Vibration between 50 & 70 mph

[Arcadia]

I have been experiencing rumbling & vibration between 50 & 70 mph, which kind of felt like the wheels were out of balance. After rebalancing them twice, the dealer even tried a different set of wheels & tires - no luck.

They now believe that the drive shaft needs replacing - at 1100 miles. :frusty:

Anyone else experiencing this?

i have it on mine - 58 mph is where it is really vibrating. Dealer said balanced tires and still there. Checked other mustangs on lot and mine much worse. They believe they have narrowed down to lower control arms - we shall see. Parts on order.

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[Cobra Jet]

i have it on mine - 58 mph is where it is really vibrating. Dealer said balanced tires and still there. Checked other mustangs on lot and mine much worse. They believe they have narrowed down to lower control arms - we shall see. Parts on order.

@Arcadia
I don’t want to be the one to say this, but it’s not going to be lower control arms... and that Dealership needs to assign one of their Lead Techs to the car.

Here’s why I’m saying this:

If the “vibe” is presenting itself at certain speeds, it’s driveline related NOT suspension related.

If the “vibe” can be replicated OR presents itself only at certain RPM or MPH, again it’s driveline related and NOT suspension related.

If you can get the car up to 58mph where it vibes the most and you:
1) let off the accelerator and let the car decrease in momentum OR put the car in neutral and the vibe diminishes
2) accelerate past the vibe (somewhere in the 65-70+ zone) and the vibe diminishes
it’s the driveline and NOT the suspension.

Trust me and the others who have extensive experience and knowledge of the problem (and those who have posted great tech of DIY diagnosis and repairs in this very extensive thread). The Dealership is wrong in trying to diagnose lower control arms as being the vibration issue... If control arms were bad, or the bushing inserts were bad, there would be additional NVH characteristics. The vibe would not be MPH or RPM related, nor would it “come and go” through MPH or RPM ranges; there also would be additional noises present at any MPH at any RPM and more prevalent on uneven or deteriorated road surfaces.

The best advice I can give you:
Take the Shop Foreman or Lead Tech on a test drive with YOU driving. Get the car up to the sweet spot where the problem is most pronounced and make sure the Tech obliges that he can feel the NVH and vibration. Then let the Tech drive it back to the shop and tell him to hit the same mark so he can experience it from the driver’s seat. That’s the only way to make sure the Tech knows and acknowledges there is a problem.

 

[Jackhammer]

I wonder if this flange would help.

https://lmr.com/item/M4851M8A/mustang-ford-performance-automatic-irs-pinion-flange-15-18

 

[synthwave_s550]

Hey guys, new Mustang owner here. I just bought a used 2017 Grabber Blue Ecoboost premium convertible. Car has 45k miles, so still within factory powertrain warranty. The car had a baaaaaaddd vibration from 50-70, literally the front passenger seat was shaking.

I took the car into the local Ford Dealer (Ted Britt in Chantilly) for TSB SSM 45938. After throwing 4 new tires at it and road force balancing them, they agreed to replace the driveshaft. While the vibration is much much better, it's still there and still very much annoying.

My vibration seems to show up at all speeds from 20 mph forward, and it's on and off...I can cruise at the same speed and the vibration will come and go. But it's definitely there and felt the most in the rear floor of the car.

Selling the car is not a favorable option at this time, as I went to considerable lengths to get it (grabber blue verts are hard to find), so I plan on throwing various parts at the problem until I can correct it. I have read through a lot of threads, and it seems like there is not a one-size-fits-all solution which makes this super annoying. Hoping I can learn from you guys which way I should go next...is it worth continuing to try and get the dealer to fix it?

 

[Arcadia]

@Arcadia
I don’t want to be the one to say this, but it’s not going to be lower control arms... and that Dealership needs to assign one of their Lead Techs to the car.

Here’s why I’m saying this:

If the “vibe” is presenting itself at certain speeds, it’s driveline related NOT suspension related.

If the “vibe” can be replicated OR presents itself only at certain RPM or MPH, again it’s driveline related and NOT suspension related.

If you can get the car up to 58mph where it vibes the most and you:
1) let off the accelerator and let the car decrease in momentum OR put the car in neutral and the vibe diminishes
2) accelerate past the vibe (somewhere in the 65-70+ zone) and the vibe diminishes
it’s the driveline and NOT the suspension.

Trust me and the others who have extensive experience and knowledge of the problem (and those who have posted great tech of DIY diagnosis and repairs in this very extensive thread). The Dealership is wrong in trying to diagnose lower control arms as being the vibration issue... If control arms were bad, or the bushing inserts were bad, there would be additional NVH characteristics. The vibe would not be MPH or RPM related, nor would it “come and go” through MPH or RPM ranges; there also would be additional noises present at any MPH at any RPM and more prevalent on uneven or deteriorated road surfaces.

The best advice I can give you:
Take the Shop Foreman or Lead Tech on a test drive with YOU driving. Get the car up to the sweet spot where the problem is most pronounced and make sure the Tech obliges that he can feel the NVH and vibration. Then let the Tech drive it back to the shop and tell him to hit the same mark so he can experience it from the driver’s seat. That’s the only way to make sure the Tech knows and acknowledges there is a problem.

Thanks for the good info! Dealer never did not acknowledge the issue and even went so far as to compare other new 2020 cars on lot to verify that the vibration was not normal. I did bring in some info from this thread and discussed with them but they wanted to do the lower control arms first and did find some issues. After the change they confirmed the vibration issue had not been resolved and did the below repairs. I can confirm that the vibration appears to be complete gone now at speeds of 50-85mph.

 

[exhausting1]

Posted this in another thread and was asked to post it here.

Greetings everyone, Newbie here to your forum. I do not own a Mustang, however I do own a 6R80 transmission out of a 2016 Mustang Ecoboost car. I have a 1937 Ford. A complete Fatman Chassis with coilover suspension, adjustable shocks, Disc brakes etc. The engine is a 2.0Ecoboost from Ford Performance that has the turned up factory tuned computer that is not available anymore. I see 23-24lbs of boost and it is rated at 350ftlbs of torque. The 6R80 is controlled by a Quick6 controler, works great. The first gearbox had about 15000 miles on it when I got it. On first driving of the car there was a "minor" vibration at about 65mph and would lessen as speed got higher! Changed the final gear in the 9inch rear end .25 points higher and kicked the vibration up to about 73-78 mph, so the issue was definitely from the tranny back, eh?
I have both a two piece driveshaft and a one piece. I have worked every angle on engine, (as I can vary that), the differential (using angled shims) and intermediate angles on the two piece shaft. Nothing I do will change it except make it worse.
I have machined the output flange to make sure it runs true to the output shaft. the shafts have been balanced a couple times each.
When the original tranny I had started dropping into 3rd gear while on the highway, uugghh! and after changing out the Ford redesigned plastic wire connection piece( I forget the name of it) which also houses the output shaft rpm counter which was the main issue, I realized the problem with the driveshaft is related to the output rpm sensor gettng trashed also.
The 6R80 as configured for the Mustangs (at least the Ecoboost) utilizes a output shaft "bushing" which is part of the housing. I believe it is a steel sleeve that is pressed into the housing itself. The entire output shaft is relatively short and while held in the front by a bearing captured into a dear drum, the distance between them is very short which means the shaft is not supported well enough for the loads it sees from the driveshaft. It is a known issue among transmission re-builders as there exists a aftermarket sleeve, apparently made from a "better" material for the job. I have also found out that even a rebuilt or re-manufactured transmission will not necessarily have this issue addressed.
Make a long story shorter, it was possible to grab the front of the driveshaft and move the output shaft up and down maybe as much as .25"! I purchased a "remanufactured" tranny from Jasper,(not cheap) . The output shaft was probably half as much "slop" in the new tranny. I figured they did not address the output bushing, but it was a lot better, ok? Driveshaft vibration was reduced by a noticeable amount. Ok, so my hunches are probably correct. The bearings or bushings holding the output shaft are not good enough, the shaft is too short and not supported properly for the job. The busings will wear out prematurely which is why some folks get the vibration with more miles verses a box which is bad from the factory or wears out faster than another.

Want further proof? I also have noticed that if I get to the highway in like less than 5 minutes there is no vibration. Okay, after driving for maybe another 10 minutes and the vibration returns.... so the issue is as the transmission warms up and gets hotter the "bushing" holding the back of the output shaft grows bigger (not good) with the expanding aluminum case and allows the driveshaft to whip around.

I understand a few Pickup trucks have this issue also.

It is not hard for me to see why Ford will not address this issue as it "is" a design flaw, (IMO) and the real fix is to refit a better bushing at the rear of the case but the problem is the wnitre transmission has to come apart. Not cheap, right? There ya go.

I will be playing with the hose clamp fix to see if I can counter balance the "whipping". I am keeping my fingers crossed.

Link to article in "FrontStreet" mag. https://frontstreet.media/2019/10/18/this-1937-ford-ecoboost-tudor-humpback-breaks-all-the-rules/
Calvin

 

[exhausting1]

Posted this in another thread and was asked to post it here.

Greetings everyone, Newbie here to your forum. I do not own a Mustang, however I do own a 6R80 transmission out of a 2016 Mustang Ecoboost car. I have a 1937 Ford. A complete Fatman Chassis with coilover suspension, adjustable shocks, Disc brakes etc. The engine is a 2.0Ecoboost from Ford Performance that has the turned up factory tuned computer that is not available anymore. I see 23-24lbs of boost and it is rated at 350ftlbs of torque. The 6R80 is controlled by a Quick6 controler, works great. The first gearbox had about 15000 miles on it when I got it. On first driving of the car there was a "minor" vibration at about 65mph and would lessen as speed got higher! Changed the final gear in the 9inch rear end .25 points higher and kicked the vibration up to about 73-78 mph, so the issue was definitely from the tranny back, eh?
I have both a two piece driveshaft and a one piece. I have worked every angle on engine, (as I can vary that), the differential (using angled shims) and intermediate angles on the two piece shaft. Nothing I do will change it except make it worse.
I have machined the output flange to make sure it runs true to the output shaft. the shafts have been balanced a couple times each.
When the original tranny I had started dropping into 3rd gear while on the highway, uugghh! and after changing out the Ford redesigned plastic wire connection piece( I forget the name of it) which also houses the output shaft rpm counter which was the main issue, I realized the problem with the driveshaft is related to the output rpm sensor gettng trashed also.
The 6R80 as configured for the Mustangs (at least the Ecoboost) utilizes a output shaft "bushing" which is part of the housing. I believe it is a steel sleeve that is pressed into the housing itself. The entire output shaft is relatively short and while held in the front by a bearing captured into a dear drum, the distance between them is very short which means the shaft is not supported well enough for the loads it sees from the driveshaft. It is a known issue among transmission re-builders as there exists a aftermarket sleeve, apparently made from a "better" material for the job. I have also found out that even a rebuilt or re-manufactured transmission will not necessarily have this issue addressed.
Make a long story shorter, it was possible to grab the front of the driveshaft and move the output shaft up and down maybe as much as .25"! I purchased a "remanufactured" tranny from Jasper,(not cheap) . The output shaft was probably half as much "slop" in the new tranny. I figured they did not address the output bushing, but it was a lot better, ok? Driveshaft vibration was reduced by a noticeable amount. Ok, so my hunches are probably correct. The bearings or bushings holding the output shaft are not good enough, the shaft is too short and not supported properly for the job. The busings will wear out prematurely which is why some folks get the vibration with more miles verses a box which is bad from the factory or wears out faster than another.

Want further proof? I also have noticed that if I get to the highway in like less than 5 minutes there is no vibration. Okay, after driving for maybe another 10 minutes and the vibration returns.... so the issue is as the transmission warms up and gets hotter the "bushing" holding the back of the output shaft grows bigger (not good) with the expanding aluminum case and allows the driveshaft to whip around.

I understand a few Pickup trucks have this issue also.

It is not hard for me to see why Ford will not address this issue as it "is" a design flaw, (IMO) and the real fix is to refit a better bushing at the rear of the case but the problem is the wnitre transmission has to come apart. Not cheap, right? There ya go.

I will be playing with the hose clamp fix to see if I can counter balance the "whipping". I am keeping my fingers crossed.

Link to article in "FrontStreet" mag. https://frontstreet.media/2019/10/18/this-1937-ford-ecoboost-tudor-humpback-breaks-all-the-rules/
Calvin

Fianlly got to work with the Hose clamps on the driveshaft. Marked the front of the shaft in quarters numbered 1,2,3 and 4. Started with 2 clamps with the screw part at # 1. Drove car at speed and thought it might be a little better. Moved the cplamps to position # 2, drove again and the vibration is gone. Made a coouple more minor movements of the clamps to no difference so I am very happy at this point.

Let me be clear here. I have been at this for over a year. This shaft in particular has been balanced twice just to be sure. Understand that to balance a driveshaft both ends are held fixed in a fixture that is concentric and does not "run out" at all. The angles are perfect on both the trans and differential. Tires are perfectly balanced and run up on a high speed balancer also. There is nothing to point to but the tailshaft on the 6R80 running out, ie, not held strong enough to overcome the forces working in the driveshaft and car...
Adding weights in the proper place on the driveshaft has balanced out the entire system which is impossible to do at a driveshaft shop.

 

[Cobra Jet]

Just another FYI that may help S550 owners. Stumbled across this thread tonight which I’ve never come across, seems some vibrations could be tied to engine sitting too low over k-member.

https://www.mustang6g.com/forums/threads/massive-drivetrain-vibration.98651/#post-2159247

 

[Blufc3s]

I CURED MY VIBRATION!!!!!!!!!!!!!! Here's what did it and the method I used:

1) Installed Steeda cradle bushing supports and diff bushings (red). This made it better, but not completely eliminated.
2) Did a DIY on-car balance of my driveshaft. Below I'll explain the background and method for what I did...

As a home shop machinist, I often have need to balance grinding wheels for my surface grinder. The grinding wheel hubs have two movable balance weights that can be used to adjust both the location AND the magnitude of the counterbalance. I used a similar method on my driveshaft using two hose clamps as counterweights.

Use only premium quality hose clamps: US made, Stainless Steel. Unfortunately I don't remember what size I used. But that's easy for you to figure out on your own.

1) Safely raise the back end of the car so the rear wheels can spin freely. Safely is the key word here...
2) Turn traction control off and slowly increase speed until your hear/feel peak vibration. Note the speed at which this occurs.
3) Now, install one of the two hose clamps onto the driveshaft back by the pinion flange.
4) Repeat step 2, the vibration will likely be worse.
5) Turn off the car and loosen the clamp and rotate it about 30 degrees.
6) Repeat steps 4 and 5 until you get minimum vibration at the same speed.
7) Now fine tune the position with very small movements. Once done, you will have located the light side of the driveshaft and the screw assembly on the clamp is acting as a counterweight. If the vibration is gone, you're done: tighten the clamp securely and grab a beer.
8) Now install a second hose clamp next to the first one lined up exactly the same. The screws should both be facing the same way.
9) Using a permanent marker, create a match mark between both hose clamps and the driveshaft. Just draw a straight line crossing the band portion of the clamps and the driveshaft.
10) The next step will be to adjust the amount of counterweight needed to achieve no vibration (assuming two hose clamps are enough). Again run the car on jack stands and note the vibration. If the vibration is gone, you're done: tighten the clamp securely and grab a beer.
11) Loosen both clamps and rotate them slightly in opposite directions so that each is moved by the same amount: this is important. Use the mark on the driveshaft you made in 9 as a reference. The lines on each clamp band should always be symmetrical about the line on the driveshaft.
12) Run the car and note vibration.
13) Repeat steps 11 and 12 rotating each clamp a little at a time until the vibration is eliminated...

Now, don't fret about hose clamps on your driveshaft. They will stay put. Furthermore, if Ford uses their analyzer to do an on car balance, they will use hose clamps. As an added measure, you can always stake them with epoxy...

Cheers!
John

I would like to say how grateful I am for this post!
My car has had a vibration, the dealer replaced the DS under warranty, and it didn’t cure the problem, which was between 80 and 115 Kmph. It occurred with the car in neutral cruising at these speeds, so I still suspected the DS or a half shaft.
I used the hose clamp as suggested and after a few attempts the vibration is totally gone except for about a 2-3kmph range, which, if I wasn’t looking for it I probably wouldn’t notice. I’ve done this using 1 clamp, but I may try to tweak it in the future using 2 clamps.
Thanks again, I was seriously thing of buying a 2020 A10 as the vibration bothered me so much.

 

[888mustang]

Fianlly got to work with the Hose clamps on the driveshaft. Marked the front of the shaft in quarters numbered 1,2,3 and 4. Started with 2 clamps with the screw part at # 1. Drove car at speed and thought it might be a little better. Moved the cplamps to position # 2, drove again and the vibration is gone. Made a coouple more minor movements of the clamps to no difference so I am very happy at this point.

Let me be clear here. I have been at this for over a year. This shaft in particular has been balanced twice just to be sure. Understand that to balance a driveshaft both ends are held fixed in a fixture that is concentric and does not "run out" at all. The angles are perfect on both the trans and differential. Tires are perfectly balanced and run up on a high speed balancer also. There is nothing to point to but the tailshaft on the 6R80 running out, ie, not held strong enough to overcome the forces working in the driveshaft and car...
Adding weights in the proper place on the driveshaft has balanced out the entire system which is impossible to do at a driveshaft shop.

 

[888mustang]

I do like your theory of the trans bushing and you may be right. But I just want to point out that this happens on cars with a M82 manual trans. My car had the vibration and the Dealer tried an new drive shaft ,it made no difference. I fixed mine by changing the clock position were the drive shaft mounts to rear diff. Different positions made a huge difference on my car.

 

[Stang 19]

I have been experiencing rumbling & vibration between 50 & 70 mph, which kind of felt like the wheels were out of balance. After rebalancing them twice, the dealer even tried a different set of wheels & tires - no luck.

They now believe that the drive shaft needs replacing - at 1100 miles. :frusty:

Anyone else experiencing this?

My 2011 GT 6 speed manaul PP1 with 3.73 gears. Dealer ended up up pulling the complete rear axle from a brand new stang on their lot and installing in my car. Problem solved for me.

 

[J17GT]

My turn to post in this thread. I picked up my 2017 GT April 2019. Purchased it private party from the original owner about 5 hours away from me. Car was 100% stock and I took it on a short test drive. All checked out so we made the deal.

Five hour drive home, I notice a bit of a buzz in the car at highway speed. The rear view mirror would vibrate, steering wheel, even feel it in the seat. Get home and did some searching and was instantly overwhelmed by this thread. Haha!

I enjoyed the car all last summer and just ignored it, but it did start to wear on me. This year covid screwed everything up and I wasn’t using the car much. I finally decided to take it to the dealer a month ago and have them look at it. I did take note of the DIY suggestions offered here, but figured I’d let the dealer look at if first.

They put it on their NVH machine and it said “unknown vibration.” Just perfect! I give them credit, they kept digging and poked around everything moving under the car. They told me the rear diff housing was buzzing / vibrating like crazy. I was really suspect of that diagnoses, but didn’t argue it. I even mentioned the driveshaft balance to them, but they said the rear end was vibrating so much it had to be it.

Took a full month to get the parts. New torsen diff, ring & pining, bearings etc. The whole rear end rebuild kit. I was super anxious and annoyed it took so long. I picked up the car this week and it’s FIXED. The car is SMOOTH AS GLASS. I am totally surprised honestly. Completely worth a month without the car for it to finally be right. Feels like a different car now.

I just wanted to post my experience. Now time for a whipple kit this winter!!

 

[GT Pony]

They put it on their NVH machine and it said “unknown vibration.” Just perfect! I give them credit, they kept digging and poked around everything moving under the car. They told me the rear diff housing was buzzing / vibrating like crazy. I was really suspect of that diagnoses, but didn’t argue it. I even mentioned the driveshaft balance to them, but they said the rear end was vibrating so much it had to be it.

Took a full month to get the parts. New torsen diff, ring & pining, bearings etc. The whole rear end rebuild kit. I was super anxious and annoyed it took so long. I picked up the car this week and it’s FIXED. The car is SMOOTH AS GLASS. I am totally surprised honestly. Completely worth a month without the car for it to finally be right. Feels like a different car now.

Sounds like the dealership was methodical in their trouble-shooting and zeroed in on the root cause. Lucky you found a dealer that had excellent Techs who knew how to use the NVH machine and find the vibration source.

 

[CEHollier]

My turn to post in this thread. I picked up my 2017 GT April 2019. Purchased it private party from the original owner about 5 hours away from me. Car was 100% stock and I took it on a short test drive. All checked out so we made the deal.

Five hour drive home, I notice a bit of a buzz in the car at highway speed. The rear view mirror would vibrate, steering wheel, even feel it in the seat. Get home and did some searching and was instantly overwhelmed by this thread. Haha!

I enjoyed the car all last summer and just ignored it, but it did start to wear on me. This year covid screwed everything up and I wasn’t using the car much. I finally decided to take it to the dealer a month ago and have them look at it. I did take note of the DIY suggestions offered here, but figured I’d let the dealer look at if first.

They put it on their NVH machine and it said “unknown vibration.” Just perfect! I give them credit, they kept digging and poked around everything moving under the car. They told me the rear diff housing was buzzing / vibrating like crazy. I was really suspect of that diagnoses, but didn’t argue it. I even mentioned the driveshaft balance to them, but they said the rear end was vibrating so much it had to be it.

Took a full month to get the parts. New torsen diff, ring & pining, bearings etc. The whole rear end rebuild kit. I was super anxious and annoyed it took so long. I picked up the car this week and it’s FIXED. The car is SMOOTH AS GLASS. I am totally surprised honestly. Completely worth a month without the car for it to finally be right. Feels like a different car now.

I just wanted to post my experience. Now time for a whipple kit this winter!!

Glad the problem was solved. Mine was the drive shaft/U joint. Once fixed smooth as glass.

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