Repair issues and fixes

I'm not getting much either and what's there is very fine.

A fourth reported oil change, this one from Germany, Google-translated:

That's the third unprompted mention that the car now runs quieter.

 

Interesting. I cannot detect any change in noise levels in mine. If there is any it is masked by road noise. Maybe I should turn up my hearing aids, LOL!!

 

Thought there's no mention of it in the owners manual, is it possible that the gross discolouration in mine at 4000km could be due to an additive like molybdenum disulphide or a graphite treatment? I guess the analysis will tell.

 

That question came up on Reddit but the owner carried out the change anyway. I suppose it is possible but on the other hand there's no call out in the specification. Even if that was the source of the blackness it's the evidence of ferrous dust that concerns me. Particles of any type are detrimental to oil lubrication because of the cavitation issue I'd mentioned earlier, at least in my experience and understanding.

Here's the conversation:



I have popped a message on the FB Niro group (see one response below) and at SpeakEV. I don't know if I have the stomach to face even more skeptical owners of the Soul and Ioniq on all their forums, which also use this gearbox.

 

Their loss to suffer. To mangle an old saying
"There are none so deaf as those who refuse to listen."

 

Ive got about 3500kms on my 2022 in Canada, I'm going to book a reduction fluid change asap. Did you do it at the dealer or an independent shop?

 

I did mine myself.

Look back a few pages to see what you need to do. You need a level surface, ramps x 2, trolley jack x 2, safety stands x 2, 24mm socket wrench, torque wrench, flat blade screwdriver, 10mm wrench (socket and electric drive not necessary but make it easier), suitable small funnel, tube (about 600mm length) to plug onto the funnel and fit into the 16mm fill hole. 1 litre of transmission fluid (grade specified in the owners manual).

If you're up to DIY or an independent shop, I strongly recommend you buy a magnetic drain plug - details in previous pages - and have the mechanic or yourself replace the OEM plug with that. Preferably buy two and replace the filler plug as well. Belts and braces. If you buy the one KiwiME and I bought, you will need a 17mm socket to torque it up.

And when you get it done, could you please post some pics of the fluid in a bottle and also in a tray of some sort so we can get an idea of its condition. (Ask your mechanic to keep the sample uncontaminated - maybe give him/her a clean 1 litre bottle.)

 

Thats' a me..!!

 

I have to apologise to Hobbit. You don't miss much and that should have made me think more before replying.

I kinda dismissed your suggestion that there could be non-ferrous particles in there, but having re-read the thread and seen (again) KiwiME's post #137 on P7, I realise what you were probably referring to and I now agree - there could well be non ferrous material in the oil, though I sincerely hope not. If all that stuff is aluminium from a bearing rotating in its housing then I don't hold much hope for a bright future for my reduction assembly. The oil analysis I'm waiting for will presumably tell all.

 

Here's pics of the oil in my MY19 at 17500kms. What lead me to check was both the milling noise that was apparent in the passenger floor at low speed and the video from The Offroading Mechanic on YT. Also noted was the looseness in the CV shaft...

I reported it to my selling dealer at service. They responded saying it's normal. Clearly they didn't check jack. I got the sample and booked again this time with a sample pot in hand. 6 weeks later I get a reduction box replaced.

But it wasn't the end of this story. 100kms after picking the car up it dumped out the gearbox oil spraying it on the battery underside and belly pan. It didn't empty out the reduction box and it was the seal on the filler plug. Yeah righto.

 

It's encouraging to see that I've reached at least one owner after spending many hours trying to spread the word on forums and social media. If any more show up I'll begin to feel like Mother Teresa...

So, there have been two other incidents of a tapered-roller failure reported in the past, one on FB from Poland and one on YouTube from Russia. The prior report developed over just a few days and ended with a catastrophic failure on a motorway. In the second event the mechanic on YouTube blamed a defective bearing. To be honest I really doubt that was the reason, bearings are manufactured to extremely high standards.

It's really hard to predict a root cause. There a few reasons that come to mind:
1) It could be a loss of preload; a tapered roller pair requires enough preload (squeezing them together) to avoid mistracking of the rolling action when under radial loading. A loss of tracking will quickly cause damage. Acquiring a sufficient and reliable preload in a vertically-split housing I expect would not be easy at a volume production level because it requires shiming and checking. Also it's questionable IMO if the rigidity of the aluminium housing is sufficient in the required direction, unlike a cast iron or aluminum differential housing which is naturally rigid because of the round shape. The Nissan Leaf and Chevy Bolt avoid all this by using heavy radial ball bearings, a good move IMO.

2) It could be that metallic debris clogged a raceway and the rollers started skipping.

It's somewhat feasible to check for looseness from under the car but that must not be confused with normal play between the axle spline and differential carrier. Any looseness in the actual tapered roller pair is a death sentence for the reducer. It must be absolutely zero.

This is why changing drain/fill plug materials and sealing methods makes me nervous. The soft aluminium washer torqued to spec is important.
Oh, and I really appreciate you taking the time to tell your story.

 

I have only owned 3 ICE cars (Plymouth Fury, VW Diesel, Geo Prism). They all had transmission pan dipsticks.

 

I've booked an appt for Dec 28 (can't do it sooner as will be in Maui just before) to get my gearbox oil changed at the dealer. Price will be $89.95 which I thought was reasonable. They didn't have it listed as a service item, but said they would just charge the same as a differential oil change. Didn't like the idea of having to jack up the car and crawl under it, so happy to have them do it. I will ask them to save some oil in jar so I can have a look at it.

Thanks to KiwiME for making us aware of this.

 

While fielding on-going questions on FB I've discovered that Hyundai make a magnetic drain plug for the DCT (dual clutch transmission for ICE) that looks identical to the original non-magnetic plugs in the Kona. The dealer's parts department told me nothing more than it's "not a part carried by Hyundai NZ." Pretty typical service, no effort made to cross reference the number or explain why they wouldn't stock spare drain plugs. Can be bought off Amazon for NZ$52 however.

Yes, I did quickly check to confirm that the plug I removed a few days ago is not magnetic!

 

On 28th Nov I wrote the attached PDF to Hyundai Aust Customer Care. Thanks to KiwiME for allowing me to use most of his words.

Today I received the following reply:

Customer Care (Hyundai Customer Care)
Dec 3, 2021, 10:07 AM GMT+11
Hi xxx
Thank you for contacting Hyundai Customer Care.
We are sorry to hear of your recent experience and regret the inconvenience caused.
Hyundai Motor Company Australia takes all complaints seriously and we have documented your feedback against case number XXXXXXX.
We have forwarded your correspondence to the Product planning team and technical team at HMCA for discussion.
In the meantime, please do not hesitate to contact us if you require any further assistance.
Thank you.
Kind regards,
XXXX
Customer Care Officer
Hyundai Motor Company Australia
http://customercare.hyundai.com.au
Phone: 1800 186 306​

So, I have a case number and I will follow up to see what the outcome of the internal discussion is.

 

I've been reading online articles regarding industrial gearbox lubrication and filtering (Some links and salient points are below.) The science and technology is impressive for a field that I expect the vast majority of people are completely unaware even exists. This is a field that some mechanical engineers enter into and live and breath for years. I'm not entirely disappointed that I missed that path, but I have encountered many gearboxes over the years and even got asked to head the final commissioning a major helicopter gearbox test facility in the UK in 1982.

But meanwhile, the conclusion I'm slowly reaching with the Kona gear reducer (noting that the term 'gearbox' is the normal catch-all term used in the industry) is that wear particle filtration is nil, completely non-existent. That was a regrettable design move and it's no surprise that a random number of owners experience problems.

Because there is no filtration provided, wear particles from gears are being broken down to micron level by repeated ingestion into ball and roller bearings, which in turn oxidises the oil, making it look black. The resulting bearing damage may or may not be sufficient to cause noticeable issues during the service life of the car, it's just a matter of luck. But this is damage that didn't have to happen to precision machinery owners paid good money for, trusting that Hyundai would have designed this correctly.

The number one action every owner can take as a preventative measure is to get an oil change as soon as practical. Just one will markedly reduce the risk of a noticeable problem in the long term, especially if it's done early on, my guess under 5,000 km. A diligent owner might consider further changes every 2 years. But even later on, an oil change will effectively slow down the ongoing damage that would otherwise continue unabated.

Addition of a magnetic drain plug, considered to be the most basic form of magnetic particle filtration from an industrial perspective, is most useful from the new while break-in particles are still large enough (>100um) to stick to it. Once any remaining particles break down to micron levels, apparently they are less effective, and that's where periodic oil changes come into play. I'd conservatively suggest that owners get the oil changed and don't worry yet about the magnetic drain plug until myself and OzKona have some experience with their reliability. I would hate to recommend something I haven't thoroughly vetted, and that's experience talking.


Machinery Lubrication Magazine

The Rationale For Using Magnetic Particle Collectors
"Years of experience from the user community have provided ample evidence and motivation to deploy magnetic separators and detectors wherever possible."

Magnetic Filtration Applications and Benefits
Role of Magnetic Filters
Car owners, car mechanics, equipment operators, maintenance technicians and reliability engineers know the importance of clean oil in achieving machine reliability. Tribologists and used oil analysts are also aware that in some machines as much as 90 percent of all particles suspended in the oil can be ferromagnetic (iron or steel particles).
Magnetic Plug
The most basic type of magnetic filter is a drain plug (Figure 2), where a magnet in the shape of a disc or cylinder is attached to its inside surface (typically by adhesion). Periodically, the magnetic plug is removed and inspected for ferromagnetic particles, which are then wiped from the plug.


Figure 2. Drain Plug Filter

Today, such plugs are commonly used in engine oil pans, gearboxes and occasionally in hydraulic reservoirs.

5 Lubrication Myths That Are Costing You Money
"Myth #1: OEM Hardware is Satisfactory
OEM hardware accessories, including small vent-plug breathers, dipsticks and non-metallic drain plugs, are doing your equipment more harm than good. When in pursuit of lubrication excellence and world-class maintenance, you should consider removing these devices and outfitting your equipment with proper contamination control devices such as desiccant or hybrid breathers, minimess sampling valves, magnetic drain plugs, quick connectors, vented sight glasses, bottom sediment and water bowls (BS&W), etc."​

Magnetic Plug Inspection Enhances Condition-Based Maintenance
(more as an example of how the magnetic debris off drain plugs is analysed in amazing detail)​

Best Practices for Analyzing Gear Failures
Was the Oil Degraded?
The oil might lose its ability to lubricate if its viscosity changes significantly or if it is oxidized. ... Contamination by water and wear debris accelerates oxidation. The following symptoms are indicative of oxidation:

• A foul odor (sour, pungent or acrid smell)
• A dark color
• An increase in viscosity
• An increase in the acid number
• A shift in the infrared spectrum
  

Basic Wear Modes in Lubricated Systems
Abrasive Wear
Abrasive wear is estimated to be the most common form of wear in lubricated machinery. Particle contamination and roughened surfaces cause cutting and damage to a mating surface that is in relative motion to the first.
Three-body abrasion occurs when a relatively hard contaminant (particle of dirt or wear debris) of roughly the same size as the dynamic clearances (oil film thickness) becomes imbedded in one metal surface and is squeezed between the two surfaces, which are in relative motion. When the particle size is greater than the fluid film thickness, scratching, ploughing or gouging can occur. This creates parallel furrows in the direction of motion, like rough sanding. Mild abrasion by fine particles may cause polishing with a satiny, matte or lapped-in appearance. This can be prevented with improved filtration, flushing and sealing out small particles.​

 

I just received my oil analysis (post #192). They needed to know what make/model, Vin and oil type so they could cross reference their own documentation. I gave them all that, plus the oil type straight out of the owners manual, plus the pics I have posted here in earlier pages. They seem to have missed the significance of EV because they refer a couple of times to ATF and torque converter wear.

For those who can interpret, it is attached. KiwiME?

Covering note from consultant:

I don't think it's 70W as its more like ATF fluid. The Hyundai and Shell ( Viva Energy ) guide says the same.
[Possibly they've looked up data for an ICE model]

Iron elevated possible sources include gears, bearings & spacers Aluminum elevated. Aluminum can be a component of dirt ingress & can indicate torque converter wear. Silicon elevated. Check seals & breathers for dirt ingress. Visible wear debris evident (see filtergram).

The grey fine wear you are seeing in ferrous and may be run-in or the early signs of a problem. New cars tend not to have the oils changed to remove run-in wear. This is very common. This may be run-in wear. Drain \ flush to remove built up debris. Monitor trend at next oil sample. (My bolding)​

Report summary from technician:

Iron elevated possible sources include gears, bearings & spacers Aluminum elevated. Aluminum
can be a component of dirt ingress & can indicate torque converter wear. Silicon elevated.
Check seals & breathers for dirt ingress. Visible wear debris evident (see filtergram). This may
be run-in wear. Drain \ flush to remove built up debris. Monitor trend at next oil sample.​

The car has done about 200km since the oil change. I am going to treat that as the above mentioned flush and do a second change immediately. The next one after that will be in approx 6000km at 10k on the odo.

I will also send this report to Hyundai.