I've been reading online articles regarding industrial gearbox lubrication and filtering (Some links and salient points are below.) The science and technology is impressive for a field that I expect the vast majority of people are completely unaware even exists. This is a field that some mechanical engineers enter into and live and breath for years. I'm not entirely disappointed that I missed that path, but I have encountered many gearboxes over the years and even got asked to head the final commissioning a major helicopter gearbox test facility in the UK in 1982.
But meanwhile, the conclusion I'm slowly reaching with the Kona gear reducer (noting that the term 'gearbox' is the normal catch-all term used in the industry) is that wear particle filtration is nil,
completely non-existent. That was a regrettable design move and it's no surprise that a random number of owners experience problems.
Because there is no filtration provided, wear particles from gears are being broken down to micron level by repeated ingestion into ball and roller bearings, which in turn oxidises the oil, making it look black. The resulting bearing damage may or may not be sufficient to cause noticeable issues during the service life of the car, it's just a matter of luck. But this is damage that
didn't have to happen to precision machinery owners paid good money for, trusting that Hyundai would have designed this correctly.
The
number one action every owner can take as a preventative measure is to
get an oil change as soon as practical. Just one will markedly reduce the risk of a noticeable problem in the long term, especially if it's done early on, my guess under 5,000 km. A diligent owner might consider further changes every 2 years. But even later on, an oil change will effectively slow down the ongoing damage that would otherwise continue unabated.
Addition of a magnetic drain plug, considered to be the most basic form of magnetic particle filtration from an industrial perspective, is most useful from the new while break-in particles are still large enough (>100um) to stick to it. Once any remaining particles break down to micron levels, apparently they are less effective, and that's where periodic oil changes come into play. I'd conservatively suggest that owners get the oil changed and don't worry yet about the magnetic drain plug until myself and OzKona have some experience with their reliability. I would hate to recommend something I haven't thoroughly vetted, and that's experience talking.
Machinery Lubrication Magazine
The Rationale For Using Magnetic Particle Collectors
"Years of experience from the user community have provided ample evidence and motivation to
deploy magnetic separators and detectors wherever possible."
Magnetic Filtration Applications and Benefits
Role of Magnetic Filters
Car owners, car mechanics, equipment operators, maintenance technicians and reliability engineers know the importance of clean oil in achieving machine reliability. Tribologists and used oil analysts are also aware that in some machines as much as 90 percent of all particles suspended in the oil can be ferromagnetic (iron or steel particles).
Magnetic Plug
The most basic type of magnetic filter is a drain plug (Figure 2), where a magnet in the shape of a disc or cylinder is attached to its inside surface (typically by adhesion). Periodically, the magnetic plug is removed and inspected for ferromagnetic particles, which are then wiped from the plug.
Figure 2. Drain Plug Filter
Today, such plugs are commonly used in engine oil pans, gearboxes and occasionally in hydraulic reservoirs.
5 Lubrication Myths That Are Costing You Money
"Myth #1: OEM Hardware is Satisfactory
OEM hardware accessories, including small vent-plug breathers, dipsticks and
non-metallic drain plugs,
are doing your equipment more harm than good. When in pursuit of lubrication excellence and world-class maintenance,
you should consider removing these devices and outfitting your equipment with proper contamination control devices such as desiccant or hybrid breathers, minimess sampling valves,
magnetic drain plugs, quick connectors, vented sight glasses, bottom sediment and water bowls (BS&W), etc."
Best Practices for Analyzing Gear Failures
Was the Oil Degraded?
The oil might
lose its ability to lubricate if its viscosity changes significantly or
if it is oxidized. ...
Contamination by water and wear debris accelerates oxidation. The following symptoms are indicative of oxidation:
- A foul odor (sour, pungent or acrid smell)
- A dark color
- An increase in viscosity
- An increase in the acid number
- A shift in the infrared spectrum
Basic Wear Modes in Lubricated Systems
Abrasive Wear
Abrasive wear is estimated to be the most common form of wear in lubricated machinery. Particle contamination and roughened surfaces cause cutting and damage to a mating surface that is in relative motion to the first.
Three-body abrasion occurs
when a relatively hard contaminant (particle of dirt or wear debris) of roughly the same size as the dynamic clearances (oil film thickness)
becomes imbedded in one metal surface and is squeezed between the two surfaces, which are in relative motion. When the particle size is greater than the fluid film thickness, scratching, ploughing or gouging can occur. This creates parallel furrows in the direction of motion, like rough sanding. Mild abrasion by fine particles may cause polishing with a satiny, matte or lapped-in appearance.
This can be prevented with improved filtration, flushing and sealing out small particles.
