KW T880S Fills ‘Bridge’ Need, Turns Surprisingly Well

By Tom Berg, Truck Editor | April 7, 2017

Weight laws in so-called bridge-formula states encourage the use of long wheelbases with forward-set steer axles, and Kenworth’s new vocational T880S fills that need in up-to-date fashion. Until now, the T880 with its roomy, 2.1-meter cab came only with a setback front axle, and KW customers needing the forward-placed axle had to buy older models. No more.

Kenworth officials had dumper and mixer versions of their T880S on hand for driving this week at the assembly plant in Chillicothe, Ohio, and yours truly drove them both. I found them pleasing to look at and comfortable to sit in and drive. But I was surprised to find that, in spite of their set-forward steer axles and wide tires, their turning circles were rather short, making them agile and easy to maneuver.

This is true even though steer gear on the new model is still mounted outside the frame rails. The trick is using offset wheels that puts the tires further out and gives the wheels more room to cut before they must be snubbed to avoid rubbing on the gearbox, said product specialists on hand at the demonstration.

Also surprising is that the T880S’s brawny, flat-faced styling has sparked interest from nonvocational users who simply like its looks, the specialists said. So don’t be surprised to find highway-tractor versions of the new model, though for a while it will fill strictly vocational needs. The T880S will probably replace the W900S in KW’s product lineup later this year.

Both trucks at the demo had powerful engines and accelerated well. The mixer had a 430-horsepower Paccar MX-11 driving through a 7-speed Allison 4700 automatic, while the dumper had a 510-horsepower MX-13 running through an 18-speed automated Eaton UltraShift Plus. The self-shifting transmissions let me forget about changing gears and instead concentrate on driving safely and observing the trucks’ various characteristics, such as the good 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 McNeilus 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 Rogue bed, was understandably steadier; also, its 20K steer axle sat on 16,000-pound springs, which were more forgiving while running over rough pavement.

The demo trucks were comfortably trimmed and outfitted, with touches of bright-metal trim around gauges and in the HVAC knobs. It possessed an altogether premium feel even though the Diamond interior package in both is no longer top-of-the-line as it was decades ago.

The T880S is now in limited production at Chillicothe, which will ramp up soon. It should account for about 20 percent of T880-series business, officials said. The setback axle on the current T880 is more usable for running within weight laws in most states.

Interestingly, the 880S is the first Kenworth T-model truck with a forward-set steer axle. Previously, Ts by definition have rear-set axles and the W-series meant axle-forward. I’ll get into that and other details of KW’s newest model in a full Field Test in Construction Equipment’s July issue.