Say Goodbye to the Flat Spotted Tires / Shuttering Theory

[Risktk1r]

This makes sense and its similar to an issue I had with a 2001 BMW 740i sport. But with 142k miles. The center driveshaft support , also rubber had worn out. However, I have a 2020 G80 3.3 sport AWD. 3300 miles. At exactly 30 mph the car shakes, clearly coming from the rear. Took it to the dealer. Was told the cannot replicate the issue. So I took it back and told them it vibrates at 30 mph. To replicate this, I suggested driving the car to 30 mph and engage the cruise control. This way you can't miss. I also handed them a copy of a Service bulletin describing how to repair this very issue. They kept the car, and said they will do the TSB ( two washers under the center drive shaft support, have to order parts? ) . But on the repair order they wrote that I am having this problem because I am engaging the cruise control at too low a speed and straining the transmission. Went so far as to say it was designed into the car. ( see attached. ) So I got in the car, when up a hill in their parking lot, started down the hill, put the car in neutral, and at 30 mph vibration is back. No "strain " on anything. I went back inside and ask the service advisor to take a ride with me. He refused, saying he cannot leave his desk, he has customers coming in. ( I though I also was a customer) So I am going back yet again, to debunk this ridiculous diagnosis. I worked for Porsche and BMW when I was young. The car needs either a new drive shaft, or to have the shaft balanced. Several people have mention it is worse when cold, and that is true of my car. 37 degrees here this am, and it was shake rattle and roll. Genesis knows about this and I intend to keep after them until they fix it. I am attaching the TSB also. Hope this helps.

 

[princelybug]

So sorry to hear. It’s ridiculous how some dealers treat customers. The service manager may need to be spoken to. How can they refuse service even with an existing TSB?!

 

[Risktk1r]

My assumption is they think we are all morons and this is the first car we have owned.

 

[EdP]

My assumption is they think we are all morons and this is the first car we have owned.

Seems like that is the industry standard since the auto dealer was invented. Every brand has some. Fortunately, there are a few exceptions.

 

[glennk]

The dealer makes FAR MORE off non-warranty repairs. So, they shirk their responsibility for anything else. You may have to find another dealer.

 

[todonnell]

Finally got around to getting the car up in the air to do some investigating. With three items on the list, this turned into a two-dayer. Rotate tires, craft a drain line so I don't have to lift the car to change oil (yeah, I did just buy a vacuum pump but it will be quicker this way). The third was the driveline shutter/noise.

I actually got quite elaborate/anal on this (I tend to do this on a lot of things). I set up three lav mics and laptops running Audicity to record where the noise was coming from. One mic on the rear u-joint on the front prop shaft, one on the rubber coupler and one on the mid bearing/U-joint.

View attachment 29513
With the car up on stands under the suspension so the axles weren't in droop, I ran the car up to 30mph. Expecting to hear the usual clicking, it didn't happen. But... it had a nasty vibration like I've never felt before. My car just emits a few minutes of clicking from under the console and then it goes away. One key thing with this test is the wheels were off. So that ruled them out.

Since the clicking I expected didn't happen, the mics didn't help much. Big waste of time in setting all that crap up.

Here's the reason you can kiss off the tire theory... I disconnected the rear driveshaft rubber coupler from the trans, ran it up again to 30mph and the vibration is GONE. (I assume the clicking also) Too bad you can't road test it this way without completely removing the rear driveshaft.

View attachment 29514

Before I bolt it all back up, I wanted to check with others here who have the vibration. I've never really noticed the vibration, maybe because the 30mph portion of roads from my house to town or to the interstate are so rough, I never feel it. After five miles there's no clicking. This only happens on the initial drive of the day.

Does your vibration lessen after a few miles? If that is the case, I'm leaning again to the rubber coupler. If it were a rear driveshaft balance issue, it would be there every time the car was at 30mph.


Here's a couple pics of the drain hose. I found a 14mm x 1.5 to AN6 adapter for the pan. A hose which leads to the outside of the car behind the front left fender well liner. I put an old ratty piece of firesleeve over the hose where it is near the exhaust to protect it from heat. I ty-rapped it near the outer edge of the undertray panel and when it comes time to drain the oil, I'll just snip the ty-rap and let it hang out over a pan.

View attachment 29518

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View attachment 29517

This is great bit of research. I have a 2015 Ultimate and I have the noise and vibration at the 29 to 35mph range. I have a ticking noise as well but I feel like it is more the car vibrating wires in support column behind my head or wire around the glove box. I can’t narrow it down but it’s pretty frustrating.

Also, I thought the sound disappeared at higher speeds until my last trip to my company HQ 67 miles away in Georgia. I grabbed a glass of water with no lid and you can monitor the vibration. The water literally rumbles out of the cup at low speeds but then smoothes out at high speeds but still the water cup has a ver steady dose of vibration.

My engine has an unusual vibration at idle as well. I believe it is as stated above, a rubber coupler, or drive shaft that is not balanced or the motor mounts.

I have gone through the Michelin MXM3, BF Goodrich, and now I have Toyo tires. I want to put new rims on just to rule them out but instead will put the car on clocks and test for vibration due to the tests above.

This is my second Genesis and we also have a Kona so I’m taken aback by the lack of ownership with Hyundai on this give all of the threads here having the exact same problem.

 

[todonnell]

This is great bit of research. I have a 2015 Ultimate and I have the noise and vibration at the 29 to 35mph range. I have a ticking noise as well but I feel like it is more the car vibrating wires in support column behind my head or wire around the glove box. I can’t narrow it down but it’s pretty frustrating.

Also, I thought the sound disappeared at higher speeds until my last trip to my company HQ 67 miles away in Georgia. I grabbed a glass of water with no lid and you can monitor the vibration. The water literally rumbles out of the cup at low speeds but then smoothes out at high speeds but still the water cup has a ver steady dose of vibration.

My engine has an unusual vibration at idle as well. I believe it is as stated above, a rubber coupler, or drive shaft that is not balanced or the motor mounts.

I have gone through the Michelin MXM3, BF Goodrich, and now I have Toyo tires. I want to put new rims on just to rule them out but instead will put the car on clocks and test for vibration due to the tests above.

This is my second Genesis and we also have a Kona so I’m taken aback by the lack of ownership with Hyundai on this give all of the threads here having the exact same problem.

Just to add the last time I was in Rick Case they gave me two sheets of paper telling me to buy Michelin or Continental tires. Total BS!!

 

[doucmehu]

2015 (V8) with fluttering @ 28-35mph, some vibration... Funny, even before finding this thread I wondered if it was the driveshaft guibo / flex disc, and it appears very likely. EXACT same symptoms as my Touareg. I was able to fix this for under $10 and about 2 hours following this guide. It looks wonky as heck, but there are 100's of Touareg / Cayennes out there with this quick fix in place, for many miles / years. Mine has been like new since, and no degradation of the repair.

Haven't ventured under the Genesis yet to see how viable this might be, but curious if anyone else had thoughts on this as a potential flutter / vibration fix for our sedans?