Western Star is rolling out its next-generation vocational truck, the 49X – a modern and tech-rich takeoff of its 4900.
A clean sheet design built from the ground up, the 49X is engineered to be easier to upfit, and also features a lighter-weight chassis and cab.
The new model also debuts a new work-specific DT12 transmission.
“A vocational truck is a tool for a job,” said David Carson, Daimler Trucks North America senior vice president, vocational segment. “We’ve completely rethought the foundation of the 49X to make it easier to upfit, deliver greater durability, return greater payload and improve productivity at the jobsite.”
The 49X has been tested in some of the most grueling applications where it could be deployed, such as the oilfields of west Texas, plowing operations in New Hampshire and logging operations of British Columbia, Carson said.
“We have beat this truck to hell,” Western Star General Manager of Heavy-duty Vocational Platforms Tracy Mack-Askew said of the new model’s testing regimen.
The 49X, Carson said, was developed out of demand from Western Star’s work truck customers that wanted increased safety features and more modern technology found in the lineup. Part of the reasoning for retaining the 4900, he added, was that it allowed Western Star to continue to provide a product for “the customers focused on simplicity that is older in its design and features.”
Chassis. The 49X tips the scales about 350 pounds lighter than the current 4900 – a model which will remain in production alongside the 49X for the foreseeable future – thanks in part to its single-channel frame rail. For added strength, c-channel frame reinforcements also are available with Resisting Bending Moment (RBMs) up to 5.4 million. Multiple parent rail front frame extension options are available for applications requiring front-mounted equipment such as a plow.
Daimler Trucks North America Vice President of Vocational Market Development Samantha Parlier called the new chassis “the absolute cornerstone” of the truck.
Western Star said development work on the steel-reinforced aluminum X-series cab was the most extensive in its history, and was specifically designed for vocational applications by deploying advanced topology optimization that ensures rigidity and strength while determining where additional material was needed.
The cab – the largest in its segment, offering 10%-13% more space than competitors and 8% lighter – was safety-tested in multiple crush tests to ensure integrity in the event of a rollover. Full-vehicle shaker tests replicated 800,000 miles of use to test the cab mount system that uses outboard mounted vocational cab isolators for optimal stability and reduced fatigue to both the operator and the cab.
“This truck is so much lighter than the current product, yet it’s actually even more durable,” Mack-Askew said.
Added visibility comes from a sloped hood enabled by splayed frame rails, a lowered engine position and underhood engine air filtration, a 28% larger single-piece roped-in windshield and an optional three-piece rear window that is 77% larger versus the 4900.
A high-strength lightweight molded composite for impact resistance and durability uses a patented ISO Tech Hood Suspension system that behaves similarly to a typical coil-over shock suspension with spring and damper. The system isolates, absorbs and dissipates vibrations from the chassis when driving over uneven terrain to protect the hood from damage and cracking.
Clear back-of-cab packaging allows for easier upfit with features that include forward-mounted DEF tanks, a standard in-cab battery box, multiple air tank mounting locations, an air dryer mounted under hood (SBA) or under cab (SFA), optimized fuel tank sizes, a compact Detroit aftertreatment system and functional dual vertical exhaust stacks.
The new Detroit DT12 Vocational automated manual transmission series is available as either the DT12-V or the DT12-VX – a transmission that was born following investments totaling more than $100 million, according Parlier.
Rated up to a GCWR of 330,000 pounds, the transmissions can be mated to either the Detroit DD15 Gen 5 engine or the Detroit DD16.
Both transmissions include side PTO capabilities for added flexibility, as well as unique and customizable work application modes and shift map strategies for all types of terrain. A Rock-Free Mode allows the 49X to free itself from wheel-stuck situations, an Off-Road Mode enables smooth driving on extreme terrain such as logging roads and rock quarries and Power Launch provides powerful takeoffs while protecting the clutch and driveline. There is also an Economy Mode for more fuel friendly on-highway driving.
Models can also be spec’d with a Cummins engine, and Eaton and Allison transmissions.
All 49X models come with a standard interior with upscale appointments, including metal accent. An optional premium trim package introduces richly crafted materials, including wood-grain and diamond-stitched seating. All models feature a wrap-around dash that puts the command center and b-panel in the driver’s line of sight. On the b-panel, a flex panel houses tablet prep or can be configured for an additional 12 switches or 10 gauges. Along with a QuickFit Dash Access designed for seamless telematics or other device integration, equipment control and device access is within easy reach.
Technology and safety
The 49X is the first Western Star to feature the Detroit Assurance suite of safety systems – the most advanced collision mitigation system in the vocational segment – including Side Guard Assist (SGA), Active Brake Assist 5 (ABA5), Tailgate Warning, Adaptive Cruise Control (ACC) to 0 mph, Lane Departure Warning, Video Capture, Intelligent High-Beam and Automatic Wipers/Headlamps.
A dual-stage LED headlight system features an internally printed heat grid and ambient air temperature sensor that can melt three millimeters of ice in less than 10 minutes at -40 degrees Fahrenheit or burn through condensation in warm, humid environments. Combined with a 45-degree light pattern, the headlight system provides uniform long and wide illumination.
Wire routing and clipping was reimagined with the truck’s work environment in mind, leaving space for mud, snow and ice to fall through and to not build up behind the rail while also preventing chafing.
Parlier said Western Star spent about six years developing a C-bar mirror system that features door-mounted mirrors that mitigate the effects of chassis and engine vibration (regardless of engine RPM) to keep them stable and usable in off-road or paving applications where visibility by the operator to the crew at the back of the truck is critical.
“If that mirror is vibrating,” she said, “not only is it unsafe, you can’t effectively do the job.”
“A 300 pound man can hang from that mirror and do pull ups,” added Mack-Askew.
Door opening angles of 70 degrees, five handholds and step treads widened by half an inch and constructed as a staircase help facilitate safer entry and exit from the cab. The steps start closer to the ground and use a volcano tread for confident footholds with high traction and added toe clearance, while mud, dirt and debris pass through.