Product Evaluation: Peterbilt 335

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Typical vehicle specifications
Wheelbase: 150-274 inches
Engine: Caterpillar C7, 190-300 hp; Cummins ISC, 240-315 hp
Transmission: Eaton Fuller manual, 6-, 9-, 10-, 11-speed; Eaton Fuller automated, 6-, 10-speed; Allison automatic, 4-, 5-, 6-speed
Clutch: Eaton
Fuel tanks: Various, including round aluminum; rectangular steel, 50-100 gal.
Front axle: Dana Spicer, 8,000-18,000 lb; Meritor, 12,000-14,600 lb
Rear axle: Dana Spicer, 19,000-40,000 lb; Meritor, 21,000-40,000 lb
Brakes: Hydraulic, full air
Wheels: Steel, aluminum, 19.5, 22.5, 24.5 in.
Tires: Bridgestone, Michelin

Although Peterbilt’s 335 medium-duty truck/tractor is more attractively styled than the 330 model it replaces, CCJ’s Product Evaluation team also found its inner beauty, noting improvements in maintainability, ergonomics and performance.

With GVWRs ranging from 26,000 to 58,000 pounds, and wheelbases stretching from 150 to 274 inches, the Class 6-7 335’s list of intended applications reads like a business-to-business phone book. Typical uses include inter- and inner-city P&D, construction, fire and rescue, beverage, municipal, refuse and many other vocations.

Powertrain options are varied appropriately to suit the need, with a choice of 190- to 300-hp (@2500-2400 rpm) Cat C7, or 240- to 315-hp (@2400-2200 rpm) Cummins ISC engines, with 520-860 pound-feet (@1440 rpm) and 600-950 pound-feet (@1300 rpm) of torque, respectively. They’re mated to 6-, 9-, 10- or 11-speed Eaton Fuller manual, 6- or 10-speed Eaton Fuller automated, or 4-, 5- or 6-speed Allison automatic transmissions.

Power gets to the road through Dana Spicer 19,000- to 40,000-pound or Meritor 21,000- to 40,000-pound drive axles, riding on Peterbilt air, or Reyco taper-leaf suspensions.
Brakes can be hydraulic on the Class 6 edition, with full air for Class 7s.

Outside-in …
On initial, external inspection at Hunter Jersey Peterbilt, Clarksburg, N.J., evaluators praised the 335’s new looks, with its all-aluminum, riveted and bonded cab, and integrated, halogen headlights, now in a sleek housing also containing the previously outboard-mounted parking lights and turn signals. They also liked the larger side and rear windows, and were glad to see Peterbilt’s signature, long-piano-hinged doors. “You can hang on those doors when opened, and you won’t hurt ’em,” said one. They also were pleased to learn that the hinges can be removed without special tools.

The two-piece windshield also found favor since, in the event of damage to one side, the whole windshield needn’t be replaced. A couple of evaluators, however, wished that Peterbilt had carried the multi-piece theme on to the hood and fenders. These come as a one-piece, “Metton” composite affair, which the company says retains its dimensional stability better, and is easier and less costly to make, since only one mold is needed. Evaluators did appreciate that the rearmost, quarter-sections of the fenders can be removed by backing out four bolts each, allowing for individual replacement, as well as easy access to the rear sides of the engine.

The 335’s perfectly clean, Huck-bolted frame rails, evaluators thought, should expedite body mounting and hold up well in service. They also were pleased to see a cab air suspension nestled between those rails, under the back of the cab. The stoutly mounted exhaust system, also at the back of the cab, drew particular praise from one evaluator, who had had more than his share of broken exhaust mounts and damaged cabs.

One perceived maintenance nuisance took the form of the fuel-gauge sender mounted at the tank’s top center, directly under the cab floor. “We need to replace senders at least once or twice during a truck’s life,” an evaluator said. “And with this setup, you need to loosen the straps – which invites bolt and strap breakage – then rotate the tank outboard to remove the sender. And rotating even a partially full tank is quite a job, so you need to time the job for when you think the tank is nearly empty.”

While evaluators realized that’s how the tank is supplied by the vendor, they suggested that the vendor move the sender aft, to the part of the tank that’s exposed, or that a snap-plug-covered access hole be cut in the cab floor.

… Inside-out
Turning their attention to the 335’s innards, evaluators thought the hood’s “anti-blowdown” catch, with the release cleverly recessed into the hand hole behind the grill-surround, was a great safety idea. “That should save a few headaches,” quipped one.

Once under the hood, evaluators questioned the engine-mounted, upper radiator supports. “They’re going to make valve-cover removal more difficult,” said one. However, Peterbilt engineers say they’ve found that this design makes for better radiator and support durability. Also, with virtually no relative motion between the engine and radiator, the fan shroud can be closer to the fan-blade tips, allowing for more air pull-through and improved cooling. Moreover, they said, the support ends are bushed, so only two bolts need to be removed; then the supports can be swung up and out of the way for valve-cover access.

Overall engine access was found to be good, if a little tight on the left side, where the oil-fill point would pose no problem for a technician with a shop-pump oil-delivery wand, but could get messy for a driver trying to add oil from a gallon jug through a funnel. Another vendor issue, it turns out. According to Peterbilt, that’s where Cummins puts the fill point. Caterpillar uses a different location.

The team noticed that most underhood wiring and connectors are well shielded, with relays mounted inside the cab. And no electrical components are mounted under the windshield-washer fluid or coolant reservoirs where spills and eventual corrosion are inevitable. However, evaluators were puzzled by the lone exception to electrical-component protection – a relay mounted at the top of the firewall. According to Peterbilt, it’s the starter relay, and its placement is primarily a design carryover from earlier versions. The relay used to be a high-amperage, magnetic job, so it made sense to keep it outside of the cab. The relay now is electronic and will likely be moved inside with the other relays in future designs.

Also under the hood, evaluators were happy to see grease fittings on all front chassis components, including spring-shackle bushing pins, but one lamented that roller-bushings aren’t available on the 335.

Moving on to more driver-oriented aspects of the vehicle, evaluators had no trouble whatsoever jumping in or out, thanks to an 85-degree door swing, well-placed grab-handles, and no interference from the steering column. “On so many trucks, when you go to swing your feet out, your knees hit the column,” said an evaluator. “Not so, here.”

The team was impressed with the interior’s open feel, afforded in part by a flat floor with no doghouse intrusion in the center. They also liked the clean dash with classic, round, analog gauges, which are individually removable for service or replacement. But they wondered about a bank of switches hidden from a driver’s eyes by the turn-signal housing. Peterbilt says that, except for major instruments, the dash is fully customizable and, for whatever reason, that’s where the customer who spec’d our subject truck wanted them.

The team did offer two interior suggestions: First, they said the brake valves would live longer if they were angled toward the driver, rather than perpendicular to the dash, because that would reduce the likelihood of a driver applying side force to the valves, which causes accelerated wear of internal components.

Second, they thought the evaporator housing in the passenger footwell was a little too close to the seat, and would wind up getting kicked and possibly damaged. Peterbilt said it would investigate and evaluate both suggestions.

Taking turns at the wheel, all agreed that the standard tilt/telescoping feature was a major plus, and they said forward and side visibility was excellent. They also commented on the nearly vibration-free mirrors, which have been moved forward and mounted on the cab, not on the door as on the 330. “I like having the mirrors being a little further away like this,” said one team member. “You don’t have to turn your head as much as you do when they’re mounted closer. You can spend more time with your eyes on the road.”

Roadwise, evaluators again agreed, commenting on the quiet, smooth ride – even with no body mounted – and the high degree of maneuverability, which is largely a result of the 335’s 50-degree wheel cut.

As one evaluator summarized, “It’s really comfy. This truck is one nice ride.”

All in favor?
In the end, the 335 gathered far more “ayes” than “nays,” leading an evaluator to joke, “Can you deliver 10 of these tomorrow?

“Seriously,” he added, “This is, overall, a really nice truck. Some lucky driver is going to enjoy it.”

The Peterbilt 335 Product Evaluation Team (from left): Mike Petrshin, shop manager, Old Dominion Freight Line, Jersey City, N.J.; Bruce Grankowski, maintenance superintendent, Middlesex County Utilities Authority, Solid Waste Division, East Brunswick, N.J.; George Husack Jr. and George Husack III, George Husack Inc., Schnecksville, Pa.


The fleet operator’s opinion
CCJ Product Evaluations are not performed by CCJ editors. They are done by a team of fleet equipment managers, chosen for their experience with the type of product being evaluated. Editors report evaluators’ opinions, not their own. Comments are not directly attributed to specific evaluators to avoid the appearance of individual endorsement or criticism of products.

An evaluation is based on a driving test and design assessment (which sometimes involves some disassembly of the vehicle), followed by a discussion among the evaluators and manufacturer’s representative(s). Manufacturers are given ample opportunity to respond to any criticisms.

As always, we welcome your comments and suggestions.