Repair issues and fixes

hi on the 2022 module there are only too things in the wheel arch a brake pipe with brake fluid in it and the brake caliper electric check wire.
your thing looks thicker than the brake electric check wire, on your front parking system, is one of the sensors missing from its whole in the front of the car,
if so it looks like the sensor fell out when you hit the curb and then dragged on the road which caused the wire to rub through on the driveshaft, leaving what you have now, the only fix i know of is to have your dealer replace the sensor and reset the fault code in the cars computer,

 

Hi, certainly. In fact, replace that cable (speed sensor / abs sensor) has been the solution for these symtoms:

I hope this is not so serious for Kona57 since symptoms are differents.

 

well it seems that its possible that the diff center is assembled using a mineral based lub, and as the gearbox lub is fully synthetic they do not mix well, causing in some cases lubrication failure and early demise of the drop box and difff bearings, hence the odd Colour and smell.

 

The saga deepens. I asked the owner mentioned above a few questions, most importantly:
2) Was the magnet saturated with metal debris?
3) what evidence led to (your) conclusion that the bearings are of poor quality?

Here's the (translated) answer:

Assuming I've got the right end of the stick here, I have to wonder how this is possible? I've asked him for clarification.
Maybe they buy these magnets from the same vendor that makes their magnetic drain plugs?

 

KiwiME,

Did you find your old magnetic compass to try to detect the presence of a magnet?

 

No, I don't have such a compass, would have to check the $2 shops. But I did notice that my iPhone will detect a ceramic magnet when it's within 1cm of the upper left corner. The compass "heading" display goes blank, presumably due to the field being far greater than the Earth's and overwhelming the sensor.

I'll wait until the Ioniq owner I mentioned confirms no debris on the internal magnet after the failure, plus it's a bit warm the next few days to be crawling under my car outside.

 

The gearbox mystery continues on the Ioniq forum. If due to non-ferrous particles, the blackness would have to be aluminium based on our UOA results as chromium levels were very low.
I'll note that the "failure" in this case was reported as noisy bearings rather than a catastrophic mechanical breakage.



I've asked the poster about the gear wear I think I see in the photos posted:

 

I tried, using a hiking compass. I couldn't get a result worth showing here owing to the size of my compass and interference from the new magnetic drain plug which is quite close to the fixed magnet (if it is there). However with a bit of experimentation moving the compass I was able to satisfy myself that the magnet is there.

Maybe one of those small novelty keyring compasses would be better able to fit in the confined space.

 

Interesting that he isn't seeing debris. Assuming you've changed the oil since replacing the plug with magnetic one, have you seen metal debris stuck to the plug? If so, does it seem to be an abnormal amount?

 

Well, it seems there's no obvious mechanical root cause to this particular Ioniq gearbox failure in Poland. The damage to the intermediate shaft bearings mentioned below without any ferrous content on the magnet leads me to consider the rare situation of electrical discharge. It happens that the Nissan Leaf gearbox has some sort of grounding brush on the intermediate shaft, something I'll have to investigate further.
Certainly when a few of us do another oil change sometime this year the continued presence of black oil may tell the story.

 

For the record we have another Kona gearbox UOA from one of our American friends on hyundaikonaforum. At 28,000 miles (~45,000 km) iron was 205 and aluminium was 283, roughly 50% higher at three times the distance of the next closest UOA. There's nothing out of line here except that it's further confirmation that periodic oil changes are a good thing.

We also had another incident of the dealer installing the incorrect 75W-90 right here in NZ.

 

The gearbox investigation is not getting easier. I'm leaning towards stray eddy current discharge as being the root cause for some gearbox failures, in particular the case of the Ioniq mentioned above which tellingly had left no mentionable debris on the internal magnet, and reportedly suffered the most damage at the intermediate gearbox shaft bearings.

Certainly this mode of failure has been a distant thought all along but is a phenomenon that I would have expected Hyundai/Kia would be well aware of and handle appropriately. High-frequency currents in the motor windings can generate eddy currents in the rotating assembly that produce a voltage potential.

Research reveals that the issue has been common in industrial motor and gearbox applications for many years and there are vendors making mitigating solutions such as insulated bearings and ground brush assemblies. The only mitigating item I can find in the Kona is this carbon brush on the motor shaft. That's all good if it's working but a disaster if it's not.

I haven't determined if the Nissan Leaf has any grounding on the motor (it almost has to) but it certainly does on the intermediate shaft. Why there? I posted this question on a Leaf forum today but I suspect it's because the bearings and gears provide some insulation when in use by running on oil films. The intermediate shaft is intermittently "floating" while the output shaft and differential is perhaps better electrically grounded via the axles and other bearings. A voltage potential could jump the gap through the oil film and take a microscopic chunk out of a bearing raceway. Over millions of these events erosion damage to bearing raceways can eventually cause noise.

The concern with brushes is that the contact surface must be oil-free, not easy to maintain when oil or grease is close by.

 

Hmmm, would interesting to see a discussion about this with you and tear down expert Sandy Munro. Or would this be beyond his pay grade?

 

Lol, it's getting past my pay grade as well! I do enjoy watching his teardowns including the Tesla Plaid he's doing now but Sandy really should stick to sales and let his younger (and properly qualified) engineers do the analyses. He's well experienced at optimising certain production design issues but I can tell by his propensity to guess that he's never any formal training.

 

Has anyone done a fluid change since replacing the standard plug with the Votex? I'm curious if there is any metal buildup on the Votex plug, or if the internal gearbox magnets Kiwi mentioned on page 17 are doing their job.

 

If you mean "should I install a magnetic drain plug?", I'd suggest that it's not a proven advantage at our current level of understanding, but certainly can't hurt. Doing a preventative oil change is far more important.
There are still questions regarding what is going on and certainly we will know more once one of us does another oil change sometime during the year.

 

Yes, you answered my underlying concern. I'm still under warranty and would rather avoid the magnetic drain plug unless you and others have seen that it makes a marked improvement. I'll just stick with a fluid change for now and report back (2022 model).

 

For those who are using the original plug (and not a newer magnetic plug), is it fine to use the original washer or is it recommended to get new washers?

 

I had no problem reusing the original washer, torque to 35 ft-lbs.

 

I'm no auto engineer, but I think I may have found a reason as to why the Kona gear fluid gets so dirty so quickly. The Bolt, which has no issues associated with this, takes 3.1 quarts of fluid. The Kona takes a little over 1. That's a pretty astounding difference.