New electric and alternative-fuel trucks, using oil analysis

March-April 2020

Paul Abelson


Q: You’re always writing about old technology, like engines, fuel and transmissions. There’s a new generation of trucks with electric motors and natural gas. You should write about them.

A: A very good point from an observant member. There are several reasons. First, this is a maintenance column. Land Line has outstanding writers – John Bendel, Tom Berg and others – who cover future trends. My role is to answer questions about maintaining the equipment our fellow OOIDA members have now.

New technologies are being pioneered by large fleets, not owner-operators or small fleets. A large fleet can afford to have a few trucks down from time to time to develop long-term advances. Small operations can’t. When the manufacturers develop these new products to the point they are feasible for the rest of us, their common problems will be discussed at groups like the Technology and Maintenance Council. When ownership of these trucks becomes common, we will report their maintenance issues to you.

Natural gas-fueled trucks, similar to the diesels we operate, are still largely confined to large fleets. If and when ownership becomes common among our membership, we will answer questions as they come in.

Currently, the new technologies involve safety devices operating on 12-volt systems, but powertrains operate at 240, 480 and even higher voltages. Unless you have special training on these high voltages, they can be quite dangerous. Shocks at 12 volts can be annoying. At 480 volts, they can be fatal. Maintenance should be left to factory-trained pros. As for the low-voltage safety devices, we’ve written previously about maintaining wiring and connections and preventing corrosion. If circuits are good, problems most likely are due to the internals of the “black boxes,” microprocessors and controllers, not items you should attempt to repair. That maintenance should be left to factory-trained personnel.

If you are a true do-it-yourselfer and insist on working on your own truck to whatever extent your skills allow, remember that even the most advanced propulsion systems will still need wheels and tires, axles, bearings and brakes. All will have safety lighting required by Federal Motor Vehicle Safety Standards 108, mirrors specified by FMVSS 111 (unless that changes), and a host of mechanical devices needed for safety and performance.

Even without the new technology, there will be old-fashioned maintenance to discuss.

Q: I have a 2011 Mack straight dump truck. I’m leased to a small local fleet, and I usually make about five to eight runs a day to local construction sites. They’re mostly 20 to 25 miles each way, with occasional runs as long as 100 miles, but those are rare. After reading your articles, I started having oil analysis done whenever my truck is serviced, about 18,000 to 20,000 miles. Our fleet has all of its company-owned trucks serviced at our local Mack dealer, and he gives us the same prices as the fleet gets. So far, every oil analysis has come back as good. I’d like to extend my oil changes so I can get more days on the road. What do I have to look at to do that?

A: Any day on the road is far better than a day in the shop, so I commend your efforts. Yes, oil analysis will predict when you will need to service your truck if you take the time to analyze and plot your reports. They also will let you know when parts are starting to wear so you won’t be caught out on the road with a sudden failure.

Analysis labs examine your results several ways. First, they have limits for wear metals, acid and base levels, contamination and viscosity. For example, if your engine’s wear limit for iron is 100 parts per million, any reading below that is considered good, whether in the 20 ppm or the 80 ppm ranges. The same applies to external contaminants like silicon, a major component of the dirt from your construction sites. If you look at just one report at a time, you may see 30 ppm silicon and think the oil is good. At that point, it probably is, based on wear limits.

That’s when trend analysis comes in.

It’s easy to detect trends in engines if you use the spreadsheet features in your computer’s Microsoft Office program. Set columns for the miles when each sample was taken, and rows for the element measured. Fill in the values reported for each element. Set a different color for each element to avoid confusion. The resulting graphs will highlight any changes from trends that require further investigation.

If the wear limit for iron is 100 ppm, we say that any reading below that will be “good.” But if readings have been 21, 23, 25, 23 and 26 ppm but then go to 38 ppm and then 52 ppm, trend analysis will flag the latter readings as outside the trend. They are still within limits, but they show that something is causing increasing wear inside the engine. It may be a cam lobe that is not being properly lubricated or a cylinder wall that is being scraped by a broken compression ring. The camshaft will not have other elements increasing, while the liner also will have increased chromium. Trend analysis can help head-off problems before they cause failures.

The total base number measures reserve alkalinity, which is needed to counter acidity. The total acid number should never exceed the total base number. If it does, change oil immediately. Trend analysis will help predict changes.

Exceptions reporting will alert you to such things as fuel or coolant in the oil and other things that require immediate action to find their causes and get them corrected. A more comprehensive discussion of oil analysis is in TMC RP 318C. LL 

Paul Abelson, senior technical consultant, is a longtime contributor to Land Line. He’s a member of the Society of Automotive Engineers and a member of the Technology and Maintenance Council. In 1995, TMC awarded him its Silver Spark Plug award. In 2006, he received the Lifetime Achievement Award from the Truck Writers of North America. Although he’s “retired,” he still makes a popular contribution to Land Line readers with “Maintenance Q and A.”