Peterbilt Shows New Tandem Air Suspension, New Standard Drive Axle

May 1, 2001
Peterbilt Motors Company recently announced new suspension, engine, drive axle, and appearance packages for its highway tractors. The introductions came

Peterbilt Motors Company recently announced new suspension, engine, drive axle, and appearance packages for its highway tractors. The introductions came at the Mid-America Trucking Show in Louisville, Kentucky.

The suspension, engine, and drive axle announcements apply to all Peterbilt highway tractors. In addition, Pete has a new chrome appearance package for its Model 387 low drag tractor. The new 38,000-lb tandem suspension is known as Flex Air and is a hybrid of leaf and air springs. Installed weight of a Flex Air suspension is 400 lb less than Pete's Low Air Leaf suspension. The new suspension offers low chassis height and improved ride for refrigerated and tank applications, Peterbilt officials said.

The new suspension is a highly modified trailing arm design with a lightweight, stiff aluminum beam connected to a small semi-elliptic taper leaf spring at the leading end and supported by an air spring aft of the axle shackle. The extreme aft end of the suspension arm connects to a shock damper. A positioning rod connects each upper suspension bracket to each axle shackle. Suspension brackets, shock damper brackets, and air spring support beams are aluminum for low weight.

Easy Alignment

Ease of service is designed into the suspension. Welding at the axle seats has been eliminated to make axle alignment and pinion angle adjustments easier. All pivot points utilize rubber bushings to eliminate the need for lubrication.

Flex Air suspensions will be available on Model 379, 387, 385, and 378 Peterbilt tractors.

The lightweight suspension can be matched with Dana Spicer's new Premium-40 tandem drive axle, which becomes Peterbilt's standard offering as of May 1, 2001. With 40,000-lb capacity, the DSP40 is designed for tractors with high horsepower engines pulling heavy loads. It can handle 600 hp and 1,850 lb/ft torque easily and carries a five-year or 750,000-mile warranty.

The new drive tandem uses the Micro-Lip XL seal and slinger system to retain lubrication and prevent outside contamination. Hypoid gearing is available in a full range of final drive ratios. A gerotor lubrication pump is available as an option as is track width up to 78 inches. Lubricant drain interval can be extended to 500,000 miles.

The DSP40 becomes the standard drive tandem for Peterbilt Models 387, 385, 379, 378, and 362. In addition, it is optional for Models 357, 330, and 320.

Peterbilt has an exclusive agreement with Cummins Engine Company for 14-liter engines rated at 475 hp. The new N14-475E becomes available in mid-2001 for highway and vocational applications. Pricing for the engine with the new horsepower rating is equal to that of Cummins' N14-460E. Power can be uprated to 525 hp, an important factor in vehicle resale value.

The company offers the new engine because 475 hp is the dominant engine rating choice of Peterbilt customers, says Nick Panza, Paccar vice-president and Peterbilt general manager. The engine is available in most Peterbilt tractors, including the new long-length Model 387 low-drag conventional.

The entire Peterbilt product line can be ordered with new aluminum disc wheels that are three pounds lighter than previous wheels. On a tandem drive tractor, the new wheels will save a total of 30 pounds. In addition, the wheels have chamfered hand holes for improved appearance and a more comfortable grip during handling.

The new wheels are the same thickness as previous wheels and are available in all current size and finish options. All Peterbilt vehicles ordered after January 22, 2001, will be delivered with the new lightweight wheels.

Peterbilt continues to develop its low-drag Model 387. First introduced as a medium-length conventional, a long-length version was shown at Mid-America in 2000. For 2001, Peterbilt has added a new custom chrome appearance package that includes an aluminum stainless steel clad bumper and chromed mirror housings. The stainless steel surface on the bumper is 10 times thicker than conventional chrome plating. The aluminum bumper structure is about 50 pounds lighter than a comparable steel bumper with chrome plating. The bumper is covered by a five-year warranty. The new Model 387 appearance package will be available as a factory-installed option in Summer 2001.