One thing truck builders do to meet varying operating needs is to tailor an existing model to a specific job. The example here is Peterbilt Motors' venerable 357. This vocational vehicle was previously offered with a forward-set steer axle best used in bridge-formula states. Now the 357 can be bought with a setback axle for states that allow high axle loads on relatively short wheelbases.
Earlier this year, Peterbilt announced the axle-back 357 in two bumper-to-back-of-cab measurements: 115 and 119 inches. The longer-BBC version, called the 357 Heavy Haul, is set up to pull weighty loads at sometimes low speeds. Among other things, that requires both a powerful engine and a large radiator to shrug off high heat without help from the ram-air effect present during highway cruising.
This 357HH tractor has a 625-hp Caterpillar C15 that's cooled by a radiator with a 1,440-square-inch core, which is about 20 percent larger than radiators on other 357s. Its wide hood and nose seems to thrust ahead of the rear-set axle, making for a brutish look that tells everyone that this truck means business.
Weight laws in Texas make it one of the states where the 357HH's axle configuration makes sense, and the tractor — the first one built and the only one in existence when I asked to drive it — was at Rush Peterbilt on Houston's east side, so that's where I went. Peterbilt spokesman Derek Smith had made the arrangements with the dealership and its next-door sister store, Rush Equipment, which sells John Deere construction products.
Our load was a Deere backhoe-loader aboard a 53-foot-long by 102-inch-wide Fontaine tri-axle lowboy. The Deere weighed only about 14,000 pounds, so a short equipment trailer would have sufficed. But I had asked for a lowboy and that's what the crew provided. The trailer had a manual gooseneck, which is also known as a "dropdeck."
But we had a problem: The trailer's nose was too low to slip the Pete's fifth wheel under, and lack of hydraulics meant the gooseneck couldn't be adjusted to match the tractor's height. The tractor's dump valve didn't lower the tandem's air bags much if at all. So I could not jam the fifth wheel under the nose without risking damage.
One of Rush Equipment's guys came up with a solution: He and another guy slinged the trailer's nose with a heavy cable and hooked it to the boom of a Deere excavator. Its operator raised the nose a few inches so I could ease the Pete under. The determined men labored in high heat and humidity, and we thanked them profusely for their hard work.
A setback steer axle provides more room for the front wheels to cut, which gives a truck a comparatively tight turning radius. Peterbilt engineers say it will cut a circle that's about 13 percent smaller than a regular 357. That's fine, but the trailer was still a bear to pull because of its sheer length and the absolute rear setting of its axles. Any sharp turn had to be taken wide to give the trailer room to make its swing.
Coming out of the dealership's driveway onto a freeway frontage road, I had to climb the opposite curb and move the tractor along the dirt and grass until the trailer's tridem cleared the fence, then swing the tractor back onto the pavement. For the rest of the trip I was careful where I went with this rig because I didn't want to find myself boxed in.
For the most part I stayed on freeways, driving a roundabout route west on Interstate 10 and north on State Route 45. Then I backtracked to I-610, which took us east and south to the dealership back near I-10. Lanes were narrow on older stretches of the freeways closer to the city's core, providing maybe a foot on either side of the wide trailer. Traveling on these was a trifle tedious as I had to constantly watch the trailer's position through the mirrors. Using the Peterbilt's winged nose ornament to sight along our lane's right edge helped here. Newer segments had wider lanes where I could relax.
With 625 horsepower and a light load, we accelerated almost effortlessly and cruised easily. I never needed the transmission's Low gear and instead started out in 1st or 2nd. I split the 18-speed's main gears mostly for fun and otherwise drove it like a nine-speed. The engine spun a bit over 1,600 rpm at 65 mph in top gear, so the tractor was as sufficiently long-legged as it was low-geared for starting out with heavy loads. The tranny was new-truck stiff but nonetheless shifted smoothly and with a nice, tight feel to the lever.
As we turned around at a road junction north of the city, I was reminded that while side-mounted exhaust stacks look neat and keep the rear deck clear for extra-long loads, the one behind the driver's window blocks his view of what's happening with the trailer's left-rear corner during tight turns. I could've leaned out the window to look, but found that the big convex spot mirror was enough to watch the tridem's wheels to be sure they weren't running over someone's toes.
In right turns I could look over my shoulder and out the cab's big rear window, which gave me a clear view of the entire trailer. In sharp turns it was nice to know that I could aim the nimble Pete's nose far outside the circle needed by the trailer, then easily cut back in.
The 357HH will come standard with a tilting steering wheel, but this pre-production tractor didn't have it. The wheel was higher than I'd have set it, but not too high to be uncomfortable. However, its thick rim and wide spokes blocked my view of several gauges and the warning light display.
As I leaned forward, I saw a warning message: "Trailer ABS." The tractor's electronics had sensed that the 10-year-old trailer had no anti-lock braking system. That's nice to know because in a panic stop, especially on slippery pavement, the ABS-equipped tractor will stay in line but the trailer's tail may swing out as you jam on the binders. Of course, a better idea is to watch the traffic so you don't have to brake hard in the first place.
Before we knew it we were back at Rush Equipment, where the crew promised to look after the rig the following workday. Outside, humidity and temps were both in the oppressively uncomfortable 90s, but we had been fine with the Pete's powerful air conditioning on.
Smith, who occupied the passenger perch, said he enjoyed the trip. His solid-mounted seat caused him no discomfort because the tractor rode on two sets of air bags, one over the tandem and another at the cab's rear mounts. There was just a hint of front-end hop over bowed concrete. My air-ride seat thus got only a slight workout. So, Peterbilt's 357HH is a special tractor for specialized hauling that looks like a brute but behaves like a gentleman.