UOA for Hyundai Kona Electric, high aluminium and silicon levels

[Kiwi_ME]

Just to close off this thread for those interested, I recently discovered that the most likely reason for the black oil and high iron/aluminium UOA levels is that the gearbox internal magnet is loosely captive in the aluminium housing directly under the stream of oil off the final drive gear. It's clearly spinning and rattling, wearing both the aluminium housing and scraping off any particles it happened to catch. Internal magnets must be rigidly held due to the severe turbulence in the oil circulation happening in a small gear reducer. Nisson got it right with the Leaf.

I note that the Ioniq 5 / EV6 has a similar arrangement but also adds a filtered and pumped oil system to cool the electric motor. If that magnet has the same issue that filter could clog with shed particles over time.

Aside from what I found in the video, the near-absence of particle accumulation on a non-serviceable magnet after 24,000 km is good evidence of this theory. I've glued some neodymium magnets to the outside in an attempt to bias the internal magnet away from the "nib" that it's rubbing against.

In 2,000-4,000 km I'll check the oil again and see if it's clear this time.

 

[Kiwi_ME]

Eleven months later with the external magnets in place as mentioned above, my latest gear oil change has come out clean confirming what I thought was happening. The loose factory magnet is collecting fresh particles then shedding them again as it spins and rattles under the influence of oil streaming off the final drive gear. The oil ends up being full of break-in particles that are no longer magnetic.

A stack of external magnets on the gear casing exterior is able to contain that motion enough to minimise the problem.

Once ball and roller bearing are damaged by ingesting steel particles, their lifetime will certainly be stunted. No wonder so many owners have had to have the gear reducer replaced, the vast majority fortunately under warranty. The few owners that have repaired their own have only needed to replace the bearings.

Hyundai, that's a rookie mistake to not secure a particle magnet placed in a high oil flow region and shame on you for not correcting it after all these years (since 2017 on the Ioniq EV).

Owners of Kona and Niro EVs globally have been sending me UOA reports and they all over the map. The vast majority of the (16) first oil changes are far higher than they should be. The lab notes, in addition to the usual horoscope-type wording generally indicate "elevated levels" particularly with regards to aluminium, not surprising since there are no intentional aluminium wear surfaces.