Vibration between 50 & 70 mph

[HoosierDaddy]

After much arguing they tell me they spoke to their regional ford engineer and determined this 35-42hz vibration is considered normal of convertibles and told me they will not investigate further unless I fix my tires.

Let me get this straight. They are saying there is nothing wrong now but will dig deeper after you change wheels/tires?

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[Cobra Jet]

So today has been fun. I went to pick it up from the ford of Murfreesboro dealer and as expected they wanted me to go for a short little test drive and while the car felt smoother the vibration was still there just not as pronounced as it originally was. So they take it back and put it back on the NVH analyzer after telling me I don't know what I am feeling and that it is normal blah blah blah. Then there with the new tires the NVH analyzer identifies a first order vibration between 35hz at ~30mph and 42 hz around 50-60mph that the scanner identified as 'wheel' and told me this was normal. Knowing this wasn't 'normal' at this point I realize they have no idea how to interpret the results of this machine, so being an engineer I dig into the elementary math of how frequencies and RPM work but this just goes way over their heads they instantly jump on the defensive by yelling at me about how I must be wanting a new drive shaft. I respond to this comment by stating I simply want my car to stop vibrating like my gf's vibrator at road trip worthy speeds. After much arguing they tell me they spoke to their regional ford engineer and determined this 35-42hz vibration is considered normal of convertibles and told me they will not investigate further unless I fix my tires. I know this doesn't make any sense but I have wasted so much of my day and so much times arguing with these idiots I reluctantly take my vibrating car back to discount tire where they road force balance them again and where they found high road force values they were half the values of what ford claimed them to be (using the exact same hunter force machines) and reluctantly agreed to replacing 3 of the four tires under warranty. The tires are on order and I will know Friday if this solves my problems but I highly doubt it. Btw at this point we have swapped out the wheels so many times Ford told me I had to replace my lug nuts to which I agreed to but damn with just 27,700 miles on the car this is the 6th set of tires and 3rd set of rims.

You’re being shammed.

Have you contacted Ford via the 800# and opened a claim with the Regional CSR? The only way you’re going to get any type of resolution is to get a CSR involved AND an FSE is sent to that Dealer to show the pit monkeys how to understand a NVH analyzer and how to continue with diagnosis.

Also to let you (and others know):
If the vehicle is still under the 3/36, the lug nuts are covered under the 3/36 and should be replaced free of charge! There is also a pending Class Action Suit against Ford for those POS 2-piece lug nuts (there is a thread on here somewhere).

When I had my prior 2016 S550 and was going through then same BS with the driveline vibe (documented in this very thread), Ford replaced all (20) lug nuts under warranty for the same exact issue - deformed exterior caps on the lugs which prevented proper torque of 150 ft-lbs.

—-

As for the NVH readings - I posted my Ford invoices here in this thread where the Tech who worked on my prior 2016 did excellent documentation and put the NVH findings in print. So search my user ID in this thread and you’ll find the extensive posted images of the docs to compare to yours.

If the Tech, the Service Writer, OR the Shop Foreman do not understand HOW to use the NVH Analyzer OR HOW to interpret its results - you’re never going to get anywhere with that facility. Plus if they have not had an FSE on site to assist, again you’re not going to get anywhere with them. This is why you need to contact Ford and get a Regional CSR involved.

OR

Go to another Ford Dealer who has better Tech and Service facilities.

You’re going to find it’s NOT the tires.............. and here’s why:
IF it were tire related, back, front, L or R tires - the vibe would be persistent at ALL speeds and at ANY RPM, period.

——

It is driveline related because IF the NVH occurs only at a certain MPH and RPM, it’s being causing by the revolution of something that is out of balance or damaged. The 2-piece driveshaft, the center support bearing, the rear diff or possibly improper backlash at the front trans flange OR rear diff pinion flange.

Best way to determine, tell and prove to anyone a driveline vibe exists for the DIYers:
Take the car onto the highway, when the vibe starts - lift off the accelerator - the vibe should start to subside as the MPH/RPM decreases. Now do the same again by getting it to the point where it’s vibrating the worst and put the trans into NEUTRAL - the vibe may still be there but not as harsh and will again drop off as MPH/RPM decreases.

Now REPEAT the above, but this time as you get the car to the sweet spot where it starts to vibrate or NVH is present, continue to accelerate UNTIL the vibe rolls off or dissipates, because at some point you’re going to roll through and past the vibe while increasing MPH/RPM.

The most common characteristics of this driveline vibe is it starts to come on from 45-55 mph, is severely present at around 58-67 and starts to dissipate as the vehicle approaches 75-80 mph. Now also give or take 2-3 mph here and there as every vehicle has different tolerances, but within those ranges has been the most problematic and most persistent zones of the driveline NVH being very present.

If the above findings are TRUE during your testing, it’s because when you let off the accelerator OR throw the trans into Neutral, you’re taking load off the driveline - no load and vibe diminishes, apply load and vibe comes back within a certain MPH/RPM.

It’s not freaking tire related IF you can prove the above to ANYONE that has a damn brain functioning under their skullcap.

 

[PipelineEngineer]

So I have gone back to discount tire and replaced the three tires but one of the new tires won't road force balance less than 16 so they volunteered to replace it. The back tires are now less than 12. The car feels smoother and the mirrors don't appear to shake as violently like they did before but both myself and my passenger could feel a vibration in the seat of the car at the exact same speed range before. I will take a look at your information Cobra Jet but I am now looking to just sell the car. Since the mirrors no longer shake the vibration is more annoying than it is a safety hazard.

 

[GT Pony]

So I have gone back to discount tire and replaced the three tires but one of the new tires won't road force balance less than 16 so they volunteered to replace it. The back tires are now less than 12. The car feels smoother and the mirrors don't appear to shake as violently like they did before but both myself and my passenger could feel a vibration in the seat of the car at the exact same speed range before.

What wheels and tires are you running? Did you have the tire shop look for visual run-out of the wheels (without the tires mounted) and also the wheel/tire assembly with the tires mounted?

 

[PipelineEngineer]

I didn't quite understand what you meant by the following but I gave it a try, WOW! As soon as I slipped the car into neutral it reduced to almost nothing in the steering but still felt it in the seat. It is almost like breaking that connection by placing it into neutral prevents the vibration from reaching the front of the car. "
Best way to determine, tell and prove to anyone a driveline vibe exists for the DIYers:
Take the car onto the highway, when the vibe starts - lift off the accelerator - the vibe should start to subside as the MPH/RPM decreases. Now do the same again by getting it to the point where it’s vibrating the worst and put the trans into NEUTRAL - the vibe may still be there but not as harsh and will again drop off as MPH/RPM decreases."

 

[Cobra Jet]

I don’t know if it’s been posted in this thread yet or not, but here is Ford SSM 47991:

 

[LumenCordis]

I forgot all about his thread, as I got rid of my mustang and the last ford I'll ever buy nearly 3 years ago. After multiple attempts bringing my car in and being told I wasnt going to get help. And being told by my ford service managers I should buy a camaro or a challenger. After a year long lawsuit and arguing it out in arbitration with the ford scumbag attorney. I did in fact buy a camaro, and I have not looked back, best decision I could have made.

 

[hlh1]

I forgot all about his thread, as I got rid of my mustang and the last ford I'll ever buy nearly 3 years ago. After multiple attempts bringing my car in and being told I wasnt going to get help. And being told by my ford service managers I should buy a camaro or a challenger. After a year long lawsuit and arguing it out in arbitration with the ford scumbag attorney. I did in fact buy a camaro, and I have not looked back, best decision I could have made.

I'm sorry to hear it got to this. I just traded in my 17gt for a 19GT to solve the vibration problem.

 

[gmupatriot]

I'm sorry to hear it got to this. I just traded in my 17gt for a 19GT to solve the vibration problem.

I have a early built 2018 Mustang GT (nov 2017) and it developed the vibration around 1200 miles. I am at 33,000 miles now and the vibration is always there. It starts at 55mph and goes away (or is no small that I cannot differentiate between that and road feel) around 70mph and comes back around 85-90 mph. It is really annoying because the car vibrates, the rear view mirror vibrates and it really takes away the fun of driving it over any amount of long distance trip.

 

[hlh1]

I thought they had the issue resolved on the 18's and up. Guess not!

 

[ABS550]

I have a early built 2018 Mustang GT (nov 2017) and it developed the vibration around 1200 miles. I am at 33,000 miles now and the vibration is always there. It starts at 55mph and goes away (or is no small that I cannot differentiate between that and road feel) around 70mph and comes back around 85-90 mph. It is really annoying because the car vibrates, the rear view mirror vibrates and it really takes away the fun of driving it over any amount of long distance trip.

Read these two posts. I solved my vibration in my own driveway in an afternoon.
First get the app to see if your vibration is at a frequency that could be explained by a driveshaft imbalance. ( I think the app was $5 or $6 at the time)
Page 118, post 1767
Page 119, post 1773

My car has now been vibration free for 3-1/2 years and I enjoy every minute behind the wheel!
Never had the dealer look at it. Never looked back. It is a shame that some have had to go to extremes for months to get satisfaction or in some cases, no satisfaction.

Cheers, Blake.

 

[gmupatriot]

Read these two posts. I solved my vibration in my own driveway in an afternoon.
First get the app to see if your vibration is at a frequency that could be explained by a driveshaft imbalance. ( I think the app was $5 or $6 at the time)
Page 118, post 1767
Page 119, post 1773

My car has now been vibration free for 3-1/2 years and I enjoy every minute behind the wheel!
Never had the dealer look at it. Never looked back. It is a shame that some have had to go to extremes for months to get satisfaction or in some cases, no satisfaction.

Cheers, Blake.

Thank you!! I will have to take it to my local mechanic with these instructions. I live in an apartment so I do not have the permission or place to work on this issue.

 

[ABS550]

Thank you!! I will have to take it to my local mechanic with these instructions. I live in an apartment so I do not have the permission or place to work on this issue.

No problem. Remember, you should get an "Audio Spectrum Analyzer" app and use it while driving at the speed when the sound or vibration is MOST noticeable. For me, I heard a deep rumble which was at it's worst at 68 mph. The sound that my iPad could hear above any other sound was a 48Hz sound. (the deep rumble) I did some math and figured out that with my gearing etc, the driveshaft turns at almost exactly 48 times per second while driving at 68 Mph, so the driveshaft made sense for me to look at.

 

[PipelineEngineer]

I am quoting a post I made else where on the forum. I have discovered and confirmed I have two vibration issues. One is the tires (all speeds but especially prevalent at low speed cold temps) , the other is drive shaft related.

"I am now on my third set of Continental DWS-06 tires in two years and less than 5k miles. I originally bought them due to reading all the forms and good reviews. However, these tires have been nothing but an absolute migraine for me on a car I maybe drive 4-5x a month. Compounding this migraine was because the issue appeared around the same time I began developing a vibration issue with my drive shaft (LONG story but we [Discount Tire/Firestone/Ford] eventually discovered I have two independent vibration issues). Every set of these DWS-06 tires we have put on this car seem to develop flat spots if (1) it sits more than a few days or (2) it gets really cold out. Sometimes when the tires warm up they partially come out but other times they won't and the tire will never again road force balancing below 30. Due to the events that happened leading up to this our finding and data has been well documented and believe we have identified that the issue may lie with the chemistry of the tire and will be getting in touch with Continental to communicate our results. That said, where do I look for a tire that wont do this? Having spent a lot of time in the waiting room/counters of these place I have been told this comes a surprise to them because this is something they more commonly see with other tire manufactures. Oddly enough I was told specifically they have been seeing this issue a lot with the new Michelin Pilot Sport tires.... So now I don't know where to turn because with every other vehicle I have ever owned Michelin had been the only brand that never let me down."

 

[hlh1]

The Pilot Sport tires on my 19 GT PP1 have been great with no problems.

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