Driving a 5900i: Smooth Cruisin' With Little Work

Sept. 28, 2010


The hefty 5900i dumper has "rental-truck" looks and is as nice a drive as you'll find with as much power as you'll need.
The 7600, International's lower-priced severe service series,  has an automotive look and feel, but can handle some heavy work.
The instrument panel in our 5900i test truck has a big-rig layout. The AutoShift selector is at the lower-right, next to the cupholders, and there's still a clutch pedal on the floor.
Cat C-15 has a modest 375 hp/1,450 lbs.-ft., but AutoShift makes the most of it.
It's three big steps for the kind of man (or woman) lucky enough to pilot the comfortable and capable 5900i.

Test Set

Truck: International 5900i, conventional cab, BBC 120 inches, w/C-channel frame reinforcement

Engine: Caterpillar C-15, 375 hp @ 2,100/1,450 lbs.-ft. @ 1,200

Clutch: Eaton Fuller EP1552 Easy Pedal Plus 2-plate

Transmission: Eaton Fuller RTO16910AS2 AutoShift 10-speed

Front axle: 20,000-lb. Meritor FL941 on 20,000-lb. International 2-stage multi-leaf

Rear axles: 46,000-lb. Meritor RT-46-164P with driver-controlled diff locks & 4.30 ratio, on 46,000-lb. Hendrickson HN462 walking beam

Wheelbase: 248 inches

Body: 14-yard J&J aluminum

In this story:

It was like at first sight. This International 5900i dumper was one of two dozen 5000, 7000, 8000 and 9000 series trucks and tractors available for tryout at a recent Ride 'N Drive event, and I drove as many as I could. Each was a pleasure in its own way, but this one caught my attention because of its still-unusual transmission: Eaton's slick-shifting AutoShift.

The big blue dump truck was one of several that International had set up for this event with automated or automatic gearboxes. Most customers had heard of the automated AutoShift and a competitor, the ZF Meritor FreedomLine, but few had driven one. About 300 customers and their dealer hosts got their chance to sample the driving ease offered by these components, along with Allison automatics, at this event, in mid-February near Phoenix.

Medium- and heavy-duty vehicles were divided into on-highway and on/off-road groups, and I spent most of my time with the construction-oriented trucks. International builds severe-service trucks in two ranges: 5000i, the premium series with a large aluminum cab, deep frame rails, and 15-liter Caterpillar and Cummins engines; and the newer 7000, a beefed-up version of the medium-duty, high-performance 4000, with a large steel cab and 7- and 8-liter International diesels or 10-, 11- and 12-liter Cat and Cummins power.

The 5000i offers as much as 535 horsepower, a stronger frame, and distinctive big-truck styling and feel. The lower-priced 7000 can be set up for rather heavy-duty service, though top horsepower is 430 and its cab possesses a more automotive feel. Extended and crewcab variants, plus front-driving axles, are now available as factory options in the 7000.

International's offering of two complete series allows it to serve a wide range of customers. Yet it is striving to cut the number of suppliers it deals with and reduce available options to users. An International can be set up to deal with any hauling task you might have, but it may or may not be spec'd exactly as you'd want it.

AutoShift's manual clutch

About two and a half years ago, I wrote up the FreedomLine, which is built by ZF in Germany and altered for use here. It's a two-pedal system with an automated clutch. But I had not encountered a construction truck with an Eaton AutoShift, and now here it was. This product has a manual clutch, so the truck has three pedals, like a manual transmission.

Eaton says it has sold about 10,000 of the automated mechanical transmissions since its introduction in 1996, but most have gone into road tractors. Marketers have not pushed it into severe service, but International has okayed it for dump trucks (but not mixers). AutoShift is now into its second generation, with refined electronics that effect smoother gear changes and suffer fewer curious glitches that plagued early models.

The AutoShift combines the smarts of an automatic with the solid feel of a manual gearbox, which is exactly what it is. Electronic controls and servo mechanisms are applied to a 10-speed Roadranger to make it shift for itself.

As I said, the AutoShift still has a manual clutch. You depress the clutch pedal to start the engine (at first I forgot to do this and the engine wouldn't crank), then engage the clutch to move away from a stop. You also punch the pedal as you roll to a stop and sit with the engine idling.

Otherwise, while underway, you leave the pedal alone, and the clutch stays engaged as the AutoShift float-shifts up and down the ratio ladder (by contrast, the FreedomLine employs its clutch for every gear change).

AutoShift's electronic brain talks to the controls on the engine, which revs and slows to mesh the gears during shifts. The engine needs a Jake Brake to slow quickly for fast upshifts and, of course, the Cat C-15 under the hood of this 5900i had one.

When its properly programmed, the transmission chooses the right gear for every situation and grabs it quickly and smoothly. It works like your best driver all the time; it doesn't get tired toward the end of a long day, so it doesn't grind gears, miss shifts or pop the clutch.

Drivin' in the dirt

On this little trip, I easily wheeled the partially loaded International dumper along trails graded into the desert dirt on the premises of the Phoenix International Raceway. An LED readout told me the transmission usually started in 4th on the level, and up-or down-shifted as I mashed the accelerator or touched the brake pedal to take a turn or go into a hollow.

Twice I stopped on a steep incline to see if the Cat would stall as I engaged the clutch. Nope—it picked up the load, even in a gear higher than I would've chosen, and the tranny grabbed the next gear as soon as it could, rather than waiting to crest the slope, as I would've done. There are no low-low ratios, but smooth operation more than made up for them.

I could also control its shifting by punching the buttons with up or down arrows, causing an up- or downshift if the transmission's brains deemed it proper. Or I could hold the tranny in a chosen gear.

However, it is possible for the AutoShift to fall out of tune and shift erratically. Electrical problems elsewhere in the truck can migrate into the transmission's electronics, interfering with operation. Eaton says such problems occur far less frequently with the second generation AutoShifts, and when they do, dealer technicians are supposed to have the know-how to reprogram the black box and fix other things. It also helps if you have a mechanic who knows how to trace circuitry to find and fix shorts.

Help on call

Eaton has a toll-free number (800-426-HELP) where technicians are waiting with instructions for users or dealers, and Roadranger technicians are in the field and will stop by if need be. In any case, the smart way to get something like this into a fleet is to make sure your dealer is ready to support it, and will train you and your service people. Then buy a few, put them in service and sort them out. If they work, you can buy more.

Why bother? Because you can save money in maintenance, as clutches, U-joints and other driveline pieces take less beating and therefore last longer. Eaton says AutoShifts can also save several percent in fuel; that's not been a high priority for operators of construction trucks, but the recent surge in diesel prices may have you changing your thinking.

Obviously, the AutoShift and similar products are much easier to drive than manual transmissions, and that means relatively inexperienced people can be put behind the wheel. Just make sure they understand how to use that clutch pedal, and they do not try to hold the truck on a grade by feathering the accelerator, as that's the same as riding the clutch. Even most experienced drivers like the AutoShift, Eaton says, because they simply work less hard.

Some folks think the future of big trucks is with automated or automatic transmissions, and I'm inclined to agree every time I drive one. But automation costs money. At International, an AutoShift with this torque capacity sells for about $3,900 over the base 10-speed manual. That's well under half the price of an Allison HD. A two-pedal FreedomLine costs about $5,400, but is available only in the 9000 series highway trucks and tractors. Volume tends to bring down prices, and that might turn a relatively few sales into a wholesale trend.