Vibration on deceleration

Got another problem. I've been noticing lately, that when I decelerate I get a vibration/rumbling in the foot pedals and steering wheel. If I touch the rear view mirror I can also feel it. If I accelerate it goes away until I decelerate again. But it's very light and I'm sure if someone was riding in the car they would think I was nuts.

In the mornings the tires feel like they have flat spotted because the wheel does shake just a bit. But after about 10 miles on the highway the shaking goes away and it smooths out. However, once I decelerate (no matter how lightly or how hard) I get that rumbling/vibration. I have a little less than 8000 miles on the car and I just can't believe it could be the tires. I've owned a lot of cars and never had one where the tires caused a deceleration rumble. I've had u-joints cause that, but never tires.

Anyone ever have a similar issue?

I have experienced the exact same thing the past 2 mornings...almost like a tire flat and just on deceleration...only 350 miles on mine. I'm interested in finding out more about this issue?

At which speeds do you guys feel this vibration?
I noticed the same thing with mine when slowing down in the 20-40 mph range.
Long story short: drive train is out of balance.
the dealer went through great time and pain to eliminate my rattle. They ended up swapping out all four wheels and tires (not necessary), and both propeller shafts with the support bearing - the whole nine yards.
They initially swapped out the tires thinking that my 2009 hat some flattened spots from sitting.
Then they swapped out the front propeller shaft, but that wasn't enough. I'm sure Hyundai corporate has caught drift of this, and mention of this to your service guy at the dealership should help expedite.
N.B. propeller shaft is a fancy word for drive shaft. It is actually in two pieces, held together in the middle by a support bearing. All this needs to be WELL BALANCED and put together properly.

I no longer feel those vibrations in my car

2009 Genesis 4.6

My 4.6 sedan does this too but only on deceleration between 42KM/H and 40KM/H and only for the first few minutes on cold start.
I brought my car in to the dealer today and they will see tomorrow morning.
I'll keep you posted on the outcome.

yuhaze,
I have printed what you wrote and gave it to the mechanic...we'll see what they can do with that info.
Thanks

If you are feeling this while applying the brakes, it is probably some warpage in the rotors. If it goes away once the brakes have warmed up, it could be some glazing that wears off. The dealer should be able to turn that out.

Well, late last night on the highway I noticed that it's now doing it while driving normally (acceleration, deceleration or just cruising). And the vibration is a very high RPM vibration as opposed to a tire that is out of balance. I know of one other person that had this problem and it was their tires. I'm hoping that's all it is. Looks like I'll be making a call to the dealer today to see if they can get me in on Saturday.

jrgheri: That is exactly how mine started out. It felt like a tire or tires was flat spotting. I've have had a lot of cars over my life time and a lot of tires. And occasionally you do get tires that flat spot. But, after about 5-10 miles of driving in the morning that goes away and they are as smooth as ever. In this case though, it never seemed to "quite" go away. There was always an underlying soft rumble of a sort that wasn't shaking the wheel like an out of balance tire would.

ImInPa: I definitely wish it were the brakes because I'd have concrete proof of the vibration. But in this case the dealer is going to think I'm crazy.

Thanks yhaze and QCTLG. Please let us know what they say QCTLG.

I just got a call from the dealership...
They have sent my work-order to the Hyundai Head office (Toronto) and is waiting for a response from them.

I am going to pick-up my car now while they wait for further instructions.

Will keep you posted...

BTW, spoke with the head mechanic and he said he heard the sound when he tested it this am.

Hyundai called me to bring my car in today to do the repair.
The SM told me they got a TSB from the USA and will take approx an hour to do.

I'm picking it up at the end of the day.
Tomorrow...I will try the car to see if it does the noise again.

Will keep you posted.

I feel lucky that I know what USA stands for,
does SM stand for service manager?
What does TSB mean?

yuhaze said:

I feel lucky that I know what USA stands for,
does SM stand for service manager?

Click to expand...

Yes

What does TSB mean?

Click to expand...

Technical Service Bulletin

I just picked up my car...Here's what the SM said in a nutshell:
All he had to do was add another washer (on the nut and bolt) where to 2 drive shaft attach to make the 2 drive shaft pieces more horizontal. Hope this makes sense.
He said he had to add a 4.5mm washer.

Now I need to get back to him after I try it tomorrow morning.

will keep you posted.

yuhaze,
Many thanks for what you wrote down. I printed it, gave it to the SM and it helped alot.
Merci

je t'en pris

Thanks for the update. Definitely appreciated.

Ok,

Today, this morning, started the car....hit the road...and NO NOISE whatsoever...I can't believe a .5 cent part (Washer) cleared up the problem.

Major thanks goes out to yuhaze for his suggestion.

Sincerest regards,

Driveshafts use "U-joints" (Universal Joints) to allow the driveshaft to flex a bit. On pickup trucks and big moving van type of trucks, you can see the driveshafts and u-joints when you are along side those vehicles. Since the driveshaft has to go up-n-down when the rear suspension moves (on those vehicles) the driveshaft must have some "pivot" or "flex" capability - that's the job of the u-joints. Basically a u-joint is a "+" center piece. The "input" end of the u-joint has a "C" shaped end that grabs two ends of that plus shape (and pivots on those two ends) and the output end uses another "C" shape to grab the other two "+" ends. Imagine the input and output shafts lined up, perfectly horizontal. Turn one, it turns the "+" (the "spider" of the u-joint), and that turns the other "C" shaped "yoke" piece on the output driveshaft. Simple, easy to imagine. Now bend/flex the driveshaft about 10 degrees. You can see how the "+" allows it to bend - even if the "+" isn't lined up with the direction of the bend... both "C" shaped yokes will twist on the "+" a little bit. What's NOT intuitive/obvious though is either the input or the output shaft will have to turn/rotate a little bit. Imagine the "+" is turned a bit relative to the "bend" we're putting into the driveshaft - so it's more like an "X" now. As the driveshafts go from horizontal to bent, one of them is going to turn (forwards or backwards, depending on the angle of the "+" or "X" spider) a little bit. Now if the engine is turning the input driveshaft at a constant RPM, the output driveshaft will still turn at the same RPM... but it WON'T be turning at steady rate: at some point in the 360 rotation cycle it'll speed up, at other points it'll slow down. The AVERAGE RPM will match the input shaft RPM though.

When u-joints are used on a driveshaft, there should be at least 2. Ideally whatever angle the first one is "bent" through, the second one will be bent through "minus" that angle. Then the speed-up/slow-down from the first u-joint will be canceled out by the second u-joint's output shaft. If the two u-joint angles aren't equal-but-opposite-sign to each other, some of this speed-up/slow-down will remain at the end of the driveshaft... putting a herky-jerky rotation motion into the differential and thus the rear wheels. You'll feel that vibration. On cars with 3 u-joints, one of the driveshafts is supposed to be oriented so that one u-joint NEVER has any angle to it - the input and output shafts are always "flat" or "parallel" to each other. This is probably what was screwed up on a couple Genesis cars... a washer/shim moves either the end of the transmission up/down or more likely the support bracket for a "center u-joint" to make it line up perfectly with the transmission.

mike c.

p.s. Look at some of those truck drive shafts again... ideally the "bend" angle across any u-joint is less than 4 degrees. Any more than that really stresses the u-joint. Jacked-up pickups often violate this guideline and need beefy u-joints as a result.

My 2009 vibrates at about 26 mph. Bought it Jan. this year. Then clunks and jerks when decelerating. The dealer replaced the drive shaft. Still did it. I was told today 6/21/10 that a part to fix is being released and it will be 10 days before it gets here. I see where a washer fixed the probem in others, any one heard about a bolt that has to meet some sort of torque specs before they could fix the shaking?

I have exactly the same problem as you guys described. Picked up the car at
end of April and have the problem ever since. The local Toronto dealer changed
all 4 tires and the problem is still there. I mentioned this forum thread to the
dealer and they said they cannot find the TSB in their Canadian database.

QCTLG, can you tell me which dealer did you go to so that I can ask the service
guy to contact them and find more information about the TSB? Thanks a
million for your help. It is a pain in driving the car fearing the vibration pops
up.

For me it was an out of balance propeller shaft, carrier bearing combination.
I have also heard from another forum member (probably related to bulletin) that a simple washer placed inline eliminates a small dimensional discrepancy that causes the vibration.

My 2014 3.8 has the same issue. Mine happens when I am at 60-70 mph. It sounds like the tires but it's not. They added this washer from the TSB and it's still happening. They are getting back to me. I have no idea if this is a serious problem and would fall in line with the leMon law if they Cannot fix

i appologize, this should be moved to the sedan section, my fault.