Vibration when coasting/deceleration only

[repairman54]

There is even a door sticker that says to add 3 psi to the tires if you intend to drive over 100 mph. The only Ford I have seen this sticker on is the Ford GT. Not even my Mustang had this sticker.

My '17 Continental had the add 3 psi. sticker. 2.7 twin turbo .

 

[metroplex]

My '17 Continental had the add 3 psi. sticker. 2.7 twin turbo .

Same car as the Fusion/MKZ so that makes sense. Probably has 14mm lug studs as well with 150 ft-lb lugnut torque. I bet the MKZ 3.0 has that sticker as well, but it is such a low quantity vehicle I think I might have only seen 1 in the wild.

 

[Genesis Guy]

Same car as the Fusion/MKZ so that makes sense. Probably has 14mm lug studs as well with 150 ft-lb lugnut torque. I bet the MKZ 3.0 has that sticker as well, but it is such a low quantity vehicle I think I might have only seen 1 in the wild.

Hi. I have a 2016 Genesis G80 and I'm facing the same problem during deceleration around 40-50mph. When I accelerate pass this range it does not vibrate, so I basically ruled out tyre damage or wheel balancing. When I'm decelerating at other speeds, above this range and below this range, it does not vibrate, so I ruled out other things. At first I thought it might be because it was decelerating at a specific gear, but then I experimented with that by leaving it in a higher gear throughout the range and then a lower gear throughout the range, the vibration was still there. ITS STARTING TO DRIVE ME NUTS. The dealership told me to change the engine and transmission mounts, but they can't guarantee anything, but I feel they also wanna do trial and error, but at the end I'm gonna have to pay for that, so I didn't get that done, and besides the mounts do look good and even if it was the mounts, the vibration should just get worse as the speed increases.

If anyone has any thoughts or ideas I could try, please let me know.

Also metroplex, if you do solve your problem, let me know.

 

[metroplex]

Yes will do! I'm still trying to see what a few other Fusion Sport owners find out.

 

[DallasCMT]

Hi. I have a 2016 Genesis G80 and I'm facing the same problem during deceleration around 40-50mph. When I accelerate pass this range it does not vibrate, so I basically ruled out tyre damage or wheel balancing.

Lots of good info on the Genesisowners forum. Also the Hyundai Genesis became the Genesis G80 in 2017, not 2016.

Thread 'Resolution to flutter at 25-30 mph' https://genesisowners.com/genesis-forum/threads/resolution-to-flutter-at-25-30-mph.28698/

 

[PandaBear]

I still have the same vibrations. Doing searches on CV Joints doesn't show any correlation with deceleration... Only acceleration. But this is the only forum that I've seen others mention CV joints could cause the vibes during decel. I don't hear any clicking while turning.

150 ft-lb IS the correct torque spec. Even dealerships get confused. These are 14mm studs, not your average 12mm or 1/2" studs. 110% confirmed they are 150 ft-lb. The lug wrench size is 21mm as well if that gives you an idea of how big the lug nuts are. There is even a door sticker that says to add 3 psi to the tires if you intend to drive over 100 mph. The only Ford I have seen this sticker on is the Ford GT. Not even my Mustang had this sticker.

Interesting, how do you change a flat with the tire iron being 1 ft long and a dude being less than 150lb? That seems to be dangerous.

 

[metroplex]

Interesting, how do you change a flat with the tire iron being 1 ft long and a dude being less than 150lb? That seems to be dangerous.

Same way I torque the lugnuts to 150 ft-lb using a torque wrench...

 

[PandaBear]

Same way I torque the lugnuts to 150 ft-lb using a torque wrench...

Do you have a torque wrench in your trunk always?

 

[metroplex]

Do you have a torque wrench in your trunk always?

No, but it has about the same mechanical leverage as the lug wrench in the Fusion Sport.... It's not that hard for a 150 lb guy to break loose 150 ft-lb lugnuts with the spare tire lug wrench, or to torque it back to 150 ft-lb or more.

 

[PandaBear]

No, but it has about the same mechanical leverage as the lug wrench in the Fusion Sport.... It's not that hard for a 150 lb guy to break loose 150 ft-lb lugnuts with the spare tire lug wrench, or to torque it back to 150 ft-lb or more.

I guess you can always jump on it to amplify the torque.

 

[metroplex]

I guess you can always jump on it to amplify the torque.

Nah I just use my pinky.

 

[alcyon]

When I had bad U-joints with a RWD, it would always vibe badly under acceleration. I don't recall it doing it under neutral throttle/coasting deceleration.

I don't hear any clicking or thumping while turning, or getting on the gas while turning. Every video I've watched and article I've written said the CV joints would go bad when it would vibrate under acceleration/power or make the clicking noises. I only hear the thumping on deceleration at certain speeds (40-60 mph or so). It's smooth at 70+ mph.

For RWD dont forget the center bearing if it has one.

 

[Schandyman]

Yes, I actually just rotated the tires about a week ago (the vibration has started about a year ago, so my tires are now rotated to back where they were a year ago) and torqued the lugnuts to OE spec (150 ft-lb).

Wow 150 ft-lbs

 

[metroplex]

Wow 150 ft-lbs

Yes that's in the owner's manual. These are 14mm lug studs. Not your regular 1/2" which is normally 90-100 ft-lb. Again, 150 ft-lb is the OE spec.