A forward-set steer axle is usually a means of stretching a truck’s wheelbase to meet weight-distribution laws in so-called bridge states, and that’s the reason for Kenworth’s new vocational T880S. But its brawny, flat-faced styling for has sparked interest from users who simply like its looks, said builder officials during a ride-and-drive event April 6 at Kenworth’s plant in Chillicothe, Ohio.
And driving on roads near the plant showed a surprisingly tight turning radius, especially with wide-base wheels and tires on the demonstration trucks. These were a five-axle concrete mixer and a four-axle dump, the prime applications for the T880S, which will replace the vocational W900S in KW’s product lineup.
The sharp turnability was immediately evident on the first turn I took in the mixer, which soon verified that 90-degree corners were no problem. Past KW’s with a forward-placed steer axle that I’ve observed and driven were somewhat ungainly in tight turns, whether traveling forward or while backing. So the good maneuverability was a welcome change.
One reason it performs well in corners is an offset in the front wheels, which puts tires further from the frame and steering gear and allows a tighter wheel cut, said product planners led by Kurt Swihart, marketing director at KW. The steering gear is still outside the frame rails, which can be expected to block a tight cut, but not here.
Both trucks had powerful engines and accelerated well. The mixer had a 430-hp Paccar MX-11 driving through a 7-speed Allison 4700 automatic, while the dumper had a 510-hp MX-13 running through an 18-speed Eaton UltraShift Plus. The self-shifting transmissions made both trucks easy to drive and allowed me to concentrate on things like the trucks’ maneuverability. Air disc brakes on the steer axle are standard with Kenworth, and the mixer had ADBs all around, so the trucks also stopped nicely.
Both rode well, too. The mixer drum was empty so there was some bouncing on bowed pavement as the 20,000-pound front axle was lightly burdened. The dumper, with about 10 tons of sand in its bed, was understandably steadier; also, its 20K steer axle sat on 16,000-pound springs, which were more forgiving while running over rough pavement.
Like the current T880 (and the T680 highway tractor), the S-model uses the roomy 2.1-meter-wide cab instead of the narrower cab of the T800 and W900 series. The demo trucks Thursday were comfortably trimmed and outfitted, with touches of bright-metal trim around gauges and in the HVAC knobs and an altogether premium feel even though the Diamond package in both is no longer top-of-the-line as it was decades ago.
The T880S is now in limited production at Chillicothe, but should account for about 20% of T880-series business, officials said. The setback axle on the current T880 is more usable for running within weight laws in most states, as well as over the road. Not that a T880 is aimed at highways uses: It’s a vocational truck and Kenworth doesn’t intend for it to be an on-road freight carrier.
So the interest in the T880S that KW has gotten from some non-vocational customers is curious. The new model’s flat face provides a hint of traditional style and some guys really like that. So yes, the “S” might be found as a regional tractor and who knows what else, in addition to its expected on/off-road applications.
By the way, the 880S is the first Kenworth T-model truck with a forward-set steer axle. Previously, T’s by definition have rear-set axles and the W-series meant axle-forward. This was intensely debated by people at Kenworth’s headquarters near Seattle, Swihart had previously said. Ultimately, they decided that application is more important than axle configuration.
The W900S, which the T880S will replace probably later this year, has a sloped hood like the venerable T800 but has a forward-set steer axle, so is something of an oddball in the lineup. Its primary use has been as a concrete mixer chassis. Also, when KW fans see “W,” they think of the long-hood W900L, the traditionally styled highway hauler. Putting all vocational trucks under the T banner makes more sense for KW planners, and probably for customers.