"Baby 8” trucks save dollars at buying time, and with a properly reinforced mainframe, they can carry as much, axle for axle, as bigger, heavier models.
An example is Kenworth’s T370 conventional, which not long ago became available with an 18,000- to 20,000-pound steer axle. That and a 40,000-pound tandem gave this truck strong underpinnings and a gross vehicle weight rating of 58,000 pounds.
The extra-strong steer axle was requested by fuel-oil dealers in the Northeast, who want to haul as much product as possible in a truck with limited length, said KW executives at a show-and-tell at their plant in Chillicothe, Ohio. The conventional-cab chassis was fitted with a Seneca aluminum tank body that could hold 4,500 gallons among five compartments (four of 1,000 gallons and one of 500). Maximum payload for the tank was 42,000 pounds, according to the builder’s plate. Pumping and hose equipment was in a large cabinet at the rear.
My strongest impression of the truck was the high-capacity steer axle. With no load in the tank, the 18,000-pound taperleaf suspension was necessarily somewhat stiff. And the wide wheels and tires limited wheel cut and made for a large turning circle. Part of this was placement of the dual steering gear boxes outside the frame; wheel stops had to be set to avoid rubbing the 325-series tires against them. Wheel feel with the Sheppard gear was rather precise.
With limited turnability, I had to plan my maneuvers on Chillicothe’s city streets. I spun the steering wheel early while entering corners, especially right-hand turns, to avoid taking a lot of extra lane space. Regular drivers know this and maneuver accordingly.
The rear tandem rode rather well, even with no load, thanks to the Kenworth air-ride suspension. The tandem and the high-rated steer axle can stress the main frame, so this one is extra strong, with 3/8- by 10-3/4-inch main rails and a pair of heavy-duty bolted crossmembers at strategic spots.
The Allison automatic transmission was invariably smooth and responsive. It was a medium/heavy-duty 3000 RDS (rugged duty series), which is sufficient with Paccar PX-9 diesel engine ratings such as the 350 hp and 1,000 lb-ft. on this truck Those numbers are modest compared to bigger diesels, but the Allison compensates by sending continuous power to the rear wheels. And the midrange-size powertrain helps reduce cost.
So does the stout but compact aluminum cab, shared with other medium-duty T series trucks as well as older heavy-duty models. The cab is roomy enough for most drivers. Big people may be better accommodated with the 6-inch cab extension available on the T440 and T470, also medium-heavy models, or the Class 8 T800, while the newer T880 comes with a wider and longer cab.