Kenworth T880: Smoother, Finer T8

May 30, 2013

It’s not every day that a manufacturer brings out a new Class 8 truck, especially one that will cut into sales of one of its most popular models. But that’s what Kenworth Truck has done with its T880, the undeclared (for now) successor to the venerable and versatile T800. The 880 is designed to fill the same roles, though it will ease into them after it goes into production this summer, and the T800 will continue as an offering as long as volume justifies it.

The stage for the T880’s introduction was the annual Mid-America Trucking Show in Louisville, Ky., during which Kenworth had a couple of copies for us press people to drive. One was this dump truck and the other a regional-haul tractor, and I found that the 880 is smoother, more refined, nicer-looking and roomier than the current model. The long-running (since 1986) and highly regarded “T8” shared some basic components with the “anteater” T600 of 1985, and so it is with the T880 and the modern T680 highway tractor that came out last year. Kenworth product specialists say the 880 uses the same cab and interior components, as well as basic frame design and other refinements, though of course heavier frame pieces and running gear are among items on the options list. 

Kenworth T880 Test Set

Truck: 2013 Kenworth T880 daycab vocational truck, BBC 122.5 in., w/ pintle hitch, air gladhands, and 7-way electrical connector for pup trailer (not used in this drive)
Engine: 12.9-liter (788-cu.-in.) Paccar MX-13; 500 hp @ 1,500 rpm; 1,850 lb.-ft. @ 1,100 rpm; w/ engine brake
Clutch: 15.5-in. Eaton Solo Advantage
Transmission: Eaton Fuller RTLO18918B, 18-speed overdrive w/ Chelsea PTO
Steer axle: Dana E-1462I, 14,600-lb. capacity w/ TRW-Ross TAS85 hydraulic power, on taperleafs
Lift axle: Watson-Chalin SSR WCAL, 13,500-lb. capacity
Rear tandem: Dana D46-170H w/ 4.10 gearing, 46,000-lb. capacity, on Chalmers 854-46-L-HS mechanical suspension
Wheelbase: 213 in.
Tires, wheels: 385/65R22.5 Michelin XZY3 front, 11R22.5 XDEMS rear, on Alcoa aluminum discs
Brakes: Bendix air discs w/ Bendix 6-channel ABS
Fuel capacity: 110 gal.
Body: OSW Equipment 10/12-yard steel dump

Obvious changes to folks who know the old model is the T880’s wider cabin and its more streamlined nose. The cabin is about 8 inches wider than the “narrow” cab used in many of the T series and the traditionally styled W900 series highway tractor, as well as the W900S vocational truck (which looks like a T800 but has a forward-set steer axle). The 880’s one-piece curving windshield is huge, and its glass is said to be rugged enough to shrug off most stone hits. The 680’s cab was validated for the rigors of vocational use so needs no modifications, said Alan Fennimore, KW’s vocational product manager.

The hood retains a steep slope but is 2.5 inches shorter than the 680’s, and is made in five sections, including detachable fenders, so they can be replaced piecemeal in the event of damage that’s more common in vocational trucks. Optional fender extensions will cover wide-base flotation tires used on high-capacity steer axles of up to 22,000 pounds. The grille is metal with a stainless steel surround to protect the radiator and stay good-looking.

Headlamps are complex-projector beams whose halogen bulbs are cheap and easily replaceable. The lenses are smartly blended into the fenders instead of protruding like squinty frog’s eyes, as with the T8’s quad rectangular halogen sealed beams. 

Those new headlamps are effective at night, said Brian Lindgren, research and development manager who rode shotgun in the dump truck. I had to take his word for it because we did our driving on a bright, sunny and mild morning—weather to be thankful for in the iffy month of March in this region. Although I also drove the 880 tractor that was hitched to a heavily loaded flatbed trailer, I concentrated on the dumper for this story.

The dumper toted a mound of aggregates that pushed gross weight to about 70,000 pounds. That’s realistic for a four-axle configuration, including one liftable, steerable pusher, that’s common in a number of axle-weight states. But its smaller, single wheel and tire at each axle end is not what’s used in central or eastern states, and that’s because the truck was built for use in the Pacific Northwest, where state bridge-formula laws are rather liberal. This truck had a pintle hitch, gladhands for air brakes, and a seven-way electrical connector at the rear to pull a long-tongued pup trailer. This would add 35,000 pounds, for a gross combined weight rating of 105,000, Lindgren said. 

That heavy GCW is one reason the truck had the top-rated Paccar MX-13, with 500 horsepower and 1,850 lb.-ft. that ably got this wagon rolling. The 12.9-liter MX is standard in the 880, as it is in most of KW’s Class 8 models, while Cummins’ ISX diesels are optional. The dumper also had an Eaton Fuller 18-speed Roadranger, where a straight-only truck might’ve had an 8LL with a low-low range box. As it was, I never needed Low gear in the 18, which had wide ratio coverage with overdrive top ratios, running through stump-pulling 4.10 gearing in the tandem’s diffs. 

What I did need was some familiarization time with the transmission, both the 18 in the dumper and a 13-speed in the tractor, because their gearshift levers seemed mounted in molasses and they sometimes stuck in gear. I learned that it happened less if I switched their range boxes into Low before trying to pull them into Neutral prior to a low-speed downshift. But the tranny in the dumper still occasionally stuck in 8th-direct (the transmission’s 17th ratio), even at higher road speeds, until I banged it with the heel of my hand. The trannies’ precisely machined and tightly meshing gears probably needed more miles to wear in. 

Steering was annoyingly mushy in this dumper, with TRW-Ross power gear.  Yes, the truck had large 385-series front tires that wander a bit, and a pusher axle tends to produce a disconcertingly buoyant sensation. And yes, a regular driver will get used to this and find, as I did after maybe 25 miles, that a steady hand on the wheel compensates. Choosing the optional Sheppard power steering, which was in the tractor, might provide a more exact feel, though even that seemed vague to me. Commendably, wheel cut was sharp and maneuverability was tops, and both truck and tractor were easy to put through sharp turns.

One other nitpick: The dumper had a large, multiuse color screen in the dash, but bright sunlight streaming through the daycab’s rear and side windows obliterated what was on it. The screen supports a Nav-Plus navigation system, among other things, and it would be a better feature if the screen were legible in direct sunlight, as some in the auto and computer industries are.

Ride quality was good, though there was some jouncing on the sometimes bowed concrete of Interstate 264 south and west of Louisville, and on I-64 in southern Indiana. I cruised at 65 mph or so, where engine revs were at about 1,500—correct for a vocational application and right where 500 horses are available—and the cab’s interior remained quiet. We had left Peterson Kenworth, where the 880s were staged, and were headed across the Ohio River to a place called Floyds Knobs (a hilly area named after a 19th century politician). Here Keith Redden, owner of K. Redden Trucking, let us use his yard as a turnaround and place to pose the dumper for photos. He runs 23 T8s and the latest ones have the MX diesel, about which he has only good things to say. He was curious about this 880 dumper because he had ordered one almost sight-unseen.

Three of his drivers drifted in and gathered to eyeball the new model. They seemed to like the 2.1-meter-wide cab (82.7 inches), which adds lateral spaciousness even if it’s not absolutely needed in dumpers and concrete mixers. However, Lingren noted, it’s as long as a T800’s cabin with the Extended Cab option that costs $2,000 to $2,500. That happens to be the price premium for a T880 over a T800, and the 880’s standard with increased leg and belly room—an equitable deal. 

The new instrument panel is more graceful, with a single, slightly curved panel in place of the T8’s two flat panels. Rocker switches are still used, and gauges remain a simple, legible, white-on-black design similar to those on the T800. So drivers should have no trouble adjusting to the new model’s interior.  

They won’t have to if their bosses continue to buy the T800, as will many operators who are satisfied with the still-excellent T8 and suspicious of any new model. Eventually, though, this something-new T880 will become tried-and-true, and will replace the old truck. That’s progress.