As the new batteries roll out I think our attention will start to lean towards the 'issues' reported about motors and gearboxes failing. I know of one just around the corner from my house, so I know its very real. I often hear odd whining/moaning noises that dont sound like they belong but I know the dealership would simply wave away until much worse. Has there been any real pattern to the ones that fail? How many kms go by before we start seeing these issues? Is there any preventative action we can take? Does the gear oil show a potential issue that warrants action? EG would filthy oil show bearing failure and thus prompt Hyundai to start replacing worn parts? Can we modify our motor/gearbox junction using the new longer bolts etc or do you need the new motors to do that? Thats enough questions. If anyone has thoughts or actual answers, please educate me.
There's an older thread here that might interest you. Therein are more links to even older threads about strange noises. It seems like the problems start to manifest pretty early, within a few thousand km/mi or so. Sampling and testing the oil in the gearbox should reveal any metal content which is an indication that something is amiss if there's a problem in the gearbox. If the problem is with the motor spline, I wouldn't think that the gearbox oil would be affected since it doesn't circulate through there.
There's one thing you can do right now that will give your gearbox the best chance to stay healthy and that is change the oil if you've reached (an estimate on my part) perhaps 20,000 km. It's an easy DIY if you're so inclined and have the tools but also easy for any shop to do who has a lift. You can use Redline MT-LV or Hyundai dealers I expect would use their own branded DCT transmission oil. In my opinion it's well worth the $150 that they might charge. Whether it will help avoid the knocking problem is conjecture at this point because we don't have any evidence as to what's causing it and why the motor is often involved. I'm going to say "no" to all those questions because despite all the motor and gearbox replacements we're not seeing a relevant TSB. Meanwhile the Kona EV is selling second only to the Model 3 here last month.
