Folks who have been running up and down the interstates for many years in Volvo’s popular highway tractors might want to alter their careers by staying home and doing some local trucking. And for them, the Swedish-American builder has just the thing: the VHD vocational model, which uses the same basic and roomy cab from the VN series, along with comfort and safety advantages that Volvos are famous for. Inside, they teem with electronic safety and communications equipment to make drivers’ and managers’ days more efficient. They are also extra tough for the rigors of off-road running.
Look inside the VHD vocational trucks.
Our featured trucks possessed modern, edgy styling—especially along the fenders—and squinty housings for the LED headlamps. VHDs were restyled in 2019, about the time of the start of the Covid pandemic that muted any attention the freshened models received. North America, anyway, has mostly returned to normal activities. Thus the timing for this driving experience with the redone series.
Gathered at Volvo Trucks’ Customer Center adjacent to the sprawling factory in Dublin, Virgiania, the two VHDs were set up as dump trucks, one with a forward-set steer axle and the other with an axle-back setting. They are aimed at states with bridge-formula and axle-weight laws, respectively, so they differ in wheelbase and other chassis matters. Both were 300 series with non-sleeper daycabs (the 400 series denotes a 42-inch-long flat-roof integral sleeper). They wore fashionable storm-gray metallic paint, a tasteful amount of bright-metal trim including massive grille guards, and centrally mounted tow hooks rated for 80,000 pounds.
Each had a Volvo D13 diesel (the only other engine choice is a D11) driving through a 13-speed I-Shift HD automated manual transmission and Meritor rear axles cushioned by Volvo’s T-ride suspension. Ahead of the tandems, each had a single lift axle: a rigid dual-wheel pusher on the axle-back vehicle, such as tri-axle dumpers you see in Pennsylvania, and a steerable unit with large single tires for the axle-forward truck. In “super dump” states, trucks with forward-set (and sometimes setback) steer axles have longer frames and two, three, or even four steerable pushers; but for these demo trucks, Volvo was showing off its ability to mount a single lift axle at the factory.
Guided by Andy Hanson, Volvo’s vocational segment manager, I drove both trucks around the Customer Center’s premises that include a dog-bone-shaped paved track that is a little over a mile in length, accelerating to 55 and 60 mph, then braking to test stability during deceleration. We also made several trips over a gravel off-road course with short straightaways, brief but steep hills, and depressions that gather water when it rains, though they were mostly dry on this late-May day. Hanson said all new trucks are run over the track to test for any flaws that escaped inspectors on the assembly line.
Test drive highlights
These dumpers did not seem to have any problems, and mostly I observed how they felt and handled. They were rather nimble, even with dual steering gear and wheel stops necessitated by their 20,000-pound axle ratings and beefy front tires. I did circles in a wide spot on the off-road course to compare the two trucks’ turning arcs; sure enough, the axle-back VHD, whose wheels had room to cut a little sharper, had a smaller radius—about 20 feet or so—than the axle-forward truck.
Acceleration was brisk as the dump boxes had only moderate loads, and the I-Shift automated trannies changed gears quickly and efficiently in most circumstances. While cresting a steep slope, though, one transmission’s controls had to think a moment or two before deciding on a proper gear, then went for it and we continued on our way. We never lacked for ratios, especially with the extra creeper gear that is added to the standard 12-speed gearbox (a 14-speed version with two creeper ratios is also offered). Even on tough upgrades, the truck started out strongly and always applied authoritative power, and always with fast but smooth clutch applications. A hill-hold feature applies the brakes when the truck stops on an upgrade, then releases them after three seconds; by then I was back on the accelerator and the truck resumed climbing.
Hanson demonstrated one I-Shift feature that mimics a driving trick known by experienced gear jammers who find themselves stuck in mud or sand: Hold the gearshift’s thumb-actuated rocker switch up and floor the accelerator; the engine revs to 1,300 rpm and holds, with the tranny in a temporary neutral position. Then release the switch and power surges back through the gears to the rear wheels, breaking them free, and the truck moves forward. There’s no banging sensation, just abrupt and smooth power.
This brings to mind an observation I made years ago: Automated gearboxes are great on-road, where their going-through-the-gears, solid power delivery is satisfying to someone who finds joy in driving. They still do rather well off road, and do even better if the driver knows its tricks, like the one just described. An Allison torque-converter automatic, however, needs less skill from a driver, who can just leave it in Drive and mash the gas, and power flows continuously with no pauses. And yes, Volvo will sell a VHD with an Allison, but it’s more expensive than an I-Shift HD; and it will also equip VHDs with less costly Eaton manual trannies, for that matter.
By the way, an I-Shift works as well going down the ratio ladder as up. Crisp downshifting was particularly useful when the engine brake was turned on. This way engine revs were kept relatively high, around 1,400 to 2,000 rpm, so the retarder worked hard to control the truck on downgrades. Along with that came the snappy rapping sound from the exhaust as the engine acted as an air compressor and slowed the driving wheels. It almost goes without saying that service brakes were likewise strong, but they were needed less, thanks to the engine retarders.
One useful option on the VHD and other models is Volvo’s Dynamic Steering, which employs an electric motor on the steering column to add torque to a driver’s steering effort. To demonstrate the ease of control, Hanson had me steer into a deep concrete-lined gutter along the left side of a trail. I expected to have to fight the wheel to retain control, but not so with this feature; I didn’t even have to grip the steering wheel hard as we cruised along the trench, left wheels in it and right wheels up on level pavement. The device is shared with Mack, a sister company under Volvo Group ownership, where it’s called Command Steer.
Volvo’s biggest sales success is its highway tractors, and Mack is proud of its image as a dominant builder of vocational trucks, including dumpers and mixers. Most of the brands’ dealers sell both makes and seem to play along with each builders’ perceived strengths. So Volvo’s VHD has just a small share of vocational business. But that makes it distinctive, it seems to me, and the VHD should be appealing to ex-highway drivers who know of Volvo’s virtues, and to anyone who appreciates comfort and capability.
