Mike Laird, a field service engineer with International, tells the story of a driver who became inattentive and drove off the road, running into a pond by the time he woke up. He then had the truck towed to a dealer and said there was water in the engine because it had rained heavily the night before.
Laird also knows of a driver who tried going across a drawbridge as it was opening. He bent his truck’s frame.
Another driver was pulling a Caterpillar D-9 bulldozer across a field on a lowboy and got stuck in the mud. Seeing another D-9 sitting nearby, he decided to pull the truck out of the mud with what was available, rather than calling a tow truck. The dozer exerted so much pulling power. That result was a front bumper and hood pulled off the frame.
And then there was the guy who, finding a leak in his power steering system, elected to improvise with a bit of engine cooling system stop-leak. The result was a $3,000 bill for a major power steering system rebuild.
These stories fortunately represent the extremes of driver operational and maintenance error. However, much more mundane truck abuse occurs every day. Victor Chavez, southwest regional maintenance manager for Rush Truck Leasing, believes there are lots of things drivers just don’t know about maintenance and operation. “Those who know about them can greatly improve the viability of a trucking business,” he says.
Here are 10 tips on chassisfriendly operation:
1. Stick with the sticker
Many fleets use a sticker on the windshield to remind the driver when maintenance is due. Many drivers want to keep that pretty truck the fleet has given them looking sharp, and will remove it. Leave the sticker in place and get the truck in when maintenance is due.
2. Do the walk-around
Rush’s largest trouble area is tires. And while actually gauging them is best, Chavez believes a driver with a sharp ear does OK during his daily checks by beating on a tire and listening to the sound. When the tire’s low it sounds different. Low pressure from even a small leak quickly destroys a tire’s ability to support a load, causing it to overheat and fail. Noticing that a tire is low, or that a wheel seal leaks, will often save many hours waiting for repairs while on the road. Tire checks and a general look around every time you stop while on the road (or at least every 300 miles) are also valuable. Problems often develop in 300 miles.
It’s even better when you notice such problems after a run and report it in a clear way to the repair shop so the truck can be repaired while it’s down anyway.
3. Avoid powertrain problems
Chavez says it’s really important to be careful about drivetrain abuse these days because they’ve changed. Driveshafts used to be the system’s relatively inexpensive safety valve that would fail. It’s now the differential ring gear or axle inside the drive axle assembly that fails, and such repairs are expensive. When loaded and pulling out of a grade-level loading dock, don’t touch the throttle. The governor will feed plenty of fuel to the engine to do the job – if you’re in the right gear.
Alan Hertzog, director of dealer and customer training for Mack and Volvo, says this is a critical point because of ceramic clutches. They’re “aggressive” and grab hard. This reduces clutch wear, but can throw a lot of strain into the rest of the drivetrain. Don’t be afraid to release the clutch gradually and make it slip just a little. “Clutches are cheaper than transmissions and axles,” says Hertzog.
Use a gear low enough to allow an easy start – the lowest gear in the box when climbing out of that low dock with a load. That will minimize both clutch wear and drivetrain strain.
Chris Fair, from Kenworth Truck Company’s warranty department, culled some suggestions from several KW experts. Their driveline pet peeve is sliding the fifth wheel with a loaded trailer that has its brakes applied. Clutch engagement torque is so high, this can be worse than popping the clutch. Give the gentlest tug you can, then get out and look at the lock mechanism to see if it has properly latched.
You can beat up the truck one day, and have it fail weeks later. This failure began as a small crack after a driveline shock. It then spread gradually with the shaft finally failing much later in the area where the metal looks grainy.
4. Avoid destructive idling
Both the Kenworth experts and Hertzog think prolonged low-speed idle is one of the worst engine abuses. Kenworth says, “After starting a cold engine and when oil pressure is stable, gradually raise idle to 1,000 or 1,100 rpm for approximately five minutes until coolant temperature has been raised to at least 110 degrees. Better yet, plug the truck in overnight.”
Hertzog points out, “Technically, the engine will never warm up at low idle. The best way to warm it is to drive it. At idle, without turbo pressure, fuel will saturate the cylinder walls. Fuel is not as good a lube for pistons and liners as 15W-40 engine oil.” Assuming you don’t have to blast right out onto the interstate, his recommendation is to bring the oil pressure and air brake system pressure to maximum, then start driving gently. Don’t sit there at 600 rpm for half an hour.
Hertzog adds that there is a good time for idling: That’s after a hard run, for all of three minutes. Mack has done tests and found this is not only vital to cool the turbo with oil flow, but brings the heads and block to a more uniform temperature before shutdown, increasing head gasket life.
Both Kenworth’s experts and Hertzog also mentioned those long periods of idling even after the engine is hot. “Avoid prolonged idling if at all possible. If idling is necessary, it should be at fast idle [900-1,000 rpm],” say the KW people.
5. Watch engine rpm
Kenworth’s experts also caution, “Try to avoid really excessive lugging involving periods of more than five minutes at full throttle more than 100 rpm below the torque peak.” In other
A slightly delayed failure. Some of the teeth on this small-diameter gear were torn at the initial shock. The broken pieces of metal then caused further chips and gouges in the gears as pieces got caught in the spaces between the remaining teeth.
words, you don’t have to downshift for a short grade, but you should when fighting a long hill. Engine oil flow and cooling improve greatly at higher rpm. Mike Laird mentioned the need to watch for excessive rpm, especially when riding down a long hill in a lower gear. Engine revs past the governed speed can quickly damage the camshaft and related parts.
6. Easy on the ether
Hertzog cautioned against using manually sprayed ether for cold starts, which can cause detonation and 4,000-degree temperatures in the cylinder. Modern combustion systems with electronic injection timing, along with better batteries and starters, will produce 1,200-degree temperatures in the cylinder and start the engine at very low outside temperatures. Hertzog has seen many truckers shatter the top compression ring with the detonation caused by tons of ether. After that, the engine still runs, but compression drops enough (producing only 800 degrees) that it then needs ether to start on every cold morning, “like an alcoholic,” Hertzog says. If you need ether for cold starts, install an automatic ether metering system that protects the engine.
7. Watch transmission temperature
Transmissions generate a lot of heat, so keeping an eye on their temperature is a critical item for drivers. With any transmission, the greatest heat is generated at lower speeds under heavy loads, as when climbing steep grades. Fluids exposed to too high a temperature get thin, break down and can’t protect parts. Metals also become softer at high heat. Keeping transmission fluid within its approved temperature range will prolong both fluid and gearbox life.
As far as manuals and automated manuals go, Eaton Fuller says the trans oil should run 120 degrees above whatever the outside temperature is – say 210 degrees on a 90-degree day. Fuller transmissions should not routinely see temperatures over 250 degrees, or 300 degrees for short periods. Meritor transmissions should not reach more than 275 degrees, even for short periods. To cool the transmission, just stop the truck and idle in neutral. If you reach the top of a steep grade and the road levels off, the transmission should cool nicely on its own. If it’s running hot under highway cruise conditions, there’s something wrong with the cooler. Stop and check it out.
8. Don’t overheat automatics
Although some automatics are nearly foolproof, drivers can still help keep the transmissions out of the shop. With torque-converter-type transmissions, hard low-speed pulling is far more likely to lead to overheating if the unit is running in torque converter mode (in the first two gears below the lockup speed). With these automatics, heating may also occur when shifts are very frequent.
Allisons should not run above a 250-degree maximum continuous operating temperature. Maximum intermittent temperature is 300 degrees. When a transmission has a retarder, 300 degrees is considered a fairly normal occurrence, but when a transmission achieves such a reading under pulling conditions, it’s a sign something may not be right, says Dan Murphy, Allison Transmissions service manager, 1000-2000 Series.
He recommends you carefully read the owner’s manual for temperature recommendations because temperature sensors are installed at various locations. The temperature will normally read about 50 degrees higher if it’s measuring converter-out temperature than if it’s giving you sump temperature. Just watch for any indication 20 degrees above normal. If the transmissions gets overheated, it may be quickly cooled by putting it in neutral and running the engine at fast idle.
But Nick Bond, vice president and general manager of Russ Moore Transmissions of Fort Wayne, Ind., a major Allison transmission remanufacturer, says a very long idle time while sitting still can cause transmission overheating, especially when the road surface may be hot from the sun.
Traditional hydraulically controlled automatics can easily be abused if the driver revs the engine and then engages drive or reverse, or if the driver hits drive while rolling backward or reverse while rolling forward. Put the unit in gear only when the engine is at idle speed and the truck is stopped.
Murphy recommends dropping an Allison back to a lower gear if traffic or terrain conditions are causing it to hunt back and forth between gears. For example, if the transmission is hunting between third and fourth, put it in third. This will prevent high wear per mile in expressway or city traffic.
Bond recommends avoiding use of the selector to set shift points during normal acceleration. The transmission is designed to minimize clutch wear and shift shock when choosing its own shift speeds by balancing torque output and clutch operating pressures.
9. Wash corrosives off the cab
Kenworth recommends watching out for magnesium chloride and sodium chloride, frequently used out West to de-ice roads. These do a job on aluminum wheels and bumpers via corrosion. Flush with water as soon as you can after driving over surfaces treated with this stuff.
10. Routine maintenance is vital
Routine maintenance is the most important key to keeping a trucking on the road. Hertzog suggests that the air dryer be serviced by replacing desiccant and internal filters, if applicable, right at recommended intervals. This helps so much because it’s not practical to clean moisture and dirt out of brake system components – many are not even designed to be disassembled.
Don’t just change engine oil and filters. Make sure to add SCAs to the antifreeze as necessary. Laird mentions that this means testing for the protection level with a lithium strip. Even extended-life antifreeze needs the additive package at 150,000 miles, so monitor your mileage.
Change the power steering fluid and filters once a year in over-the-road trucks, and twice a year in off-road vehicles. The fluid’s anti-foam and corrosion agents frequently break down, softening seals and making them leak. Laird knows of one trucking company that replaced a power steering gear only to find a clogged filter was responsible for poor steering performance.
Laird suggests finding a section of parking lot without any puddles of fluid to park your rig on when stopping. Then, after a meal or half an hour making phone calls, get down and examine the pavement under the truck thoroughly for leaks, with a flashlight if necessary. Look for leaks from the radiator, coolant hoses, transmission and axles. “Components are getting to be pretty expensive,” he says. But when full of the right fluid, their life is extended. Also check for wheel seal leaks at this time.
Laird also thinks it’s smart to make sure the truck gets into a dealer or the fleet shop for a thorough inspection of its braking system at the normal maintenance interval. “DOT will do it if you don’t.” And he makes a valuable recommendation about the owner’s manual: Read it, and follow OEM recommendations when it comes to lubrication intervals, rather than picking your own. This way, your warranty is protected if a part fails prematurely. If extending oil change intervals, do it scientifically with oil analysis, and then consult with all the parties involved to be sure your engine and warranty will both be safe.
As a driver, you can do your fleet and yourself a favor by operating the truck in a way that’ll cut down on breakdowns and repairs. This comes back to benefit you by keeping you on the road, making more money.