2019 Kona EV Motor Noise Issue

The reduction fluid oil replacement cost 112.42+tax:
75W85 Fluid - $35
Env Charge - $7.44
Labour - $69.95

 

I wonder if they used a 75W85 because it was the thinnest GL-4 they had readily available? The spec for the Kona is 70W, which has a viscosity similar to ATF.

In the owner's manual it's stated as "70W, API GL-4, TCGO-9(MS517-14)." The latter "MS" spec is 75W according to Google. Redline has a MT-LV 70W/75W which seems ideal for DIY. Further searching revealed that Redline recommend it as well.

My Kona is out of all warranties now except the 10-y battery part, so it's in my best interest to check the cleanliness myself.

Ah, it seems the dealers might stock this for ICE manuals and/or DSG:

 

Brought it to the dealer this week. They confirmed the noise on acceleration but couldn't reproduce it when the car was lifted up. They said that since it only happens on load they are thinking it may be something with the reduction gears. Sent info to Hyundai and they are waiting for a response...said it could be a few days so hopefully more info late next week.

Sent from my SM-G960W using Tapatalk

 

I procured the appropriate Redline MT-LV replacement oil for the gearbox and decided to change it today at 3 years and merely 19,000 km. Here's a video of the oil being drained and then poured into a container. The latter half is edited to a reduced framerate to make it easier to see that the fluid is free of metal debris, despite being darker than I would have expected.

 

Spec says 1 litre but 1 quart (946 ml) of oil was sufficient while the car was on ramps but I think I'll lift the rear with floor jacks tomorrow to level it better and try to add a bit more. You fill through the filler plug until it overflows like any diff or transfer case.

The plugs are a 24mm hex and have aluminium washers. A socket and 1/2" ratchet drive do the job nicely.

The Redline MT-LV is very thin, just like the original oil. No doubt anything thicker would reduce efficiency. I suspect the gearbox interior has a magnet as there was no magnet on the drain plug and I'd have expected some minor metallic debris, yet there was none.

 

Just as an aside, where do you get that little measuring cup dispenser? I could use one of those for other applications.

 

How on Earth is your undercarriage so clean?!

 

It's a large syringe with the plunger removed. An auto parts shop should stock that.

The drivetrain was cleaner than I thought it would be but the top surface of the plastic cover not so much. But what surprised me is that there's a low-tone horn down there. The high-tone one is located next to the heat pump valves, up top. I wonder why they're in two different places?

 

Ahh, yeah, thought the shape looked familiar. Thanks, attaching that hose outlet helps to get into tight and awkward locations.

 

The reason I used this method instead of a pump from underneath is that the 1 qt oil container was slightly less than the 1 litre gearbox capacity and I couldn't afford to lose any. However, as it goes I still spilled more than I should have.

 

Now that it's almost done I'll add that this job can't be easily done with ramps as I have used. The angle is too great to get the gearbox oil level high enough because the filler opening is at at the far-rear end. I ended up jacking the car up at the rear to nearly the same level as the front, where it took another 150 ml.

The closest option might be to just jack the left side of the car up, but it's clear that using a lift is really a far better method.

 

Thinking about this while I cleaned and reassembled the underside panels, I’ve decided that the cleanliness of the oil is unacceptable for the low kms, only 19,000. I even wondered if it was due to an electrical discharge.
Carefully watching the disassembly video posted last year, I can see that there is no magnet installed in the sump. But there is a carbon brush at the motor output shaft to ground any stray currents.
So, I’m concluding that it’s the most obvious reason.
Splash-lubricated gearboxes should always have a magnet secured somewhere to collect ferrous debris shed from the gears, otherwise it continuously accompanies the oil as it does its job. The gears don’t care but rolling element bearings will suffer completely unnecessary wear.
This is why the oil is dark and there are no slivers of steel present- they’ve been ground up to particles so small that they stay suspended in the oil. I was able to pull some out with a magnet however, so I’m convinced that my conclusion is correct. The should still be golden brown at so few kms, with visible slivers of steel stuck to a magnet.
Whether this is problematic within the service life of the Kona is hard to predict but I’ll be changing the oil about every 20-30 thousand kms from now on.

 

I thought after watching your video but before reading following posts that the oil appeared to be holding stuff in suspension, so I agree with your analysis.

Given your info above (thank you very much) do you think that another DIYer could drill the drain plug and insert a suitably sized magnet - perhaps a light press or interference fit aided with brass shimstock if necessary?

 

Well, I do have university training in gearbox design, although have never specifically used it.
It’s clearly a major risk placing anything inside a gearbox and aftermarket magnetic drain plugs need careful vetting. It’s an 18mm thread but I failed to measure the pitch and length, never mind if there’s clearance for a magnet on the end.

 

Thanks KiwiME

 

So a few days after my service where they replaced the reduction fluid, the noise on acceleration disappeared . It's now been a couple of weeks and it has not come back. Not sure if it could have been due to dirty reduction fluid (after 2.5 years/19k km) that was replaced...I noticed it disappeared after probably 10-20km of driving.

 

Was that service done under warranty?

 

No, it was part of the 30 month service. I had received a doc from the dealership that included the intervals below:

 

I'd be surprised if only an oil change could have reduced or eliminated the noise but you could be lucky. This is what mine looked like after 3 years 19,000 km and I didn't have any noise. There is nothing unexpected here given that Hyundai have not bothered to include the all-important magnet to collect ferrous debris.