Kona EV: Dirty gear oil and a loose magnet, a coincidence?
Комедия
I've been working casually on this issue since November 2021. The vast majority of all 2017-2022 28/38 kWh Ioniq, 2018-2023 Kona and 2018-2022 Niro EV owners report finding the gear reducer oil black when changed, even at low miles. There have been over 100 reports from global owners on the various forums.
First on the video, we have two examples posted on FaceBook from Kona owners of what the gear oil looks like at around 4,000 km to 5,000 miles. Many others have described a similar glittery appearance. (Thanks to KZread channel "Random Technical Stuff - RTS" and Larry Melton on FB for those clips).
Recently, clean oil in my Kona installed at 20,000 km turned black by 24,000 km and so I decided to investigate with a modified endoscopic inspection camera.
As can be clearly seen, the non-serviceable factory particle magnet is installed loosely in a small cage at the bottom of the gearbox housing. The location is directly under where oil streams off the final drive gear. While driving at speed much of the one litre of 70W gear oil is being flung violently around the gearbox, which is why it's called a "splash-lubricated" design. Most EV use similar gearboxes.
The premise I'm putting forth here is that the magnet rattles and spins under the impinging oil, as any object does when impacted by a stream of fluid. Normally the magnet will attract and capture passing ferrous (iron, steel) particles, yet there is little of that to be seen despite the 24,000 km on my car.
My theory is that the particles don't stay attached due to rubbing on the aluminium parts, particularly the "rib" feature at the left which produces a scraping action whenever the spinning magnet is in contact with it, similar to a metal cutting lathe. Broken down particles will lose most or all of their ferrous attraction and therefore will re-enter the oil circulation. This is where the problems lies.
I can't overemphasise how damaging these particles are to ball and roller bearings in the long term. It's simply an unacceptable level of contamination, even for a gearbox in a motor vehicle application where only a relatively short life is required compared with industrial usage. I have no doubt that this is the root case of the infamous "wheel of fortune" noise.
The (18) first-time used-oil lab analyses provided so far (Nov 2023) by other helpful Kona and Niro EV owners show high levels of both iron and aluminium, the latter is likely to be wear material off the rib and pocket holding the magnet because there are no normal aluminium wear surfaces inside the gearbox.
I suspect the oil blackness is caused mostly by the aluminium content. Another source could be outer raceway spin happening at the input shaft, motor side. That bearing might be susceptible because the adjacent bearing in the motor shares the radial load from the pinion gear. Bearings installed with slip-fit outer raceways rely on radial loading to discourage spinning.
Unfortunately, as owners there's little we can do other than carry out more frequent oil changes in the hope that we'll get the quiet, reliable service we paid for and expect. To be pragmatic I would suggest that new owners carry out oil changes at 500 and 1,500 km (300 and 900 miles) to remove the bulk of break-in particles before the bearings have fully digested them. (EDITED Nov 2023)
The oil type and quantity is listed in the owner's manual. You can use a 70W-75 GL-4 grade which is more common such as Redline MT-LV, D-6 ATF or Liqui Moly MTF5300. The fill requirement is 1.0-1.1 litre.
Many owners have installed a secondary magnetic drain plug or placed magnets (the same round type seen in my video) on the existing plugs. We have vetted the Votex DP007 for reliability but there is also a Toyota p/n 90341-18057 that is a magnetic version of the original generic plug. Hyundai themselves offer one but several who have purchase one find it is not magnetic.
Пікірлер: 22
Thank you for your very persistent investigative work. It does look like the loose magnet is likely to be the cause of the widely reported darkened oil found at even relatively low milage/kms. Ceramic magnet materials are very hard and if this is eroding into the oil those particles will act as an abrasive. The standard oil analysis tests are unlikely to identify this abrasive material. Let's hope that after more than three years of this reported contamination problem that Hundai Motors begins to recognize it and addresses the cause.
@boredKiwi
Жыл бұрын
You've described it in a nutshell! I'm debating whether I should send my importer or the factory another email, as neither have replied to prior queries. I hope my experimental attachment of the magnets to the underside confines the internal magnet to a tighter orbit, but due to both having axisymmetric field patterns it couldn't influence the spinning. But even if it did work it could be a difficult modification to roll out among owners, many who are understandably already past comprehending the implications. Unfortunately I've noted that the Ioniq 5 (and consequently the Kia EV6) have a similar internal magnet retention arrangement. But they also have an oil filter screen and pump to cool the motor stator. On one hand the screen will catch larger particles but on the downside it could clog and reduce oil flow or damage the electric oil pump.
@vernonbrechin4207
Жыл бұрын
@@boredKiwi - Keep us informed of your attempts to alert higher-ups in the chain of command. They may not want to believe what you found, or simply rationalize it has no significant consequence. One aspect of your finding is that it is likely due to a slow mechanical erosion of the aluminum magnet pocket meaning only very small particles are scraped from the surface and then suspended in the oil before being smashed into tiny flattened aluminum flakes. I'm most worried about the small amount of surface erosion of the ceramic magnet which appears to be more of a problem than a cleaning solution. After seeing your suggestions I hope to do my first oil change at about 24,000 miles, making sure the case is well flushed, and to install the suggested magnetic drain plug. Depending on the space at that location I might glue two stacks of the rare-earth magnets where the inner magnets held onto the external magnets shown in your video. Perhaps if the pole orientations were opposite and somewhat separated then they might form a tighter 'grip' on the inner magnet. A bench test might provide you with an idea of what configuration could work best to minimize the internal magnet movements. It did look like it is a ring magnet. Perhaps someone who has an open case can supply a closeup image of the internal magnet and the travel path as seen from the outside surface of the case.
@boredKiwi
Жыл бұрын
@@vernonbrechin4207 thanks for your comments. I oriented and secured the exterior magnets to attract the internal magnet away from the nib at the left. It will be some months before I find out if this has any effect but meanwhile my impression is that the car runs more quietly than it ever has. Generally I keep a thread going on InsideEVs as KiwiME with the latest news on the subject: www.insideevsforum.com/community/index.php?threads/repair-issues-and-fixes.7097/page-31#post-186810
@boredKiwi
9 ай бұрын
@@vernonbrechin4207 I recently changed the oil again after a 3,800 km period (it was green rather than black this time) and refined the location of the stack of magnets underneath. I think it's helping but needed a stronger field so I added more for a total of 18mm dia x 15mm high. Interestingly and almost puzzlingly the car seems to run quieter now. www.insideevsforum.com/community/index.php?threads/repair-issues-and-fixes.7097/page-38#post-203245
@boredKiwi
8 ай бұрын
@@vernonbrechin4207 Another relevant update is that the Go Green Autos channel stripped an Ioniq GRU (only slightly different from the Kona) and did not see any obvious wear from the magnet moving inside its pocket. Not sure what to make of that. kzread.info/dash/bejne/f6WWzM2fqa3apqg.html
This makes perfect sense. My kia e niro is making a milling or grinding sound. This useless magnet, which cannot be cleaned when changing oil is the one that is causing trouble because it is loose and keeps banging on the casing side to side!
@boredKiwi
Ай бұрын
Unfortunately I haven't seen any evidence yet that Hyundai/Kia have resolved this on replacement gear reducers. But, a very early oil change will reveal that, somewhere around 500-1000 km or 300-800 miles. I've heard of one recently (4 weeks ago) which came out clean so there is a chance.
@quietsparks1791
Ай бұрын
@@boredKiwi for the first ever seeing a gearbox that needs magnets to clean the oil. I had a citroen and done over 200,000 miles without any issues.
@boredKiwi
Ай бұрын
@@quietsparks1791, any gearbox without a magnet is the exception rather than the rule, especially in industrial applications. Its presence may not always be obvious but it's rarely missed, even in cost-cut consumer products. And it wasn't missed in this case either, just mis-applied. Have a read: www.machinerylubrication.com/Read/794/magnetic-filtration
@quietsparks1791
Ай бұрын
@@boredKiwi very interesting. For me, the thing is to remove the reduction gear unit, drill 2 holes both sides of the magnet housing and tie the magnet to secure it. Then atleast every 20,000 miles, remove the reduction gear unit to clean the magnet. Or, remove the magnet completely and use magnetic drain plugs.
@boredKiwi
Ай бұрын
@@quietsparks1791 the latter idea would be ideal but from my experience an oil change once a year keeps the oil sufficiently clean.
I'll just add for info that the new "2023" Kia Niro EV and the upcoming new Kona EV are both ground-up redesigns and are unikey to retain this issue. They moved to oil-cooled motors like the Ioniq 5 / EV6 E-GMP EVs and so use a filter screen and pump along with a much larger quantity of oil, an ATF now.
Used oil reports: drive.google.com/file/d/18XsnmXd2WgqBwPVeOpOIlThFlAk98XYs/view?usp=drive_link Pictorial summary of oil condition: drive.google.com/file/d/1hT_rh4A95hSA6ALUEqiG--pMvxIaKxGH/view?usp=sharing
Did you leave this magnet there and use the car like that?
@paulaxford6754
Жыл бұрын
Yes, they are glued on and I'm hoping it will constrain the internal magnet to wander around less. I've only put 1,000 km on the Kona since Nov 2022 so I have a long way to reach 4,000 km so I can do an apples to apples comparison.
@thomasadmiral3401
Жыл бұрын
@@paulaxford6754 understand ,thanks
@boredKiwi
10 ай бұрын
As a note, I changed the oil 3,800 km after those magnets were fitted and there was a noticeable improvement in the oil cleanliness. I've moved the magnets slightly and added 2 more for a total of 5.
@ferixp
9 ай бұрын
@@boredKiwi Can you please post a frontal picture of the exact sweet spot for the magnets? It is difficult to judge from this angle. Even 1 mm off is a big deal. Great service to the community, very much appreciated!
@boredKiwi
9 ай бұрын
@@ferixpthe photo is at this post. www.insideevsforum.com/community/index.php?threads/repair-issues-and-fixes.7097/page-38#post-203245