Knowledge Base
S·O·S Wear Rate Analysis
Prevent problems and reduce costs by knowing wear rates
Wear rate analysis is an integral part of the Finning (Canada) fluid analysis program that helps you
maintain equipment performance and maximize availability. Through regularly scheduled
testing of oil samples from your engine, hydraulics and powertrain systems, wear rate
analysis detects metal particles caused by component wear. By monitoring trends in
the type and quantity of particles, you can get early warning of problems before major
damage occurs.
Understanding wear metals
Every oil-washed systemengines, hydraulics, transmissions, and final drives
produces wear metals in everyday operation. If wear accelerates, the concentration of wear
metal particles increases, signaling a problem. Wear rate analysis allows you to find
problems before they result in major repairs or machine failure.
Wear rate analysis can detect particles that range up to about 5 to 8 microns in size. Wear
metal concentrations are expressed in parts-per-million (or ppm). The Finning (Canada) fluid analysis
program tests for the following wear metals: copper, iron, chromium, lead, tin,
aluminum, molybdenum, silver, nickel and titanium. Most of these wear metals are found in
machines and engines. Certain elements in a sample may be from the oil additive
package rather than from wear within the system. Skilled dealer interpreters can tell the
difference between normal elements and those that indicate abnormal wear. Oil additive elements typically are calcium, magnesium, zinc, boron and barium. Phosphorus, vanadium and sulfur are present naturally in crude oils. Sulfur is present naturally in some fuels and sulfur compounds are sometimes added as anti-corrosion agents in gear lubricants and as anti-oxidants in lubricating oil. Phosphorus can be present as an antiwear additive in some lubricants.
Contaminant elements like sodium and potassium can indicate coolant contamination, silicon normally accompanied with aluminum, dirt entry.
Silicon/aluminum ratio in dirt varies by location
The primary constituents of dirt are minerals containing silicon and aluminum. The ratio of these two elements varies widely from place to place. Clay soils contain nearly as much aluminum as silicon. This is one reason why local interpretation of your sample results is important. We are familiar with the soils in your area, giving us the best understanding of the combinations of elements in your samples.
Trending wear metals in your equipment
Two identical machines under identical conditions may generate wear particles at
different rates. Our Fluid Analysis interpreters have access to a large database of samples for
comparison with samples from your equipment. However, your own machines provide the best
guidelines for appropriate levels of wear metals in each compartment and thats why
trending is an essential part of wear rate analysis. After three samples have been taken
from a particular compartment, a trend for each wear metal is established. Our
interpreters then compare subsequent samples to this trend line to quickly spot deviations
as well as monitor gradual changes in concentration levels. This attention to trends also
assists with life cycle analysis, helping you optimize productivity.
The technology behind Wear Rate Analysis
We use an emission spectrometer (ICP) to perform wear rate (elemental) analysis. The spectrometer
determines wear elements and silicon in a sample by subjecting the oil to very high
temperatures. At these temperatures, the elements in the sample are atomized,
with each emitting a different wavelength of light energy. An optical system measures and
records the light energy and calculates the results in parts-per-million (ppm) for each element.
How much is a ppm? Take one aspirin, crush into powder, divide into 225 equal parts, drop one part into a liter of liquid and you now have a ppm.
Combinations of Classic Wear Elements
ENGINES-TOP END
| Primary Element |
Secondary Element |
Potential Wear |
Probable Problem Area/Causes |
| Silicon (dirt) |
Iron, Chrome, Aluminum |
Liners, Rings, Pistons |
Air Induction System/Filter Dirt Contamination |
| Iron |
Chrome, Aluminum |
Liners, Rings, Pistons |
Abnormal Operating Temps., Oil Degradation, Fuel and/or Coolant
Contamination, Stuck/Broken Rings |
| Chrome |
Molybdenum, Aluminum |
Rings, Pistons |
Blowby, Oil Consumption, Oil Degradation |
| Iron |
-- |
Liners, Gears, Valve Train, Crankshaft |
Abnormal Operating Temps., Lack of Lubrication, Contamination, Storage
(Rust) |
ENGINES-BOTTOM END
| Primary Element |
Secondary Element |
Potential Wear |
Probable Problem Area/Causes |
| Silicon (Dirt) |
Lead, Aluminum |
Bearings |
Dirt Contamination |
| Lead |
Aluminum |
Bearings |
Lack of Lubrication, Coolant Contamination, Fuel Contamination |
HYDRAULICS
| Primary Element |
Secondary Element |
Potential Wear |
Probable Problem Area/Causes |
| Silicon (Dirt) |
Molybdenum, Aluminum |
Cylinders, Rods |
Dirt Contamination |
| Copper |
Iron |
Hydraulic Pumps |
Oil Degradation, Contamination |
TRANSMISSIONS
| Primary Element |
Secondary Element |
Potential Wear |
Probable Problem Area/Causes |
| Aluminum |
Iron, Copper |
Torque Converter |
Oil Degradation, Lack of Lubrication, Contamination |
| Copper |
Iron |
Sintered Bronze Disk |
Oil Degradation, Lack of Lubrication, Contamination |
FINAL DRIVES
| Primary Element |
Secondary Element |
Potential Wear |
Probable Problem Area/Causes |
| Silicon (Dirt) |
Iron, Aluminum |
Gears |
Dirt Contamination, Clay Soils Contamination |
| Iron |
Sodium, Chrome |
Gears, Bearings |
Water Entry, Preload Loss |
Pinpointing the causes and effects of component wear
By comparing infrared (oil condition) test results with wear metal buildup, we can
pinpoint probable causes of elevated wear metals. The chart above illustrates some of the
most common wear metals, their source(s), and the potential problems they indicate in
oil-lubricated systems.
Spectrometry can detect dirt contamination, as well as wear metals. Silicon is the most
common element indicating dirt entry, although some clay soils also produce increased
aluminum readings.
Monitoring your components
When Finning (Canada) fluid analysis identifies an increase in the concentration of one or more
metals, it can point to the wearing component most likely causing the increase and, often,
the probable cause. For example, a sudden increase in copper and iron in a hydraulic oil
sample would probably indicate a problem with the hydraulic pump caused by either oil
degradation or contamination (see chart, above).
Silicon/aluminum ratio in dirt varies by location
The primary constituents of dirt are minerals containing silicon and aluminum. The
ratio of these two elements varies widely from place to place. Clay soils contain nearly
as much aluminum as silicon. This is one reason why local interpretation of your sample
results is important. We are familiar with the soils in your area, giving us the best
understanding of the combinations of elements in your samples.