VHD Tractor Ventures Off-Road

March 27, 2015

Volvo Trucks North America is known primarily for its comfortable road tractors, but it also makes vocational models called VHD, for Volvo Heavy Duty. The VHD has a stronger chassis and other features to endure the rigors of off-road service, but retains much of the interior style and grace of the limousine-like VN highway tractors. VHDs might not be thought of as a typical dump or mixer truck, but they can be that and much more. And they’re good to look at, with stout yet curvaceous lines that at once suggest toughness and modernity.

Test Set

  • Tractor: Volvo VHD84FT, 6x4 conventional day cab, w/ 43-in. sleeper, BBC 113.6 in., GVW 76,600 lbs., GCW 110,000 lb.
  • Engine: Volvo D13, 12.8 L, 500 hp @ 2,100 rpm, 1,750 lb.-ft. @ 1,100 rpm, w/ engine and exhaust brake; EPA-’13 legal
  • Transmission: Volvo I-Shift, ATO2612D 12-speed automated mechanical
  • Front axle: 14,600-lb. Volvo VF14 w/ TRW THP 60 steering on 14,600-lb. parabolic leaf springs
  • Auxiliary axle: 13,000-lb. Hendrickson Composilite SC13 w/ Meritor 15x4-in. S-cam drum brakes
  • Rear axles: 46,000-lb. Meritor 46-160 w/ 3.73 ratio and full-locking diffs, on Hendrickson Primaax air-ride
  • Wheelbase: 258 in.
  • Brakes: Meritor Q+ S-cam drum w/ Bendix ABS and automatic traction control
  • Fuel tanks: Two 75-gal. 22-in.-diameter polished aluminum
  • Tires & wheels: Michelin 11R24.5 on Alcoa severe-service polished aluminum discs
  • Fifth wheel: SAF-Holland FW35 on 24-inch slider
  • Trailer: 48-ft. steel flat w/ concrete block load

They’re nice to drive, too, as I’ve found over the years. In March of 2014 we featured a VHD dump truck with an advanced I-Shift automated mechanical transmission, but it’s been more than seven years since I drove a VHD tractor. That one had a short sleeper needed in certain operations where legal bunk time had to be taken far from civilization, but our subject this month is a day-cab set up for heavy hauling both on and off road.

I bagged some wheel time in this tractor while visiting Volvo’s New River Valley assembly plant at Dublin, Va., last fall. Driving time was limited because there were other rigs to handle, so I didn’t go far with the VHD: out of the plant area to Interstate 81, south (geographically southwest) for about 25 miles to a turnaround point where I shot some photos, then back to the plant. It was enough to experience the tractor’s attributes.

“It’s an oil field truck,” explained Jason Spence, a marketing manager who pointed out the tractor’s special equipment prior to our drive. The build sheet says “tractor/lowboy trailer,” so yes, it could be involved in oil or gas drilling and production, which would take a rig far off paved roads. That’s what distinguishes the VHD from the VNX heavy-haul tractor that I wrote about for the November ’14 Field Test article; the VNX is primarily a highway tractor while the VHD is on/off-road.

A look at the VHD’s Test Set box reveals some beefy special equipment, including an extra strong main frame, to stand up to twisting forces from uneven terrain, and high-rated axles, as the tractor’s gross combination weight rating is 110,000 pounds. Even so, the tractor’s stance is not overly high. Obvious is the steel-braced aluminum headache rack behind the cab; it’s got your back if something on the trailer busts loose in a wreck (heaven forbid) or under hard braking (you never know!).

Getting  in and out was rather easy because of the well-placed handles and wide steps, though I’d quibble with their vertical placement: The first step is no-sweat close to the ground, maybe just 14 or 15 inches; the second is what looks like almost 2 feet; then the third is another comparatively short up-hop onto the cab’s floor. So there’s no 1, 2, 3 rhythm. But that was my only gripe with the vehicle. Its ride quality is very good, in spite of necessarily stiff suspensions; and there was little road or engine noise while underway.

The cab is crafted of high-strength steel, which cuts weight over more common carbon steel, and is galvanized against rust. Doors close with a satisfying thunk, and inside, the driver’s workplace is very roomy, almost overly so, as this is the same basic cab as used on VN tractors that guys and gals have to live in. Then again, it can be outfitted with a two-place passenger seat if needed, though this one had two individual suspension seats. There’s an initial sense that this is a really wide truck, maybe too wide for a standard travel lane, but that fades after a few miles. Trim is pleasant in an automotive way, with a wide, curving dash containing the instruments and controls that were easy to see and use.

Side windows are big and dual-pane mirrors well placed, the windshield huge, and the sloping hood provides few obstructions, so a driver’s view of the road and jobsite in all three directions is very good. This being a day cab, there was also a rear window that is good for checking the whereabouts of the trailer’s rear while making tight right-hand turns or while backing, even if the headache rack blocked some of that view.

The steering column tilts and telescopes and pedals are well placed, so, with proper adjustment of the air-ride seat, most drivers should be able to find the correct position. A smart driver will study the multiple adjustments on this National Comfort high-back seat, and a wise boss will instruct him or her on the many possibilities, because bodies differ, and correct settings can make a big difference in supporting one’s buns, legs and back and staving off discomfort and pain during a long day or night of driving.

A VHD can be had with a 12.8-liter D13 or a lighter 11.8-liter D11, and we had the larger diesel. It was rated at 500 horsepower and 1,750 lb.-ft., so we never lacked for go power. That VHD tractor of 2007 had a Fuller 18-speed manual but this one had the I-Shift, and I had little to do but punch the proper pedals and steer, unless I wanted to play with the ratios for extra powering or stopping performance, the latter with the engine brake.

When traction is good, leaving the tranny to make the decisions works just fine, but I-Shift does have several control options for maintaining momentum when things are loose underfoot. I wrote about those in that dump-truck article last year, and drivers should learn or be taught what those can do. One difference with this tractor: The Performance mode, if selected, remains that way until the driver elects to go back to Economy. Controls are usually set to automatically return to E.

All in all, I was rather impressed with this VHD, as I have been with VHDs in every instance I’ve driven one. Its sales are not high, partly because of Volvo’s apparent preoccupation with highway vehicles, and also because there are plenty of worthy competitors in the on/off-road market, including from Mack, Volvo’s sister company known for its vocational models. VHDs remain worthwhile and well worth a look from any potential buyer.