[sd_kona]

Picked up the repaired car today, two weeks after dropping off for diagnosis. They replaced the gear unit and motor bracket but not the motor. Noise is definitely better but do I still hear a faint whine? @Kiwi, is that the "Star Trek" sound that you mentioned as being normal?

Notes from the repair document:

confirmed noise coming from front end recommend install bracket kit
per tsb 22-EV-001H-1 and replace drive gear
REPAIR PERFORM REPARS AS APPROVED

36930F03 KIT INSP&REPL+REDUCTION GEAR REPL (3 TEST DRIVES)
9764 WH
1 36930-0E710-FFF BRKT ASSY-MOTOR MTG KIT B
1 44500-18EA1 GEAR DRIVE UNIT ASSY
FC:
PART#: 36930-0E710-FFF
COUNT: 1

42266 confirmed noise coming front end, replaced motor bracket and
roll stop per tsb 22-EV-001H-1 after replacement noise still heard
removed drive gear and tested drive motor with drill. passed test.
replaced drive gear per tsb 36930F03 8.80, installed motor bracket kit
and drive gear after repairs noise did not return

 

[Kiwi]

I think it's fine. That's normal gear whine and mine is the same. If the motor bearings were faulty you'd hear a far less pleasant noise.

Be sure and change the oil to avoid a repeat performance. I'd do that by 500 miles and again at 1500. Theoretically any garage with a lift can do this easy task. You'll need 2-3 US qts Redline MT-LV. The required fill is 1.05 litre. Plugs torqued to 30 lb-ft, reuse the original gaskets.

They saved you some trouble by ordering the GRU right up front because changing the bracket alone never helps and you didn't have to wait for the GRU to arrive. The TSB states the official process that must be followed for them to receive their compensation and they've done that to the letter. Plus they've 'passed' the motor with the drill test outlined in the TSB.

 

[sd_kona]

I think it's fine. That's normal gear whine and mine is the same. If the motor bearings were faulty you'd hear a far less pleasant noise.

Be sure and change the oil to avoid a repeat performance. I'd do that by 500 miles and again at 1500. Theoretically any garage with a lift can do this easy task. You'll need 2-3 US qts Redline MT-LV. The required fill is 1.05 litre. Plugs torqued to 30 lb-ft, reuse the original gaskets.

They saved you some trouble by ordering the GRU right up front because changing the bracket alone never helps and you didn't have to wait for the GRU to arrive. The TSB states the official process that must be followed for them to receive their compensation and they've done that to the letter. Plus they've 'passed' the motor with the drill test outlined in the TSB.

Great info, thanks. I was a little annoyed that it took a week to diagnose but once they did that, the parts acquisition and repair went pretty fast.

Re. changing the oil: is it 500 km or 500 miles? And why so much oil? It should 1.1 US quarts per liter, right?

 

[Kiwi]

Based on what I've heard from three other owners who have done this I'd leave it till 500 miles. Try to drive a bit more gently if possible which might avoid knocking off any large wear particles. Speed is not a big factor, just high acceleration and regen.

You'll want to carry out two oil changes. If you (or your mechanic) doesn't spill any you can get away with 1 qt each change. The added 0.1 litre can either be ignored or taken out of the old oil, or use any other gear oil. But if it's pumped in while the car is on a lift there will be some 'spillage' and that's why I've suggested buying 3 qts. At least it's less expensive in the US and off the shelf locally from a speed shop. I'd pay $60 each here and have to order it.

But, when I did a search for Redline it's not readily available in San Diego either so it might be easier to buy this Bel-ray oil which is highly reputable and shipped in litres. 75W will be fine, give them a call. It's dirt cheap as well.

 

[sd_kona]

Got it--you were allowing for two changes with 3 quarts. I actually have about 3/4 quart of Red Line MT-90 left over from my Toyota MR2 transmission oil change. I got that from O'Reilly, which also sells MT-LV (ship to store or delivery). $24/quart.

A service writer at Hyundai said he's never heard of someone changing the GRU oil and doesn't think there is even a service code for it. But I'd probably go for a less expensive private garage anyway.

I like to think I drive pretty smoothly except for sudden stops to avoid unexpected moves by others. However I have been running at Eco and Regen 3 (with speed limits turned off). The car was over four years old with 40K miles when I bought it. The issue started around 41.5K, possibly after an emergency stop. Or maybe the previous owner always ran Regen 1 or 2 and my use of 3 brought the issue to the fore. Would 2 be less, um, abrasive?

 

[Kiwi]

No need to avoid using Level 3 after breaking-in the new GRU, just take it easy during the first 1,000 miles and use the other level settings if practical. It's my suggestion based on minimal but not zero evidence from the experiences of other owners.

Dealers globally seem to be unaware that Hyundai's Mobis division made a minor design mistake that (IMO) causes this problem. It's been widely reported that there is no dealer service code for this oil change and in many cases they use one for an automatic transmission change, over $400 in any currency. One had used a rear-axle differential oil change, US$140, in N. County as it happens. Had the GRU been correctly designed the oil would last the life of the car and the factory recommendation of an 'inspection' at 90,000 miles would have been adequate.

The gen-2 Kona (2024+) and Niro's (2023+) powertrain design was outsourced, based on media reports from several years ago and the resulting changes (3x more oil and a filter) essentially seems to have negated the issues caused by the still-present loose magnet.

The MT-90 (75W-90) you have is a GL4 and ok to use to top off any oil change up to about 100 ml. So, you can use that with the MT-LV.

 

[Richard&Cat]

Based on what I've heard from three other owners who have done this I'd leave it till 500 miles. Try to drive a bit more gently if possible which might avoid knocking off any large wear particles. Speed is not a big factor, just high acceleration and regen.

You'll want to carry out two oil changes. If you (or your mechanic) doesn't spill any you can get away with 1 qt each change. The added 0.1 litre can either be ignored or taken out of the old oil, or use any other gear oil. But if it's pumped in while the car is on a lift there will be some 'spillage' and that's why I've suggested buying 3 qts. At least it's less expensive in the US and off the shelf locally from a speed shop. I'd pay $60 each here and have to order it.

But, when I did a search for Redline it's not readily available in San Diego either so it might be easier to buy this Bel-ray oil which is highly reputable and shipped in litres. 75W will be fine, give them a call. It's dirt cheap as well.
View attachment 9776 View attachment 9777

Some is normal, most people just turn up the radio, I'm the only person I know who doesn't turn on thr radio at all, that's how I know some noise in regen mode is normal

 

[joeaverager]

Got it--you were allowing for two changes with 3 quarts. I actually have about 3/4 quart of Red Line MT-90 left over from my Toyota MR2 transmission oil change. I got that from O'Reilly, which also sells MT-LV (ship to store or delivery). $24/quart.

A service writer at Hyundai said he's never heard of someone changing the GRU oil and doesn't think there is even a service code for it. But I'd probably go for a less expensive private garage anyway.

I like to think I drive pretty smoothly except for sudden stops to avoid unexpected moves by others. However I have been running at Eco and Regen 3 (with speed limits turned off). The car was over four years old with 40K miles when I bought it. The issue started around 41.5K, possibly after an emergency stop. Or maybe the previous owner always ran Regen 1 or 2 and my use of 3 brought the issue to the fore. Would 2 be less, um, abrasive?

It looks like Redline MT-LV was scarce everywhere a few months ago but easier to source now. Back then our local O'Reilly couldn't get it though it was in their catalog. Back then I ordered it from Summit Racing. Today I ordered two more quarts for another change (flush) soon from Bimmerworld with free shipping. The price seems to be $23.10 everywhere.
I checked prices at https://www.froogle.com which is a website operated by Google.

Our Kona has 39K miles. I'm not sure the GRU had ever been serviced before I did it last weekend. The drain/fill plugs were pristine (outside, no tool marks). Just the slightest bit of metalllic sheen in the oil pan afterwards. My gearbox is quiet except under hard regen. It sounds exaclty like OP's new GRU.

I was defaulting to Level 2 regen but last weekend changed that to Level 1 as the default. Of course whatever the auto regen doesn't get done I'll supplement with the brakes and that will be blended friction brakes and more regen so I'm not sure changing down to Level 1 really makes that much difference.

My main motivation was to be smoother. When In Reg 2 - there can be a a lurch when I let off the gas quickly and my engineer brain wonders if I'm momentarily binding the gears in such a way I'll damage them in the long run. Short of like a rough shift in a manual transmission car. Not a problem in the short term but in the long term, the transmission might be noisier for it. Since I plan to keep this car for the long term, I worry about stuff like that.

If I'm coasting down the mtn roads around here I'll bump the reg up to L2 or L3 with the paddles. My daily driving though is on rolling hills, not steep mtn roads.

Really enjoying this little car.

 

[Kiwi]

... The drain/fill plugs were pristine. Just the slightest bit of metallic sheen in the oil pan afterwards. My gearbox is quiet except under hard regen. It sounds exactly like OP's new GRU.

The stock plugs are non-magnetic so they will always be clean. By 39k miles all but the most recent wear particles will be completely reduced to an invisible size. In most cases the oil is black (IMO, due to aluminium) but there have been one or two examples out of perhaps 100 where it was relatively clean. But ongoing changes at some convenient interval can only help, as would adding a magnetic plug or two.

Between about 1,000 to 3,000 miles is where particles are still large enough to be visible according the many photos and videos posted over the years.

Even though the braking system is generically described as 'blended' I believe it uses 100% regen unless it can't. There's no reason or evidence that it would need to apply any friction braking while slowing at a comfortable rate above a walking speed. The fixed regen 'levels' would be intended for exactly the situation you describe - driving convenience on hilly or city driving and there's no need to avoid Level 3 if that's what you want to use.

Even though there's been some speculation that using high regen could invite future GRU noises I'm doubting that's a factor. There's been one case reported of an owner on their third GRU that they believe was needed due to their self-confessed 'hard' driving. Designing a gearbox for an assessed load is basic engineering and I believe it's very likely to be correct for the Kona. There has been one case of a broken diff carrier due to wheel spin on ice suddenly finding traction and one or two reports of catastrophic GRU housing failures from unknown causes. The vast majority of failures are due simply to excessive bearing noise, the 'wheel of fortune' sound.

My own GRU is still quiet at 30,000 km (18k miles) and with annual oil changes I'm optimistic that it will survive the life of the car despite that my first change was far too late at 19,000 km (12,000 miles) to prevent some some bearing damage. It does whine under high loads but that's from gear meshing and somewhat expected for a 2-stage reducer. Worn bearings 'rumble' and I'm not hearing that. The 75W-80 grade I'm using this year is definitely quieter than the 70W-75 I was previously using, noting that I can justify this viscosity change because I don't need to drive over 100 km/h and my local climate doesn't drop below freezing.

 

[joeaverager]

The stock plugs are non-magnetic so they will always be clean. By 39k miles all but the most recent wear particles will be completely reduced to an invisible size. In most cases the oil is black (IMO, due to aluminium) but there have been one or two examples out of perhaps 100 where it was relatively clean. But ongoing changes at some convenient interval can only help, as would adding a magnetic plug or two.

Between about 1,000 to 3,000 miles is where particles are still large enough to be visible according the many photos and videos posted over the years.

Even though the braking system is generically described as 'blended' I believe it uses 100% regen unless it can't. There's no reason or evidence that it would need to apply any friction braking while slowing at a comfortable rate above a walking speed. The fixed regen 'levels' would be intended for exactly the situation you describe - driving convenience on hilly or city driving and there's no need to avoid Level 3 if that's what you want to use.

Even though there's been some speculation that using high regen could invite future GRU noises I'm doubting that's a factor. There's been one case reported of an owner on their third GRU that they believe was needed due to their self-confessed 'hard' driving. Designing a gearbox for an assessed load is basic engineering and I believe it's very likely to be correct for the Kona. There has been one case of a broken diff carrier due to wheel spin on ice suddenly finding traction and one or two reports of catastrophic GRU housing failures from unknown causes. The vast majority of failures are due simply to excessive bearing noise, the 'wheel of fortune' sound.

My own GRU is still quiet at 30,000 km (18k miles) and with annual oil changes I'm optimistic that it will survive the life of the car despite that my first change was far too late at 19,000 km (12,000 miles) to prevent some some bearing damage. It does whine under high loads but that's from gear meshing and somewhat expected for a 2-stage reducer. Worn bearings 'rumble' and I'm not hearing that. The 75W-80 grade I'm using this year is definitely quieter than the 70W-75 I was previously using, noting that I can justify this viscosity change because I don't need to drive over 100 km/h and my local climate doesn't drop below freezing.

I edited my post to reflect this but I meant the plugs had no tool marks on the outside so probably not serviced yet. I did install the Votex magnetic plug you referenced and recommended in another post.

After the oil change, the gearbox definitely whines a tiny bit more under load. I'm wondering if the OEM GRU oil included something that the Redline MT-LV oil did not. Moly? Pure speculation on my part. It is not obnoxious but I've spent a fair bit of time overthinking about the possible cause. We get four seasons of weather here but I've thought about using 75W-80 oil. Maybe next spring I'll test that. Our winters are generally 30F-45F but can dip to much lower temps occasionally. I don't want to damage the GRU.

Without an ICE engine bolted to the GRU, the GRU will never heat up much in the winter. The lower ambient temperatures of the season may be part of the cause for the GRU whine as much as anything else. I recently watched a winter test of a Chevy Bolt on YT. Their temps were ~38F and that gearbox also noticeably whined as they entered the interstate. The whine was gone later in the video after they were driving at ~70 mph even at slower speeds. VERY speculative evidence there.

 

[Kiwi]

Absolutely, audible gear whine is a characteristic of oil being too viscous and over time that could be damaging to gear teeth. It's difficult to select an optimum oil for a gearbox catering for the massive range of tooth-pitch speeds and ambient temperatures found in an EV gear reducer. I checked the OEM choice of 70W years ago and found that it is the correct viscosity for the top speed of the Kona.

The OEM oil color is described on the datasheet as "clear brown". I don't believe there is any chance that it has unusual additives, especially moly. Every other current EV (including the gen-2 model Kona) uses an ATF which has the same viscosity and EP rating as a 70W GL4 gear oil.

The mild conditions here in NZ allow me to stretch that to a thicker oil and I'm optimistic that it's working well. I need to cover more distance and check the condition, but that won't be until March 2025 at the earliest.

NR = not recommended simply because they are not described as a "full synthetic".

 

[sd_kona]

Be sure and change the oil to avoid a repeat performance. I'd do that by 500 miles and again at 1500. Theoretically any garage with a lift can do this easy task. You'll need 2-3 US qts Redline MT-LV. The required fill is 1.05 litre. Plugs torqued to 30 lb-ft, reuse the original gaskets.

I'm coming up on 500 miles and thinking of doing this oil change myself. Is there a master "how to" page or video on that, either here or on another forum? Scrolling through the 400-post megathread here, I see some advice like this. There's a Reddit thread that cites a YouTube video, though they don't mention the need to tilt the car up on the left to complete the fill. I see that torque recommendations have varied (or evolved), and that a new, magnetic plug may not be needed. My neighbor has a heavy-duty hydraulic jack that I could use but otherwise I'm starting from scratch buying ramps etc. Oh and it's a hilly neighborhood with a cramped one-car garage so getting it level will be a challenge...

 

[Kiwi]

The first procedure I wrote in that post you've linked hasn't changed, noting that I've only used the ramp method and rolling the car off momentarily while filling. The video from RTS uniquely placed the ramps in a depressed part of ground to keep the car level. It's not mentioned that this is an opportunity most of us won't have.

Note that the posts in that thread reflect owner's individual experiences and none of us are under any obligation to document the perfect universal procedure. Using a workshop is always the safer option for those who don't have the required tools and experience. I suspect even Pep Boys could do this given brief instructions and adequate oil supplied so they can pump it in from underneath. The shop time should be around 45 minutes.

If you're spritely and slim it could work with a single floor jack and safety stand but it won't be fun finding the right reach and angle to crack the plugs loose. Any process will be safer and go smoother if every step is conservatively planned and all tools required are on hand. Improvising on the fly is how people get injured and the Kona is a heavy car for the size.

The oil fill opening is located at the rear-left end (viewed from the driver's seat) of the GRU casing. If that corner is elevated a measured quantity can be used rather needing to fill until it spills while level. The filler plug can be re-installed finger-tight from above. Konas plugs have had needed two socket sizes over the years (24 then perhaps 23mm?) and that will need to be checked beforehand which can be done from above. The stock plugs and the Toyota variant can be torqued to 30-33 lbs-ft and the Votex to 22 because it has a narrower shoulder and is made of slippery stainless-steel. New washers are not normally required.

I've done the job six times now with ramps and am comfortable with the method I've described. I'm reluctant to take any shortcuts that could risk either safety or finding myself in a pickle that needs to be resolved under duress.

I had a quick search for ramps at O'Reilly but the choice looks dismal. Pep Boys don't even have an online catalog. Walmart is better but I can't see that buying suitable ramps is less costly than going to a local workshop.

If you purchase ramps be sure they can handle the approx 2000 lbs at the front axle and they have a means to stop them from skidding on a concrete surface when the car is driven up. A rubber footing at the low end is typically the solution for that. Another required feature is a means of minimising the risk of driving off the ends of the ramps. In any case you should use a large mirror positioned again the garage wall to view the driver's side ramp or better yet another human to help position the car correctly. One foot on each pedal is effective to move the car slowly and with sufficient precision. At the top apply enter Neutral, slowly release the foot brake to let the car settle into position, then apply the parking brake, then select Park in that order. That will minimise the chance of hearing a loud (but harmless) clunk when driving off the ramps.

 

[sd_kona]

Thanks @Kiwi for the detailed reply. Oddly my question (post #32 in this thread) seems to have disappeared. Did I break a forum rule by posting an outside link? I'll re-post the link to the other thread at least:

https://www.hyundaikonaforum.com/threads/reduction-gear-oil-change-seems-to-be-a-must-in-a-kona-ev.5198/?post_id=44518&nested_view=1&sortby=oldest#post-44518

My street is on a slope so I might be able to find an appropriate place to go up a ramp and get level. In fact we have 6" curbs so if only needed to raise one side, and if that's enough, I could just drive up a curb.

Maybe I'll call my private mechanic and ask if this is something they could handle.

 

[Kiwi]

It's visible to me but I simply failed to see it! You can see I responded on Reddit at the time and nothing has changed.

I'd forgotten about the ever-popular drive-up-on-the-curb technique, perhaps because it's not commonly seen here and our curbs are short. That could work very well.

I think you've got good ideas now and understand your options.

 

[sd_kona]

Ah okay, I found it. It was under the original post. I had to click "1 Reply" to see it (link). Then I went up in the URL and changed to nested_view=0 and everything showed up in the order posted. Phew!

 

[joeaverager]

I've had a Toyota MR2 Spyder for 23 years. I know when it is not happy just by listening to it. (That fluttering noise that turned out to be a failing transmission.)

I am still trying to figure out how this 2020 Kona EV is supposed to sound, what's normal and what's odd.

It seems to make a lot of noise during a regen. Specifically, if I'm on a smooth section of highway (limited road noise), going 65 mph, regen set to 3, and I take my foot off the accelerator, the car not only slows down pretty rapidly, it makes a "winding-down" noise that almost seems like it's getting louder. Both the braking and the noise are not unlike down-shifting to 3rd gear the the Toyota when you're going 65.

I tried to capture the regen noise in a YouTube short--don't know if it will come through. is this level of noise normal?

Oh and while I'm thinking of it, do the brake lights go on during regen?

Yes. I've spent a fair bit of time on dark mtn roads. When regen kicks in the brake lights come on and make it look like you are riding the brakes all the way down the mtn.

Your regen sounds like a lower tone than mine. I get a higher pitched motor whine. Worst case, your car will develop the "wheel of fortune" sound with time.

Be sure and ask your dealer about it i.e. register a complaint while the car is under warranty.

 

[sd_kona]

Yes. I've spent a fair bit of time on dark mtn roads. When regen kicks in the brake lights come on and make it look like you are riding the brakes all the way down the mtn.

Your regen sounds like a lower tone than mine. I get a higher pitched motor whine. Worst case, your car will develop the "wheel of fortune" sound with time.

Be sure and ask your dealer about it i.e. register a complaint while the car is under warranty.

Thanks Joe. That's good info on the "brake" effect.

I did in fact get the GRU replaced under warranty, barely (2nd owner - 5 years). Now preparing to change the oil in the new GRU.

 

[joeaverager]

Thanks Joe. That's good info on the "brake" effect.

I did in fact get the GRU replaced under warranty, barely (2nd owner - 5 years). Now preparing to change the oil in the new GRU.

I just did my oil change a moth or so ago. Bought a second bottle so I can do it again sooner than necessary to wash out whatever is left over. Then I ought to be good for a long time.

 

[sd_kona]

My local shop would do this for $85 labor, very reasonable, but requires me to leave the car all day, which adds two $15 Uber rides and extra time.

Meanwhile I stopped by Walmart yesterday evening and purchased a pair of 6000-lb RhinoRamps for $51 plus a set of large 1/2" drive metric sockets for $16. AutoZone will loan a 1/2" torque wrench for a $100 deposit. I think that just leaves a trim puller and the liquid management (tubing/funnel/measuring/disposal). And probably I should have bought the wheel chocks as an extra safety thing.

Anyway, as I try to picture doing this, I'm going through the procedure from the other thread and wanted to clarify a couple things:

Car on ramps, remove front splash cover, remove both plugs, drain oil, clean and replace drain plug, torque to 33 ft-lbs. A new 18mm ID aluminum washer is optional.

Check.

Run a 0.5m length of 15mm OD (or smaller) PVC tube from near the 12V battery to inside the filler opening.

Check.

Drive car off ramps. Lift the left-front slightly at the factory jacking point, enough so you can reach under and replace the fill plug after filling.

So drive a few feet with no oil? Is it important to lift it? I think I can touch the filler plug from above, though I can't see it (see photo below). It seems this Kona did not come with a jack (or spare tire) so either I'd use the little jack from my Toyota MR2 or I'd have to buy/borrow one.

Add a carefully-measured 1.05 L using a thin neck funnel pushed into the tubing from above. Reach under, remove tubing and hand-tighten the filler plug.

Or maybe from above? Need to find a 1-liter bottle around here...

Lower the car, drive onto ramps again, tighten filler plug, reassemble.

Check.