kn7671

My 2014 5.0 6AT has about 1800 miles on it, and I'm starting to notice a driveline vibration while on the highway between 65-85 mph.

I've ruled out a tire balance issue, as the issue goes away between the on-off-on throttle when maintaining traffic speeds. What the car has is a very light vrrrrb sounding vibration during light throttle or deceleration when a load is present on the driveline, which is nearly constant during my 35-mile commute.

Anyone else have this?

kcoTiger

sounds like the drive shaft is resonating. I'd take it to the dealership, drive it with the tech/service manager in the car, then drive one of their new ones on the lot to point out the difference.

If they don't want to play nice, sic Deysha on them.

Horspla

I'm working through the same issue you have. I can start to hear a very low harmonic at 45 mph and a very faint vibration in the butt and steering wheel. As the speed continues to climb, so does the frequency and amplitude. Seems like around 80mph it reaches peak. Last week I did a speed run (In a relatively safe place to do so) and from 80 on up to 140 it decreased to the point where it was negligible. It’s definitely at driveshaft frequency. I can also hear what I believe might be excessive clearance in the input yoke bearings lash or ring and pinion. It’s been to the dealer once and they could not find the issue. If it ever stops snowing here in MN I plan to take the tech out for a drive so he knows exactly what I’m describing.
John

kcoTiger

It's an expensive fix, but one option to consider is going to a one-piece driveshaft. If you track your car at all, it will provide some benefit over the two-piece, and of course it will take out some of the looseness during daily driving. It will also remove any resonance provided it's installed properly. If I had a 5.0, it's the first thing I'd change.

TheReaper

Put some more miles on the car and it will go away. Your tires are more likely to make noise than the drive train.

JPMotorSport

If you really think it is 'worse' than your previous examples you can take it in but I wouldn't be surprised if it's a bit tough to get help.

That's a hard thing to troubleshoot and frankly the 'acceptable' range with these vehicles is so wide I really think any noise is expected in some examples unfortunately... GL

kn7671

Maybe it will diminish a little over time, but I was hoping someone else would have had the issue and could tell me exactly what the fix was.

If it stays the same, I will probably change the driveshaft out to an aluminum one, but only after if visits the Ford Service Center once to get documented and looked at. If Ford finds something, unlikely, I will post an update to the cause.

mikeyt03

I had a vibration caused by the rotor retainer clips. It was making my rim not sit flush with the hub. I took the clips off and vibration was gone. If you have stock rims this shouldn't be an issue though.

08GOGTCS

I just bought a 2014 GTCS with the 3.73s. I have the SAME issue! It is not the tires. It is definitely coming from the drivetrain. The worst part of the vibration is when you let off the gas and it coasts down between 80 to 60, it really makes a vibration! I am dealing with the dealership right now, but I have a feeling I am going to be told it is within tolerance. Drives me BatChit at 75 MPH! Which is how fast you must drive on the Washington Beltway without getting run over!!!

Missouri Hoss

In my opinion, there isn't a noticeable vibration tolerance. My '14 GT TP doesn't vibrate at any speed and your new car shouldn't either. Make them fix it.

08GOGTCS

Good to hear, Bill. Thanks. The service department will get sick of me before this is over, if it does not get fixed.

FordService

Hi guys,

Has this concern been resolved for you?

Hi 08GOGTCS,

Please have your vehicle checked out at your Ford Dealer and PM me with your VIN, dealer, mileage, full name, and best daytime number so I can escalate this to the customer service manager for your area.

Deysha

Horspla

Deysha,

Not for me and I agree, it is annoying. I waited to see if on the outside chance different wheels and tires would make a difference and as predicted, they didn't. This is definitely driveshaft frequency. I've also noticed a lot of clunking in the driveline like ring/pinion play, U-joint/CV joint play or slip joint play and my guess is the problem is with one or more of them. Earlier, when I brought the car into the dealer for the issue, they said everything was normal. I respectfully disagree with them. The driveline in my old '86 F-150 with 168k miles on the clock runs smoother and quieter. Now that I have $3000 worth of wheels and tires on the car I'm terrified to have a Ford tech even touch the car.

John

kn7671

Nope. I have 7,200 vibration fulfilled miles so far over 3-months, still the same.

FordService

You might have to put your stock ones back on, Horspla. Then, both of you make an appointment and PM me with your VIN, dealers, full names, mileage, and best daytime numbers so I can escalate this for you as well.

Deysha

Lime GT

Hopefully the dealers are checking the driveshaft run-out's to spec.

Max driveshaft runout: 0.035" --- Max pinion flange runout; 0.009" ---

Max trans flange runout; 0.008".

I had a driveshaft that had the trans flange runout to spec but the mating flange welded to the driveshaft was off.

5_Ohhh

I have the same issue but nowhere near as bad as you guys.. 2014 Track Pack, 2500 miles. At 80 mph, the rear view mirror goes fuzzy from vibration, then disappears at 90.. has to be the driveshaft.. it's much higher frequency than a wheel balance or wobble issue. The 3.73 gears contribute to this issue.

Horspla

Lime GT...Thanks for the spec.'s, it give me something to work with. I know for a fact the dealer mechanic didn't take anything apart and measure. Quote from the service advisor when I picked the car up, "The mechanic looked at everything in the driveline and didn't see anything wrong." Well for me that was an underwhelming no $hit moment. I could have told them that much since I had already been under the car and looked at it too. I even put opposing torque through each joint with hand pressure to see if there was any play in them. They were convinced it was a tire balance issue in spite of the detailed information I gave them. All they did was a pressure balance and chastise me for tire pressure lower than the door tag says to run them. Whatever...I can do without "help" like that.

Deysha, thanks for the advice (I'm Serious) but I'm not going to swap out my new wheels and tires with the old ones just because a mechanic may not treat the expensive ones with the respect due them and his customer. I've proven, at least to myself, that the wheels/tires are not the problem simply by swapping one set for another and having the issue persist. Having raced for 20 plus years, I know the difference between driveshaft frequency and wheel frequency. My problem is how to get the dealer mechanic to tune into what I'm saying. If I didn't feel it was a warrantable situation, I would work it to resolution in my own garage.
Thanks,
John

Marcin K.

I think I know what you're talking about. Wheel frequency is lower, but the amplitude of vibrations is higher. In other words for out of balance wheel the vibration is ~ 2-3 times per second, but the magnitude of vibration is worse. While for a drive shaft vibration the magnitude is smaller but the frequency is higher, say 10 times per second or more (assuming 65mph for both cases). Would you agree?

Marcin

AlsCobra

Not many dealers are checking runout on driveshafts. You almost have to talk to the technician and ask them to do it. There are vibration tools to help diagnose driveline vibrations but they are nearly impossible to use. Lots of calculations to pinpoint exact causes. I've taken a couple classes on it. I've fixed a couple issues like this by simply unbolting the driveshaft from the rear end and rotating it 180. Bolt it back up. There's variations in the pinion hub and driveshaft. Sometimes the position they are in amplifies this. 180 position may help the variations cancel out. Just a quick test to try. Sometimes it works, sometimes it doesn't.