encountered a very slight grade 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 1,275 to 1,300 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 to us once.

Of course, you do have the option of taking shifts into your own hands. To switch to manual mode, you slip the lever–or push a button in some trucks–to “M” and then punch “up” and “down” buttons to shift. An “L” position (for “low”) 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 (the transmission’s ECM 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 a trailer hook/ drop manoeuvre, procedures that would normally demand a little fancy clutching. Neither one was a problem, but I had to re-think my footwork. Instead of slipping the clutch to move the truck gently and then alternating between clutch and brake, with UltraShift you switch feet. You advance the truck with the throttle pedal (right foot) and slow its progress with your left (the brake)–the opposite of what’s done with manual clutch. Not a big deal, but it would take getting used to.

Comparisons to the ZF Meritor FreedomLine transmission are inevitable here, it being the UltraShift’s direct competitor. There some key differences: FreedomLine is available in 12- and 16-speed direct and overdrive versions, with torque capacities to 1,850 pounds-feet. The UltraShift line has a six-speed and a 10-speed, with the 10 available in four torque capacities from 1,050 to 1,650 pounds-feet (Batten says 13- and/or 18-speed versions of the UltraShift will come, but he wouldn’t suggest a date). Another consideration is weight: FreedomLine weighs less than the UltraShift, by 106 pounds in the 12-speed version and 77 pounds in the 16-speed, according to spec sheets.

So, UltraShift or AutoShift? They’re both 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 UltraShift a fleet transmission? 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 favour 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.

From a pure “driving” esthetic, however, there’s the issue of feeling like you’re “along for the ride,” as my colleague Mr. Park put it after a day with the UltraShift. A guy with a couple of million miles of manual shifting, most of them with a 13-speed, Jim felt a disconnect between himself and the truck when all there is to do is hang onto the steering wheel.

A natural reaction, I guess, though I didn’t feel the same way. I admit I wasn’t at the wheel long before I moved the shifter out of “D” and took charge myself for a while. I didn’t miss the clutch pedal or the joy of finding synchronous, but I wanted control. A couple of times I thought that I knew better than the transmission where engine rpm ought to be.

The fact that the transmission can be used that way–as a full-bore automatic or a semi-manual-is both its strength and its weakness. In a truck that’s spec’d right and used well, the UltraShift will protect the driveline while allowing pretty full manual control when necessary. But used poorly in manual mode, a driver could waste fuel just as easily as he could with a 13-speed shifter in his right paw. True enough, as Jim points out, a very good and disciplined driver might be able to leave the UltraShift in “M” and match or even better the fuel mileage achieved by the transmission’s own shift logic.

For most folks, though, the “D” lever position will likely do just fine. And they’ll have both hands on the wheel.