Repair issues and fixes

No doubt you've done the eBay thing, but FWIW I found https://tinyurl.com/this-on-eBay. It is short with a flush magnet so I don't think it will protrude into the mechanicals, but I don't know how the magnet is secured into the plug.

There are others on the same page with magnet protrusions of varying lengths. One of the shorter ones might be ok.

Could you install it and test for fouling by lifting the front end and having two people rotate the front wheels forward or backward in unison to rotate the whole gear train including the reduction gear, thereby testing for unwanted contact with the gear train?

 

I guess I am kind of shocked by some of this. The gearbox issue was starting to become a worry for me, but then the battery issue came up and the Kona was no longer my concern.

Another thought is the differential thermal expansion of different metals like aluminum and steel. So you might have a situation where the bearing was secure at some temperatures, and start spinning at others. As it happens, aluminum expands at about twice the rate of steel, so I could see that problems might be worse in warm weather, and seem to ok go away in cool weather.

 

Yeah, if I remove the oil again I'd be able to determine what clearance is available. Wish I'd thought of that at the time but I didn't notice how dark the oil was until I'd finished the job and poured the old oil into a clear bottle.
I'm very wary of the machined aluminium plugs on eBay because the magnet is likely only glued in. OEM plugs tend to be made of mild steel with a crimped-in magnet so it's mechanically secured.

I was a bit depressed about this as well 2 days ago but now I've convinced myself that it's plausible that the discolouration is entirely due to ferrous debris, meaning that it isn't an early indication of the knocking issue. The fact that my gearbox has still endured the completely unnecessary wear from grinding normal ferrous sheddings into dust due to an apparent oversight on Hyundai's part doesn't sit well however. But, it's encouraging that many Konas have high kms with no apparent issues. IMO, all Kona Electrics will have blackened oil by 20,000 km because they have failed to include a magnetic drain plug. Apparently the DCT transmissions in the ICE Konas have a similar issue.
I don't think differential thermal expansion plays a role in the issue I've outlined here, but it may if the knocking appears.

 

I've ordered this drain plug despite not knowing if it will be too long. It's not cheap and will take 2-3 weeks or two to get here. I'll have to carry out the oil change process again but all the info so far indicates that this will solve the blackening problem.

The Chevy Bolt has an awesome gearbox design. It has a huge internal magnet and an oil pump because the motor is cooled with gearbox oil.



Gee, only $21.70 for a crush washer. Lol, the most expensive plug I found was US$1,000 for a Porsche.

 

AUD$37.26 incl GST and shipping to Sydney for me. The price for the crush washers is for a pack of 20

My car is only 6 months old, 5 year warranty. Do you think they'll get snarky when they see it at the first service in May next year?

EDIT: I just checked the maintenance schedule. They won't see the plug next year. Probably never will unless during a 60k inspection they drain the fluid, which I very much doubt. I bet they just inspect the level, if they do even that. And our useage is low - the car will be out of calendar warranty before 60k and then the problem won't exist.

EDIT # 2: Thanks Kiwi for your research and heads-up on the issue. Now to buy some fluid, ready for the plug when it arrives.

 

On a whim, I emailed Hyundai Mobis in SK with this question and a photo of the black oil:

 

KiwiME,
May I pick your mech engineering brains?
Given that

1. it is normal for gear trains to shed a bit of material, and
2. presumably more of that occurs early in the life of the vehicle (ie the first few thousand km) as it runs in, and
3. that there is no magnetic pick-up in the Kona EV,

do you think that on these vehicles it would be wise to do an early fluid change to get the initial debris out of the system at, say, 3000 or 5000km?
Or do you think that would be overkill?

I intend to follow the fluid change with installation of a magnetic drain plug.

My thinking is to get rid of as much of the initial uncaptured debris as early as possible and catch the later, presumably finer sheddings with the magnetic plug.

TIA

 

Definitely not overkill and you could use this oil (pic below) as an alternative to Redline. You'll need slightly more than 1 L (the Redline bottle is 0.95 L) so the Penrite 2.5 L bottle is a better choice anyway.
Had I known then what I know now I'd have changed it at around 1,000 and every 5,000 km subsequent, at least until I could correct the magnet deficiency.

 

Thank you. My Kona is at 3000km now. I've already ordered 2 quart bottles of Redline MT-LV so when both that and the plug get here I will do the first change.

 

Just a reminder that I’m not certain yet if the magnetic plug nose will clear the internals. I think it will but it will need testing. I figure I could always use 2 washers if needed. This plug was the highest quality I could find on Amazon.

 

Thanks. Likewise re the plug. I was looking at your pic of the plugs in the other thread. The driven gear (crownwheel?) would have to run very close to the bottom of the housing for the plug to foul - which I admit is possible in order to get oil carried up to the driving gear. I think there is a better than 50% chance of success. But given my luck with games of chance .... The only lottery I ever won was the National Service draw in 1968.

First thing after draining the fluid would be to stick a finger in there, or if a pinkie won't fit, a borescope. I have a cheapie that will do the trick. Failing that, anything would do really, just probe around to establish the clearance.

Mirror and torch maybe?

 

As I was thinking about the difficulty I would soon face needing to spin the gears while the car is elevated on ramps to properly check the drain plug clearance, I thought I'd do more investigation. This is what I found.

The filler and drain plugs are visible in this image from the Russian teardown video and the end of each plug appears to be recessed about 2mm from the inside face. Also you can see that the two plugs appear to be on the same plane. But, the drain looks to be at a larger radius away from the bearing centre. The next snap shows that the drain opening is indeed about half way into the housing inner radius, as you'd expect for an effective fluid drain.

A horizontal cross-sectional rendering of the gearbox from Hyundai happens to cut through part of the filler plug thread, making it look smaller than 18mm across. Assuming the rendering is dimensionally accurate, it shows a generous clearance (yellow arrows) between the inner wall near the radius to the side of the crown wheel.

In the next image it's clear that the part of the crown wheel nearest the end of the drain plug is relatively smooth (no bolt heads,) so it won't be necessary to spin the crown wheel while it's elevated to test that the clearance is constant while it turns.

Aside from not destroying the gearbox, it's good to have lots of clearance around the magnet so that oil "windage" is less likely to strip particles off.

 

This is looking promising. It looks as though the only thing beyond the drain hole is the face of the crownwheel and that would be easily verifiable visually either by mirror and light or inspection camera. It looks sufficiently far away to accommodate the slightly protruding magnet of the new plug, again easily verifiable with a vernier depth gauge.

 

Out of interest I asked Mishimoto how they fastened the magnet into their alloy plug and received this reply just now:

Thanks for your email and for your interest in our parts.

The drain plugs use a press-fit supplemented with high-temp adhesive inside the machined end of the aluminum drain plug to hold the magnet in place. Unfortunately, we do not currently offer a low-profile version of the magnetic component, and our current design has a magnet that extends approximately 10mm from the end of the thread.

This has since been overtaken by the decision to buy the SS plug with a short magnet. (Posts 144 and 146.)

 

That's good to know. I think the aluminium-type plugs are not ideal for durability in any case although that brand seems to be reputable.
I'm not aware of the length dimensions of the Votex plug as I assume that the photo is generic. They stopped answering my questions when I responded to their "how many cylinders" inquiry accurately. But it's seems there's plenty of room in any case.

I'm going to filter and reuse the Redline oil I installed 40 km ago when I swap out to the new plug. A kitchen strainer and a coffee filter should do the job overnight.

Meanwhile the fact that there are perhaps 120,000 Kona EVs out there running around with ever-blackening oil is a bit depressing. I commented on one of John Cadogan's YouTube videos ("Auto Expert John Cadogan") that he should do a video on this subject, since he's an engineer as well, has been driving a Kona EV and does not mince his words.

 

It would be nice to hear/see a response from Hyundai or even a dealer about this.

 

Yes, 40km old oil is a bit too new to be tossing out at AUD$28 a litre. You know you can use a wick-and-siphon method to filter oil - it is very effective but I've forgotten how long it might take to filter a litre or so of oil.

By the time my plug arrives Kona will have about 4000km on it so I will be tossing the oil.

I have just finished watching his Kona videos. He certainly has a style of his own This reduction gear issue would be right up his alley.

BTW I ended up with the Penrite 70W/75. My on-line supplier of Redline found they had none, couldn't get any until Feb next year and gave me a refund. Thanks for the Penrite tip.

 

My magnetic drain plug arrived today, way earlier than I'd expected. It does look exactly like the photo. 12mm of thread and the supplied washer is 2mm thick leaving 10mm engagement. I'd prefer it to be longer but it does seem to closely match the length of the existing plug.
The hex is 17mm instead of 24.
Hope to get started on the job soon!