Medium- and Heavy-Duty Roll into 2006

Traditionally, medium- and heavy-duty truck models have longer product life spans than their light-duty counterparts, which see significant changes almost every year. Yet, there has been a flurry of activity in the medium- and heavy-duty marketplace this year. Equipment Today has condensed the latest introductions for 2006 into the most significant changes that could affect your vocational fleet.

International Truck and Engine Corp. launches the 4100 Class 5 conventional truck and model 7700, which can be configured to meet bridge formula requirements.

The International 4100, available in 17,800- and 19,500-lb. GVW, maintains all of the key benefits of the International 4000 series. This includes the Diamond Logic electric system.

Three cab offerings are available, including the standard cab available with air ride suspension, an optional crew cab or an extended cab.

Power is supplied by an International VT-365 engine rated at 230 hp and 540 lb.-ft. of torque, which is transmitted through an Allison 1000 Series transmission. Stopping power is provided by commercial-grade, four-wheel hydraulic disc brakes with 15-in. rotors.

At the heavy-duty end of the business, the International 7700 combines many standard features and benefits of the 7600 models with the chassis strength and packaging of the company's 5000i. These include set-forward 4x2 and 6x4 versions, as well as a set-back axle 6x4 version.

Two of the 7700 models feature a front bumper to axle setting of 29.1 in. and a frame system that optimizes payload weights for states that follow bridge formula limits. This includes the use of a 12.25-in. frame rail, which offers both weight savings and strength.

Freightliner has expanded its vocational offering with new options for its recently introduced Business Class M2 106V and M2 112V models. They include an all-wheel-drive (AWD) option for the Business Class M2 106V, and noise abatement packages for both the M2 106V and M2 112V models.

Optional factory-installed Meritor front drive axles are a part-time system that can be activated by the operator when AWD is needed during poor traction conditions. AWD can be engaged at or below 10 mph or while the vehicle is coasting on a level grade.

The axles utilize straight front-to-back frame rails, eliminating the need for a step frame for optimized cab height. The transfer case of the front drive axle is mounted between the transmission and the rear axle. The axle bowl is offset by 11 in. to the passenger side, matching the driveline angles and eliminating the need for a lift kit.

The 4x4 or 6x6 configuration is available on Business Class M2 106V truck models equipped with MBE900 or Caterpillar C7 engines. The ratings offered include 12,000-, 14,000- and 16,000-lb. front axles with a variety of single and tandem rear suspensions.

Noise abatement packages available for the M2 106V and the M2 112V create a better working environment for operators. The standard package features a decoupled barrier made from lightweight foam, which is spaced away from the firewall, engine tunnel and floor. This minimizes vibrations and blocks noise.

The premium noise abatement package is claimed to reduce interior cab noise levels by 3 dB, or 50% over the standard noise levels. This package increases the firewall barrier thickness by 50%. In addition, a damping layer is added to the floor, back wall and roof.

A tunnel/firewall engine noise shield can be added to help silence noise traveling from the engine compartment to the cab interior. A hood liner insulation engine noise shield option can be specified to reduce engine sound traveling from the engine compartment to the outside environment. Either shield option can be ordered with the premium noise abatement package.

For 2006, major changes have been made to the T800, W900 and C500 Kenworth trucks. The models have been converted to multiplex wiring and feature upgraded interiors, plus the T800 is now available with front engine power take-off (FEPTO).

The instrumentation systems' multiplexed design enhances reliability and greatly simplifies the wiring behind the dash. LED back lighting in the face plate and pointers makes it easier to read gauges and see warning lights.

Power door locks are now standard, with electric window lifts standard on the passenger side and optional on the driver side. Window, door lock and mirror controls are located on the door for easy access.

Two cab trim levels are available: the classic Kenworth Diamond and machine stitched with French seams. Both are available in four primary/trim color combinations.

Curved windshields are now available for the sloped hood W900, high and wide hood T800 and C500 vocational trucks. A flat windshield also remains available.

The popular Kenworth T800 short-hood model is now offered with FEPTO. This configuration is available with Caterpillar C11 and C13 engines up to 380 hp, and the Cummins ISL engine up to 350 hp.

Some unique features differentiate the T800 short hood FEPTO model from the standard version. Extended frame rails are available with a 66-in. bumper setting in dimensions of 11 5/8" x 3/8", 10 3/4" x 3/8" and 10 11/16" x 1/2".

The 950-sq.-in. radiator includes a modified bottom tank for PTO shaft clearance, and the radiator-mounted grille allows the hood to be tilted for daily underhood inspections without contacting frame-mounted equipment.

Earlier this year, Mack expanded its Granite line with the addition of the Granite Axle Back for customers seeking an axle back configuration in a modern, lightweight chassis.

The backbone of this truck is the company's vocational Cornerstone chassis, which uses 300mm tall rails. The rails are offered in 8-, 9.5- and 11.1mm thicknesses with a 90mm flange, as well as 11.1mm with a 105mm flange. Rails are tempered to a minimum 12,000-psi yield strength.

The standard UniMax steer axles feature sealed, unitized hubs specifically for vocational work. Rated from 12,000 to 23,000 lbs., these sealed axles are virtually maintenance free.

Location of the front axle is key on an axle back truck. The Granite Axle Back is a full 17 in. farther back than an axle forward. It measures 51.5 in. from the back of the cab to the center of the front axle. This allows the body manufacturer to transfer maximum payload to the front axle.

While many components are shared among the Granite family, there are a few unique features. The headlight is designed for vocational use with a Lexan covering that is more durable than sealed beam headlamps. Flexible fender extensions are positioned over the wheels to protect the hood and control splashing.

Peterbilt has unveiled electrical system improvements, new interiors and HVAC improvements for it 2006 model line, which includes the 379, 385, 378 and 357.

Gauge and instrumentation reliability has been significantly improved with the introduction of multiplexed wiring, which reduces the amount of behind-dash wiring for improved diagnostics and serviceability. An Electronic Service Analyst (ESA) tool allows service technicians to accurately monitor, troubleshoot and repair the electrical system by isolating sensors and gauges.

There are three new interior trim levels: ProBilt, Prestige and Platinum. The ProBilt is a base level interior specifically designed to meet the needs of vocational applications. It utilizes robust, easy-to-clean materials, and is available in Arctic Gray coloring. The Platinum level is the premium interior, while the Prestige level incorporates many Platinum level refinements and features. Both are available in four color options: Artic Gray, Burgundy Wine, Maritime Blue and Saharan Tan.

Side-View visibility has been increased by a re-styled passenger side door. The area where the top of the door meets the bottom of the window was lowered and angled approximately 2 in. in the front and 1 in. in the rear.

The HVAC system was completely redesigned using Computational Fluid Dynamics to boost performance and improve climate control.

In addition, the Caterpillar C9 engine is now an available option for the vocational Model 357. This can help take about 780 lbs. out of the chassis vs. a C11 for weight-sensitive applications.

The biggest news from Sterling Trucks this year is the addition of several weight-saving components. They include a full line of proprietary axles, a rear engine power take-off option for the MBE 4000 engine and an enhanced taper leaf front suspension.

The company claims its front axle design can provide up to a 28-lb. weight savings over similarly spec'd competitive axles. The kingpins are supported by needle bearings instead of bushings, allowing them to roll instead of rub when the axle is being steered. This should reduce service and downtime.

The rear axles include single and tandem models. Sterling claims the new design offers up to a 128-lb. weight savings over similarly spec'd competitive axles. Precision cut gears are designed to minimize frictional losses and transfer more torque to the wheels.

The rear-mounted power take-off (REPTO) option for the company's Mercedes-Benz MBE 4000 engine also offers advantages in terms of weight distribution. It is gear driven off the rear of the engine camshaft with a 10 o'clock output location, and it features a 1:24.1 output shaft ratio. The REPTO is an integral part of the flywheel housing and does not add to the engine length.

Class 7 and 8 model Sterling Trucks can now be equipped with an enhanced 12,000-lb. taper leaf front suspension. This lightweight, low-maintenance front suspension offers up to a 14-lb. weight savings when compared to the previous design. It comes equipped with maintenance-free rubber bushings with spring spacers to reduce wear and friction. Reduced interleaf spring friction results in improved ride quality.

Volvo Trucks North America
Volvo Trucks North America introduces a new player in heavy transport day cabs — the VT 800. This truck comes standard with a Volvo D16 that pumps out up to 625 hp and 2,250 lb.-ft. of torque.

This truck is well suited for heavy-haul flatbed or lowboy applications with big-block diesel power that can withstand demanding duty cycles. It is equipped with the Volvo Intelligent Torque (I-Torque) management system, which controls the amount of engine torque delivered to the driveline in any gear. This allows use on an optimized rear axle and suspension combination since it is possible to specify a lighter rear axle and suspension than would otherwise be required.
A Cummins ISX engine with up to 565 hp and 1,850 lb.-ft. of torque is also available.

Transmission choices include the Eaton RTO, RTLO, 10-, 13- and 18-speeds or the Eaton Autoshift 10- and 18-speeds.

A long Bumper-to-Back-of-Cab (BBC) helps provide a smooth ride. The cab was moved back 8 in., which isolates the driver from the engine.

The cab is made of robotically-welded, high-strength steel and meets all the requirements of the Swedish Impact Test. Cab doors stay closed during collisions, but open afterwards.

Western Star
Western Star Trucks has restyled its 109-in. BBC 4900 SA vehicle model with stainless steel side intakes, improved visibility and improved aerodynamics.

The company also announced that all of its models will offer the Hendrickson HAULMAXX walking beam suspension or the PRIMAAX air suspension.