Repair issues and fixes

[shorsfield]

It's not going to save your gearbox, if that's what you mean by "is it worth it".

Hi KiwiME,

Thank you for all your extensive testing and documentation over the years – it has proven invaluable as I did my research before buying a 2019 Hyundai Ioniq.

Now that I've got the vehicle (with only 25k km), I am planning to get the reduction gear oil replaced to be safe (though I understand this should have been done earlier in an ideal world, as with the Kona).

While I appreciate your investigations have been primarily targeting the Kona, am I right in confirming that I should be buying this drain plug and this Penrite oil for best performance? Hyundai wants to sell me their fluid for roughly double the price; I would happily spring for it if it was better, but I don't know if these are all much of a muchness or if the aftermarket options are actually superior. Given I've just bought the car, I'm more than happy to pay for the more expensive oil if it means a better result, but I also realize you are currently testing other viscosities and I don't want to be a guinea pig myself!

Appreciate all your help and advice!

-Simon

 

[KiwiME]

Those parts are correct. The Ioniq 38 seems to have fewer issues with gear reducers anyway. Perhaps a better place to ask maintenance questions would be the local FB group, NZ Hyundai & Kia EV's, as the content is localised.
Enjoy your new EV!

 

[shorsfield]

Those parts are correct. The Ioniq 38 seems to have fewer issues with gear reducers anyway. Perhaps a better place to ask maintenance questions would be the local FB group, NZ Hyundai & Kia EV's, as the content is localised.
Enjoy your new EV!

Just following up to say my gear reduction fluid was replaced by my mechanic yesterday, for the first time in its life, at ~26k km. As expected, it was dark and thick and desperately needed changing. I ended up going with the Redline MT-LV. He was asking (given it was serviced every year beforehand by the Hyundai dealership) why it had never been done before, and was incredulous when I explained it’s supposed to be sealed for life, and never needs replacing. It’s shocking Hyundai have never acknowledged this isn’t true.

You’re doing god’s work keeping these cars going, KiwiME, thank you.

 

[NBraz]

Is this solved on models built 2024 onwards?

 

[KiwiME]

The 2024+ model years is a 100% completely new design from the ground-up and doesn’t have all the ingredients needed for the wheel of fortune noise. I wouldn’t say it was ‘solved’, just not included.

 

[NBraz]

Hi KiwiME, thank you for all your work! Regarding the 'ingredients' for the Wheel of Fortune (WoF) noise, I was wondering if you see a significant difference in the frequency or intensity of reports between the Kia e-Niro and the Hyundai Kona (1st gen)?

While they share the same motor and GRU, some users suggest the Niro might be slightly less prone to catastrophic failure due to different torque mapping or QC standards. In your database of oil analyses and forum reports, is the e-Niro just as "at risk" as the Kona, or is there any evidence that it's a marginally safer bet for a used purchase? Thanks!

 

[KiwiME]

Comments about "torque mapping" could be confusing the 2nd-gen Niro as many had assumed it was the same underneath (when introduced in 2023) yet has significantly less specified maximum motor output torque. But not noticed is that it also has an exactly-proportionally-higher top RPM to end up with the same 150kW of power. The gearing to the the wheels was suitably shortened to maintain about 95% of the 1st-gen's acceleration.

I've not noticed any difference between 1st-gen wheel of fortune reports although at times I've felt slightly more were raised by Niro owners.

There's no technical basis for any difference as the motor and gear reducer are made in the same factories (respectively Mobis and Transys) as best as I understand. See the Transys catalog page below.

The reducer part numbers are the same, 44500-18EA1. The motor p/n is close but not identical. They range from 36500-0E700 to 36500-0E712. No one seems to know the differences.

There are already independent EV shops that can repair these in Europe (where warranties are short) and I wouldn't be surprised to eventually see refurbished powertrains being sold based on returning a repairable core.

 

[NBraz]

Hi KiwiME, many thanks for that deep dive!

Since my absolute priority is long-term mechanical reliability (keeping the car well beyond 200,000 km), I’d like to ask your expert opinion on how the Transys G1F24 compares to two other contenders I'm considering:

Chevrolet Bolt (1ET25 unit): Both Professor John Kelly (Weber Auto) and Alex (Out of Spec Renew) speak very highly of the Bolt’s drive unit (1ET25). I’ve been looking at its technical specs, and it features a "Filter Plate" to catch debris and an auxiliary fluid pump that actively sprays oil onto the motor and bearings. From your experience, does this make the Bolt’s drivetrain fundamentally superior to the "passive" lubrication/magnet setup in the Gen-1 Kona/Niro?

Tesla Model 3 (HW3 vs HW4): Does Tesla’s drivetrain (specifically the gear reducers) share any of these "particle contamination" vulnerabilities, or is their engineering on a different level of maturity? Is there a significant mechanical difference between the 2021 (HW3) and the 2024+ (HW4/Highland) units, or has it remained consistently robust?

If you had to pick a winner for "Best Engineered Drivetrain for 200k+ km" between a Bolt (1ET25), a Tesla Model 3, and the New Gen-2 Hyundai/Kia, who takes the trophy? Is the Gen-2 shift enough to beat the Bolt's active filtration? Or is there another particular model/brand I'm not aware of.