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Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Mon Dec 13, 2021 2:37 pm
by KiwiME
A couple of us Kona owners have been working over the last two months to rectify a choice by Hyundai to not provide basic ferrous particle filtration in the gear reducer, or what everyone knows as a magnetic drain plug. All the Hyundai/Kia cars I've listed in the subject line I believe use the same family of gearboxes or even the exact same model as the Kona. It's a splash-lubricated 2-stage parallel shaft single-speed reducer with helical gears - that happens to be identical to the type used in the Nissan Leaf, hence the post in this forum. It runs a 70W/75W GL-4 such as Redline MT-LV, rather than an ATF.

Due to this inexplicable omission steel particles shed during break-in and from ongoing wear continually circulate among the gears and bearings until they have been ground down to a fine dust. This makes the oil look black like black coffee. For those not aware, rolling element bearings deteriorate faster when ingesting steel particles. Gears are less fussy but it's never a good thing.

So, our earliest oil change was done at 3,700 km and it was black with silver particles. We have reports of perhaps six more oil changes up to perhaps 80,000 km, and of course all were pitch black.

The simplest and cheapest preventative measure any owner can take is get ONE oil change ASAP before the callout in the maintenance schedule, typically 120,000 km. That will reduce the rate of ongoing wear from that point on and may lessen the chances of a failure outside of warranty. As many of us Kona/Niro owners know, there have been many gearbox noise complaints and a couple of documented catastrophic failures where the output shaft (diff) tapered-rollers fail.

The ideal situation is to install a magnetic drain plug (or 2 as used in the Leaf) when the car is new so that break-in particles can be sequestered up-front. Once these particles are ground down they have less affinity for the magnet and the damage has already been done. We are testing an aftermarket plug with a glued magnetic but I'd be cautious about recommending this one until I've had a few months more experience. There are others, some with a crimped-in magnet (like the Leaf) but they need to be short, not sticking out like on the Leaf. The thread is M18x1.5 and the thread length is 12mm. You could have 3mm more for the magnet to stick out. The washer is soft aluminium, 1.5 or 2mm thick.

We also have two oil analyses but there's nothing unexpected except the high aluminium and silicon levels, much as seen in the Leaf Blackstone reports posted elsewhere. The aluminium is a concern because of where that could come from, the primary and intermediate shaft bearing retaining diameters.

I'm an M.E. and have some industrial gearbox experience from long ago. I'm quite aware that these gear reducers can survive with oil in a deteriorated state but I'm puzzled that Hyundai/Kia would have taken such a risk when every other EV manufacturer seems to have done it right.

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Thu Jan 27, 2022 3:01 pm
by voltamps
Good post. I saw your https://bobistheoilguy.com/forums/threa ... ls.348730/ too.

Yes, most of that silicon element you see is anti-foam, very important. Some of it might be from some ground-up gasket material, no problem. (In engines, high silicon is a sign sand dust is getting in past the air filter area, yet a gearbox like a Kona or Leaf probably doesn't have that issue.)

The Kona EV 70W GL-4 has about the same viscosity as the Nissan Matic S ATF fluid in the Leaf. The much higher levels of anti-wear phosphorus in the 70W GL-4 stuff makes it a better oil to use than the Matic S brew with low levels of anti-wear chemicals. I'll probably get the 70W GL-4 fluid into my Leaf eventually.

My Leaf's (22 SV+) original fluid is in there now, at only 500 miles so far. First I'll put in Valvoline Maxlife ATF, the right viscosity, and with twice the phosphorus as Matic S. After a few thousand miles more I'll probably change it to the Kona EV 70W GL-4 or maybe try Redline MT-LV with the much higher anti-wear levels.

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Thu Jan 27, 2022 8:21 pm
by cwerdna
Interesting to know... if all goes according to plan, I'll be a leasing a Niro EV from a dealer in So Cal (via an auto broker) this weekend then driving it back to Nor Cal. I probably won't purchase at lease end but if I ever buy a used HyunKia EV, I guess I'd want to gets its gearbox oil changed pronto.

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Tue Feb 01, 2022 9:08 am
by voltamps
I just changed the almost-new (518 miles) '22 SV+ Leaf fluid out, and it is kinda surprising. Gears like this don't typically get the surface roughness already polished down completely at the parts factory. It "wears in", while in service, and we hope the magnets catch most of it. .... I ran across an Eaton co. patent the other day ( https://patents.google.com/patent/DE60130835T2/en ) which said the Ra (RMS peaks/valleys asperities roughness) should be between about 3 microinches to 10, ideally.

I can't figure out why Kia/Hyundai doesn't put in factory-installed magnets either. It does seem to help a lot. Cascading wear due to loose iron particles just keep grinding down the gear teeth & bearings. Tesla puts a magnet & even an oil filter on many of their later models to really get the most life and also to prevent warranty claims.

I put in Valvoline Maxlife ATF (kv100 5.9 cSt) for now, and will change it again a few months from now for it's final fill of Redline (mostly PAO/POE) MT-LV 70W GL-4 which includes a lot of phosphorus anti-wear chemicals in a proven formula for non-hypoid racing & street gear sets such as manual transmissions, DCT's, AMT's, transfer cases, etc.

Image

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Tue Feb 01, 2022 10:04 am
by OldManCan
Thanks for sharing the photos and your findings. I am sorry for being a little slow but can't decipher if the photos are looking good or bad. Can you kindly comment on this? Did you find more or less particles on the magnets compared to what you expected to see? Thank you

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Tue Feb 01, 2022 1:31 pm
by voltamps
It is more iron goop than I expected. With only 518 miles, I wasn't sure how they would look. It is probably par for the course though.

Turns out experts like Molakule on bobistheoilguy.com and a few other sources are probably right when they say you should change out the fluid at 500 miles when new to get out the initial break-in junk. .... If you want extra life out of the gears, bearings, and differential in there.

As far as the lack of magnets in a Kia-Hyundai gearbox, its strange since most engineers use magnets for these in other makes. For example, the Chevy Bolt has an internal magnet inside. Most ICE vehicle auto trannies have a sump magnet.

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Tue Feb 01, 2022 2:41 pm
by Nubo
Maybe Kia use an internal magnet somewhere in the case, deeming it sufficient for the life of the vehicle?

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Tue Feb 01, 2022 3:11 pm
by voltamps
Nubo good point. The way Kiwi_ME and others refer to the "black coffee" colored fluid after some miles, it makes one think nothing is in there cleaning up at least a portion of the iron particles.

For Kia-Hyundai EVs, I noticed a magnetic drain plug can be had from Porsche cars, Miatas, probably others, in the right size for those Korean EVs. ... M18x1.5 and 12 mm long plugs for differentials and manual trannies are out there.
https://www.autohausaz.com/pn/10607
https://drainplugmagnets.com/thread_type/metric/ I've used Dimple for ICE engine sumps, very powerful magnet.

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Tue Feb 01, 2022 6:11 pm
by shark
I had a chance to see a soul gear box disassembled. There was a magnet installed internally. About 1 cm by 3 or 4 cm by 2.5 cm?
A little pocket cast in the bottom of the housing. Magnet slides in. When the other half of the housing is assembled, the magnet can't get out. Looking at that housing. I don't think a magnetic drain or fill plug would help. Drain and fill plug both at least 2 inches buried down a hole. No oil flow at all.

Re: Kona, Niro, (original) Ioniq and Soul will benefit from a gear oil change

Posted: Wed Feb 02, 2022 10:23 am
by voltamps
OK, the Soul Magnet (sounds like a good rock band name...) is like what the Bolt does, a magnet tucked away. Drain & fill pllug magnets would still collect more Fe particles since all the flow nearby would settle fresh fluid in there after driving around a while, slowly gathering at least something over the life.