Special HX

When a truck manufacturer announces a major product change, most of the time you can see it right away: a new headlight style, a splash of chrome, a roomier cab. But the latest A- and L-Line heavy-duty models from Sterling Trucks have an upgrade that’s beneath the surface: the trucks are riding on a new chassis.

With lighter frames, optional frame inserts, and new suspension options,
as well as an improved cab air suspension and a new cooling system, Sterling’s HX chassis replaces the HN80 chassis inherited when Sterling’s parent Freightliner LLC bought Ford’s heavy-truck works five years ago.

The HX was conceived to deal with the anticipated heat-rejection challenges of ’02 engines and thus the need for more radiator capacity, but these issues never really materialized. So you get the bigger, better rads anyway, with all the benefits you might expect. New radiator options, all of them crossflow designs, include capacities of 1,000, 1,200, and 1,400 square inches. Each has a new mount with two or three bracing rods and a new isolation system.
Still up front, the HX has an all-new accessory-drive system with self-tensioning belts and the industry’s first “scroll”-type air-conditioning compressor (made by Visteon). Used in high-end four-wheeler applications for several years, the compressor has fewer moving parts and “almost no wear points” compared to piston compressors, Sterling says. Its simple design is 35 per cent more efficient, demanding less horsepower of the engine than ordinary compressors. Exclusive to Sterling for two years, the compressor will be standard starting in 2004.

Sterling offers the HX frame in section heights of 10, 11, and, for the first time,
13 inches. Also new: full-length frame inserts; previously, only partial outserts were offered (they’ll be discontinued). Strength ratings are improved and optional RBMs up to five million inch-pounds are optional.

Body builders will be happy with the HX because every frame will use a standard layout of frame holes at regular spacings on a grid pattern (all mounting holes for crossmembers and other components adhere to the pattern). The idea is to simplify aftermarket body and equipment installation when you order the pre-punched mounting holes.

Front-axle suspensions now include taper-leaf springs in capacities up to 20,000 pounds, and multi-leaf designs good for 23,000. There are also maintenance-free options up to 14,600 pounds.

New for A-Line on-highway trucks and tractors is the option of lightweight fibreglass composite springs that save 77 pounds. An AirLiner suspension, an existing Freightliner option, is also available for those who want air up front.

The new TRW THP60 high-pressure steering box is standard. Its compact nature allows for a greater wheel cut. And at the back end there are new Hendrickson options like the Haulmaxx walking-beam, Primaxx (an air suspension for vocational trucks), and an enhanced TufTrac two-stage suspension that improves ride quality in empty trucks.

For a casual onlooker, the only visible change to the HX chassis is the switch to cylindrical aluminum fuel tanks, now standard in a diameter of 23 inches with 25 inches an option.
More information is available from your Sterling dealer, or go online to www.sterlingtrucks.com.