Here's some testing I carried out to complement testing done by others over on HyundaiKonaForum.com :
Testing Magnetic plug options for the Kona EV gearbox in water
I installed and sealed each of three magnetic plug options into their own 400 ml clear plastic container such that only their top surfaces were exposed to the interior, as they would be when installed in the aluminium-cased Kona gearbox. Those plugs tested are the DeFill M18 with neodymium magnetic, the Toyota OEM 70-series Landcruiser diff plug with ceramic magnetic, and the home-brew solution - three Ø18x3mm neodymium disc magnets attached to the outer surface of the Hyundai OEM steel plug. I’d consider the DeFill to be similar enough to the Votex DP007 to perform the same, but the DeFill is 3mm longer but since it hasn’t been tested in the Kona I can’t specifically recommend it as an alternative to the Votex.
The agitator is an 18mm spade drill and the target agitation speed is 1500 RPM. One container lid was drilled to fit the spade drill shaft so water doesn’t splash out when agitating.
The iron filings were made with mild steel on a slow-turning drill-mounted grinding wheel to avoid overheating the particles and damaging their ferromagnetic properties. I filtered the particles magnetically to remove non-ferrous debris and divided them up about equally for the three plugs I’m testing, each quantity I’d describe as about what I’d expect to see as normal wear in the Kona’s gearbox over perhaps 50,000 km.
One downside of using water as the fluid medium instead of oil is that the particles rust in about 30 minutes so the entire experiment must be performed and disassembled expeditiously to keep the plugs in good condition. The upside is that the video images are clearer, there’s less risk of a nasty mess if something leaks, and the final cleanup is much easier.
The experimental method was to fill each container with water, install under the drill press and add the particles and allow them time to find their happy place. I quickly found out however that if dropped in gradually nothing much happens until agitation is started, but in two of the three cases the particles clumped together when dropped in and subsequently find the plug immediately.
In all three plug tests I replaced the water after the initial agitation to clear out any remaining non-ferrous debris. The contents were agitated for about a minute then allowed to settle before being agitated again to see if any break loose. The video is edited to minimise boredom, so intervals appear to be shorter. The top agitation speed generates tiny air bubbles that should be not confused as being significant loose ferrous particles. There is some inevitable foreign debris floating around as well.
The important outcome for all three options is that no amount of agitation could visibly knock any particles loose and all options work acceptably well. I'll note that in reality actual wear particles may have been subject to intense heat and as a result may have lost some ferromagnetic attraction, so this test is carried out with ideal particle properties.
