There’s more to an oil change than simply draining the fluid
March 27, 2019
Oil changes remain a vital part of any truck maintenance program.
The operation has evolved in many ways, the most obvious probably being the oil drain intervals associated with advances in refining and additives chemistry.
“Before, we just ran the standard 1540 and we were doing our oil changes at about 20,000 miles [32,000 km]. Now we’re doing them at 40,000, 42,000 miles [64,000 to 67,000 km] and we could probably extend that further,” says Darryl Watkins, maintenance manager for Commercial Transport, a fleet of 21 power units headquartered in Lively, Ont.
Semi- and fully synthetic oils have allowed extended intervals that are now approaching 100,000 km, according to Michel Forest, who manages the maintenance of 50 trucks for Keystone Western, from Ile Des Chenes near Winnipeg.
“Our Peterbilts are based at 96,000 km. Paccar, with the new MX engines, have extended the oil drains significantly. Because of the aftertreatment and some of the filters they use, they don’t collect as much carbon into the oil now,” Forest says, adding that the intervals are at 80,000 km for his Western Stars and 56,000 km for the Volvos. He rightfully insists on the importance of complying with engine manufacturers’ recommendations with regards to oil change intervals, though.
One size does not fit all
Regardless of the truck brand, the application and environment in which the power units are operated can make a major difference in engine oil lifecycles, Watkins advises. Some of his trucks based in Timmins, Ont., are drained at intervals measured in time – 950 hours – instead of distance because a typical haul is barely over 20 km – but in difficult conditions, including carrying mine tailings. “These trucks never shut down,” he says. “Lots of dust, lots of rough terrain, lots of contamination,” he adds, also referring to filters having a difficult life in such conditions.
The all-Kenworth fleet’s other units that run on more-conventional routes are drained at a little more than 60,000 km.
Dirt in all forms and the related potential for oil overheating is also a concern at Keystone Western, where trucks are fitted with bug screens to help keep radiators clean, Forest explains. “Our maintenance program is pretty rigid. When we look at our trucks when they come for servicing, we look at the radiators and make sure that they are clean. If we find that a radiator is dirty, we will wash it out, thus keeping the engine temperature at a better pace where it’s not gonna get overheated, which in return will cause the oil to get cool because oil coolers on the engine depend on how well the cooling system works,” he says.
Driving habits can also be an element that contributes to oil needing to be changed sooner than expected. Not surprisingly, both our interviewed maintenance managers rely on automated transmissions to remove human factors from the equation.
“If our trucks were all standard shift transmissions, that would probably change some of the aspects of the oil drain intervals. But all our company trucks are automated transmissions. It shifts at the right intervals and RPM. We are guided by what the transmissions do, so we know that they’re not gonna be over-revving,” Forest says.
Optimize, don’t jeopardize
Once you remove the drain plug, engine oil will take somewhere between 15 and 40 minutes to completely come out of the engine, depending on its temperature. This time period allows the technicians to perform other verification tasks while the truck is in the shop, optimizing each minute of scheduled downtime.
Keystone’s maintenance manager uses the TMT Fleet Maintenance software package and says his team has worked to program it with every possible scenario, to coordinate oil changes with other routine work such as checking the batteries, wiring, lighting, etc. At Commercial Transport, Watkins stresses: “With our regular oil change, we check the driveline, check the universal, check our wet line, hydraulics, PTOs, etc.”
“We try to capture as much as we can when we bring a unit into the shop. Let’ say I bring a truck in and we’re doing an oil change on it and I see that a filter is at 90% for the interval, then we will definitely do it at the same time, minimizing the downtime of that unit. It doesn’t have to come back just to get a filter changed or inspected,” Forest says.
Keystone has dedicated trucks, but those come with additional challenges, as oil changes need to be scheduled in accordance with drivers’ hours of service. A decal is put inside each truck, indicating when the next full-service is due.
“We depend a lot on the drivers that they keep track of their mileage and they will phone in and tell us that the truck is coming,” Forest indicates. “Then we minimize the amount of time that the truck is gonna be down and make sure it also meets his e-log obligations,” he adds. “We work fairly closely with the drivers and also dispatch to try to organize everything, to orchestrate it so that everything flows.”
Both fleets have an in-house maintenance team but still allow oil changes to be conducted out of premises when needed. “If the truck is at Kenworth for a fault code or something and is due for an oil change and it’s gonna be down for a few days waiting for parts, we’ll have them do it [the oil change],” Watkins explains.
The situation is similar at Keystone. “We don’t want to jeopardize any engine warranty or prolong oil change intervals just to get the truck back to our shop. We want to make sure that our equipment is running up and down the road and making us money,” Forest says, referring to the occasional oil drain at a dealership.
Watch, touch, smell, document
Just like oil analyses, simple actions such as watching, touching and smelling the oil that comes out of the pan can tell a lot about the condition of an engine.
“When you pull a drain plug, check for filings, things like that. Antifreeze or diesel in the oil, texture,” says Watkins.
Oil with a greyish color could be a sign that coolant is leaking in it, indicating that a gasket may be failing. A fuel smell in the oil could reveal faulty injector cups, while excessive dilution identified through the sense of touch could be the result of overheating.
Driver input can also be valuable if someone notices an oil pressure drop and relays that information to the maintenance crew for investigation.
Last but not least, to keep all warranties in effect, document the moment when each oil change is made and take note of anything unusual.
As an example, in addition to keeping these records in his computer system, Watkins even has oil samples filed.
“It’s very important to keep track of your information,” Forest agrees, adding that engine manufacturers want to have the information readily available to them, should an issue arise. “If you can’t provide that due diligence, then you’re gonna be in trouble at one point or another,” he says.