Vibration between 50 & 70 mph

Jackhammer said:

I just purchased a new 2017 Mustang GT Premium 6 speed over the weekend. Before I bought it I took it on a test ride, but it was under 50 mph.
I will drive this car as my daily driver and it will be driven on average 1000 miles per week.
Today was my first day using the car and I noticed a lot of drivetrain vibration between 60-70 mph.
I can’t believe it. If I knew about this vibration problem, I wouldn’t have purchased this car.
I have had many Mustang GT’s and Super Duty pickups and I never had a problem like this.
I mean come on, it’s 2017 and Ford can’t build a IRS car that doesn’t have driveline vibration??
Absolutely ridiculous.
I’ll call the dealer tomorrow, but if they can’t fix it I’ll get rid of it and buy a Challenger Scat Pack 392. I heard those are really smooth with no vibrations.
Since I’m on the highway constantly, I can’t live with a vibration like this. Too annoying.
Oh well. What can you do.

Jack

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For a highway DD, you will love the Challenger. Bigger, smoother, quieter, better seats, uconnect that blows away sync, etc. After 1.5 years of fighting Ford on my Mustang, I cut my losses and traded for the Challenger. Life's too short to be pissed off all the time...

speedfrk said:

For a highway DD, you will love the Challenger. Bigger, smoother, quieter, better seats, uconnect that blows away sync, etc. After 1.5 years of fighting Ford on my Mustang, I cut my losses and traded for the Challenger. Life's too short to be pissed off all the time...

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I checked out the Camaro 2SS (LOVED the engine and standard trans was unbelievable! but visibility probs, tiny trunk, 100% unusable back seats unless you are 5 years old - forget it)

I liked the Challenger but didn't try it because it's too big and the styling - to me - was bland.

Maybe next generation of Challenger will be more to my taste.. So far my Mustang has been amazing but I'm only 6,000 miles in.

usgiorgi said:

You're gonna love the 392. In my opinion it's a true muscle car engine compared to the coyote. The 5.0 feels like a sports car where you have to wind out the engine to get any decent power. With the scat pack, it's instant torque. Just need some big tires. With stickies you can get 3.9 sec 0-60.

I was tired of ford jerking me around, so I got the charger scat pack. No regrets. I'm just on here giving advice to people going through the same issues as I went through

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Ditto for me, except I went for the whole enchilada & got a Hellcat.
Been a year now since I made the switch & I'm happy with my decision.
There has been zero down time on the Cat vs. the 80+ days my GT was out of service (with no resolution to the vibration).

We decided to replace one of our other vehicles with an SUV & picked up a new Durango R/T (with the SRT hood & front end!!) last week. Would have gotten an Explorer if Ford had actually showed any interest & expertise in addressing my GT issues, but I simply no longer trust them.

Hellcats are SWEET! Out of my snack bracket though

fwiw, i've been battling a driveline vibration.

note that my car is highly modified, but the steps i took to resolve the issue are probably still valid for a stock car.

first, the relevant drivetrain-related setup. '15 gt manual, 1pc aluminum dynotech driveshaft, aluminum diff carriage, poly diff mounts, delrin subframe mounts, poly motor mounts, ati harmonic balancer, mcleod rst clutch, mcleod lightened steel flywheel.

so obviously, there's already a lot of lighter components in the driveline, and a lot less compliance than it came with from the factory. first noted the vibration after installing the driveshaft, becoming noticeable around 70mph, increasing substantially with speed (never took it past 80mph, car was vibrating extremely harsh).

step 1: re-installed stock 2pc driveshaft. vibration gone. not an acceptable solution though so..

step 2: re-installed and rotated the 1pc driveshaft at the pinion flange 180deg from where it had been previously installed. seemed to improve initially, but quickly came back (not as bad though).

step 3: spaced the transmission mount down 0.25". more improvement, but significant vibration still, especially in excess of 80mph.

step 4: removed motor mount spacers (dropping engine 0.5"). vibration gone, slight harmonic resonance above 70mph.

to remove the audible pulsating resonance, i plan to try the clamp trick noted throughout this thread and report back. but in terms of vibration elimination, it's about as good as i think i'll be able to get it given the ancillary components in my drivetrain.

for those struggling through this issue, it may be worth your while to try some of these things to see if they help.

So all these cars have motor mount spacers?

Dominant1 said:

So all these cars have motor mount spacers?

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no, i swapped on some BMR MM007 mounts when i rebuilt my engine, and kept it at stock height - but (2) 1/4" spacers can be removed. pic from BMR for reference:

I had my vibration down to a level I could live with, but had to tweak it a little more. I ended up placing 1 of the washer plates the go under two pinion flange bolts as close to the light side of the driveshaft as possible. That small amount of weight eliminated my vibration completely. So I now have 4 of those plates installed. Three in normal position and the fourth doubled at the light side of the shaft.
One hose clamp would have been too heavy. In my situation I was able to completely correct this issue, but it has been a lot of trial and error, careful documentation of what I did so as not to repeat anything, and a lot of patience. Don't give up.

^^Do you have a pic of this?

CNCLester said:

That small amount of weight eliminated my vibration completely.

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I believe it. It's amazing how little weight it takes to cause a felt vibration. The S550 chassis is basically an antenna for driveline issues, with the receiver being the driver seat and rear view mirror.

It just Proves what Kelly at Bmr has been saying all along: the drive line angles on these cars are fubar from the factory and if you want it fixed you have to fix it yourself!!!! I got mine to where its tolerable, about 95% of the vibes i had are gone just looking what could take it to %100 gone...... only thing i did was flip my dynotech ds 180 degrees and added .25" cross member spacers....

CNCLester said:

I had my vibration down to a level I could live with, but had to tweak it a little more. I ended up placing 1 of the washer plates the go under two pinion flange bolts as close to the light side of the driveshaft as possible. That small amount of weight eliminated my vibration completely. So I now have 4 of those plates installed. Three in normal position and the fourth doubled at the light side of the shaft.
One hose clamp would have been too heavy. In my situation I was able to completely correct this issue, but it has been a lot of trial and error, careful documentation of what I did so as not to repeat anything, and a lot of patience. Don't give up.

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I am not having any luck with mine at all. I did the transmission spacers trick and it made zero difference. Trying the clamps on what is now my 3rd factory driveshaft and no luck either so I would love to see what it is you are referring to as I am not understanding what you did but would love to try it
Thanks in advance

Here is one of the washer plates I'm talking about. You have 3 of them stock. They are available at Ford dealer but only as an assembly with 2 bolts. It's about 5 dollars.
I'm having trouble uploading photo now. I'll get one loaded Tonite.

as far as i know The spacers don't work on stock driveshafts they work on one piece Ds's !

Well I am putting my car back to stock and letting Ford have at it again. awhile they have it I am sending the Lemon Law papers in as it already qualifies
I didnt pay almost $40k for a car that I have to fix for Ford.