JOSH LePage, vocational marketing manager of International Truck and Engine Corp's Severe Service Vehicle Group, believes that the process of spec'ing the right truck for municipal markets and other applications is like a three-legged stool.
The three legs are represented by the truck equipment manufacturer, dealer, and customer. If proper communication is not maintained by any one of the three, the stool collapses and the properly spec'ed truck is not received.
“The key is the relationship,” he said in his presentation at The Work Truck Show in Indianapolis earlier in the year.
He said the key areas of a chassis spec include the frame, front axle, front suspension, brakes, steering, drivelines, exhaust system, electrical system, front end, paint, clutch, engine, transmission, front axle and suspension, fuel tanks, and cab.
He said the backbone of any truck is the frame rails. Resisting bending moment (RBM) defines the strength. Options include accommodations package, heated polyurethane coating, single rail, partially reinforced “L”, and fully reinforced “C.”
Frame options
LePage said frame options include tow hooks, front tow loop, rear tow loop, bolt on front frame extension with reinforcement, and integral front frame extension.
“Is there going to be a tow plate installed on the rear of the chassis?” he said. “Is it going to be a pintle hook configuration? Is the truck going to pull a trailer? Do we need to put out front frame extensions? Are we putting a front-mounted PTO on that chassis?”
He said International offers pre-pierced frame rails, “which means that your body company doesn't have to sit there and drill these frames out. Sometimes it takes six to eight hours to drill a frame. It can be one hole or as many as 12 holes. So if you can get that information from the customer or from the body equipment manufacturer and get it to the OEM, they can work out a grid pattern and figure out where we can pre-punch these frames for you.”
He listed these bumper considerations: single piece, thickness, powder-coated steel, chrome, front bumper extension.
He said the spec considerations for front axles include: set back or set forward, axle capacity, and wheelcut.
“Does anybody know how much a plow weighs? About 3,000 lb, right?” he asked. “And if you have a 14,000-lb front axle on the chassis, and if there are sand and salt and chemicals in the back, that weight goes up to the front axle. A lot of customers are finding out they're overloading their trucks.
“The wheelcut depends on whether you're set back or set forward. Are you driving in a lot of cul-de-sacs? You need maybe a set-back axle with a little bit more wheelcut, which means you need a little narrower tire so that driver can make that cul-de-sac without stopping and backing up.”
LePage said that International has a computer simulation that will allow the user to to insert the tire dimensions and axle ratings, and obtain the exact wheelcut available.
Front suspensions
He said front suspensions are parabolic taper-leaf, multi-leaf, auxiliary suspension, and vari-rate taper-leaf.
Talking about the multi-leaf, he said: “We recommend it for snowplows because of the weight on the front axle, probably about 60% to 70% of the time. The only time that weight isn't there is when that plow is removed for summer activities.”
LePage listed the brake options: hydraulic brakes or air brakes (powder-coated air tank, air tank placement, air dryer, automatic slack adjusters, dust shields, color-coded brake lines, trailer brake accommodation, and air brake chassis packages).
“Hydraulic brakes are usually seen for lighter applications — inner-city driving,” he said. “Is it a cost savings to go with hydraulic over air? There are sometimes more maintenance issues with hydraulic. If you live up north, you have to make sure you have an air dryer on. Otherwise, you get a lot of moisture in the air tanks. If you live in the south, you have hydraulic brakes and overheating of the brakes that causes issues.
“Automatic slack adjusters are only as good as the setup. If the slack adjuster isn't set up right, it'll keep adjusting. And it'll adjust wrong. If you're in a dusty environment, you want to use dust shields to keep dirt contaminants out of the brake lining.”
He said exhaust options include right or left horizontal muffler/horizontal tailpipe, and right or left horizontal muffler/vertical tailpipe.
“With the advent of 2007 emissions, exhaust systems are going to be very critical in how you spec it out,” he said. “With Cummins, Cat, and International engines, once the exhaust system is set up, it will be certified by the EPA, which means you can't move it around. You need to make sure your equipment is outfitted correctly before you move the exhaust system around. Depending on your application, that will impact the amount of CA that you have available to you to mount your bodies.”
He recommended: always checking cab-to-axle and chassis packaging effects; verifying that the transmission PTO port clearance is adequate; always spec'ing a frame-mounted exhaust (“that reduces the noise and vibration going into the cab”); and check the routing of the exhaust and protection from road debris.
Alternator, starter options
Electrical considerations include alternator options (pad-mounted, amp capacity, and brushless versus brush type), battery options (cold-cranking amps, powder-boated battery box, battery-disconnect switch, jump-start stud, and sealed battery connections), and starter options (over-crank protection).
“What amp capacity do I need?” he asked. “Do I want brushless or brush type? How much current am I drawing? How many electrical components do I have on the chassis? Batteries are basically a shock absorber for the aternator and electrical system. As you turn on lights and wipers and strobes and operate machinery, you rob electricity out of the storage tanks. How quickly that electricity goes back in determines what size alternator you need to maintain voltage and amperage you need for your equipment.”
On the battery-disconnect switch: “In Michigan, all chassis now require battery disconnect. That's because a body builder got a hydraulic line too close to a voltage line battery and it sat there overnight. They came in the next morning and the shop had burned down. The line had rubbed through, shorted out, and caused a fire. I think you'll see a lot of states go to that.”
On sealed battery connections: “Electrical systems are being degraded by corrosive chemicals. If you can get a chassis that has a lot of sealed components built in, that will slow down the process.”
On the front end, the hood considerations include opening effort, repairability, air intake, ember air intake filter, and snow valve.
“If this is a fire truck, the ember air intake filter is a steel screen that will keep out 95% of the embers, especially in a fire situation,” he said.
He said a multi-piece hood can reduce the repair cost by two-thirds: “These trucks do get bumped into. Things happen. Headlights get knocked out. If there is an accident, we can make repairs instead of getting the whole hood replaced.”
Stationary grille
He said if the hood does not need to come up, International offers a stationary grille. It's necessary when front-mounted equipment impedes tilting of the hood.
“If there's a plow harness up front, can it be tipped forward?” he said. “If there's a rail for sewer-type or tanker-type equipment, does that rail need to come up away from the chassis? You need to make it easy for customers to access the engine compartment.”
Engine hardware options include engine brakes, exhaust brakes, powder-coated heated oil pan (“which helps reduce corrosion, especially if you're using magnesium chloride”), top-mounted filters, and long-life coolant. Engine programmable options include road speed limit, engine shutdown, oil-change indicator, water in fuel sensor, and fuel filter change light.
“If you're an owner-operator and have a fleet of trucks, do you want your guys going 65 mph or 80 mph? You can regulate the speed of those chassis.”
On the fuel filter, he said: “It's only as good as the last good clean tank of fuel you have. If it lasts 25,000 or 50,000 miles — whatever the rated performance of that filter is — if you put in a brand new filter and get a bad load of fuel, that filter is trash and you have to replace it.”
He listed the factors that affect the powertrain: configuration (6×4, 4×2, etc), GVW and GCWR, mission (startability, gradeability, geared speed, cruise speed, and altitude), component compatibility, and resale considerations.
“Is this going to be a 6×4? 4×2? 6×6? Are you going to need all-wheel drive capability? What grade are you going to be pulling? What GVWR do you need? As you move up in GVWR, it requires a different transmission because you have more torque being delivered by the engine into the transmission. If the transmission can't handle the torque, it can't do the work.”
The rear axle concerns are capacity, rear-axle ratio, lift axle, bridge formula tags, and pusher strings.
“Is this a bridge formula truck?” he said. “Am I going to have a stinger axle on the back or a pusher? Is it going to have tags? Will it be pulling a huge grade for the rest of its life or is it pretty much on flat roads?”
Rear suspensions
LePage said rear suspension types are walking beam, spring, air, torque rod, axle spacing, and auxiliary suspension.
“Where are you going to mount your body?” he said. “Will it be used on road or off road? Will air suspension give you a better ride? Do you need air suspension to maintain the integrity of your load? Do you have fragile product, or is it just salt and gravel, so you need a good stiff suspension that will live in a harsh environment.”
He said there are many fuel tanks, including steel, aluminum, powder-coated steel, D-type, and split/combination (hydraulic in one section, diesel fuel in the other). Shallow tanks are for extra ground clearance, while deep tanks are for additional capacity.
“What's the duty cycle of this chassis?” he said. “Can it make one shift without coming back in for fuel? That'll be the determing factor whether I need 80 gallons, 100 gallons, or 50 gallons.”
He said wheel options include cast, hub piloted, steel, powder-coated steel, aluminum, and extra-thick discs. Tire options include region haul, severe duty, long haul, and on/off highway.
On extra-thick discs, he said: “We're finding with the side blade or a snowplow that there is a lot of side loading that happens to the rim. We are recommending you use a thicker rim for those types of applications.”