Vibration between 50 & 70 mph

Washer plate - acts as washer under the factory pinion yoke bolts. My GT only had two plates - 6 holes for 6 pinion yoke bolts. 2nd pic is the end of the stock driveshaft (top) compared to Shaftmasters (middle) and Dynotech (bottom) ends. The thickness of these DS ends also screams the importance of making sure both the pinion yoke and DS end mating surfaces are super clean and super flat without burrs, loctite, etc.

Thanks for posting that. My plates only go on two bolts. I just got lucky and found the perfect combination of components for my car. I love the car and refused to give up. I do however fully understand anyone dropping 40k plus on a preimum being really upset. I bought a base at 6k off sticker and really good money on my old diesel truck in trade. I'm in the car really good. Ford should never have let this happen. It does seem to fall in line with the founder's arrogance however. I hope what worked for me helps someone else.

CNCLester said:

Thanks for posting that. My plates only go on two bolts.

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Interesting that both our cars are '17 models and have different DS components. Seems like Ford is making some effort at changing things. :shrug: Maybe if your car is not a PP, that may make the difference.

Lugz, if you read my earlier posts, you will see that I bought a shaftmasters one piece shaft, a torsen iron case differential from a local club member, and 4.09 gears from Ford racing, and BMR differential lock out kit. I put all this on the car and still had vibe. Trial and error found the proper balance. Ford has done nothing.

CNCLester said:

Lugz, if you read my earlier posts, you will see that I bought a shaftmasters one piece shaft, a torsen iron case differential from a local club member, and 4.09 gears from Ford racing, and BMR differential lock out kit. I put all this on the car and still had vibe. Trial and error found the proper balance. Ford has done nothing.

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Glad you got yours straightened out. I tried the shaftmasters DS, but I got tired of trying to get the vibe out of it. The dynotech one wasn't perfect but better than SM. I monkeyed with the balance for several hours, did the trans xmember shims, and got it to 99% good. Just installed the BMR CB005 over the weekend, which didn't do much for my wheel hop but may have cured the last 1%. I'll know more on Thursday when I get it out on the highway for a longer drive. Oddly my stock DS was glass smooth. Wanted the weight and rotating mass reduction, but in hindsight I should have just left the stocker in since this has been a bit of a headache. :headbonk:

BTW, don't mean to malign the SM shaft. It's a beautiful piece and their support and return policy was fantastic... wish I could say the same about Dynotech, which doesn't seem to care if you're happy with their product or not.

Dominant1 said:

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....

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I don't think so because there are some that did not have this problem. If it was a design issue they all would. Seems like its happening on various equipment packages and models including the V6 but my V6 didn't have it and it had the same parts.

The CB005 and vertical links are my next mod after some wider sticky tires. Hopefully your issue clears up as well. I'm interested to see what geometrical differences are present on th 2018 mustang. I thought I read somewhere some changes have been made. If so I bet Ford will still leave us in the DIY zone. Would be nice if at least the differential and pinion angles were within 1 degree.

so i took in my car today a 2017 mustang gt automatic with 6k miles on it, to the dealership. It already had 2 driveshafts replaced but i still experience vibration around 75 miles an hour. The shop foreman tried to say it could be the aftermarket wheels and i told him that i just had them rebalanced and that I had the exact wheels on my previous ecoboost mustang with no issue. I have an appointment to take it back in on thursday. this will be the third time I take in for the same problem. What do you guys think should I do? Lemon Law?

NothernVAMustang said:

so i took in my car today a 2017 mustang gt automatic with 6k miles on it, to the dealership. It already had 2 driveshafts replaced but i still experience vibration around 75 miles an hour. The shop foreman tried to say it could be the aftermarket wheels and i told him that i just had them rebalanced and that I had the exact wheels on my previous ecoboost mustang with no issue. I have an appointment to take it back in on thursday. this will be the third time I take in for the same problem. What do you guys think should I do? Lemon Law?

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Tell them to take a set of compatible wheels off a new vehicle on their lot, install them on your car and then see if the vibe is or is not there. It's NOT a tire or rim issue - it's something inherent with either the POS parts being supplied by the vendor contracted to make X-driveline parts or there is an issue in manufacturing of the vehicle driveline mounting areas and/or tolerances such as back lash, rotating mass, etc.

This driveline vibe issue has been well documented in the film called "A Faster Horse" and to date, it's pretty damn ignorant of Ford having no real fix well into the 2017 models.

I'd like to know what the physical differences are between the original driveshaft and the now "new" replacement being used from the most recent SSM 46767. Does anyone know??

15Pony said:

I don't think so because there are some that did not have this problem. If it was a design issue they all would. Seems like its happening on various equipment packages and models including the V6 but my V6 didn't have it and it had the same parts.

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The only version of our mustangs I've never heard a complaint from is the gt-350, but with what ford had to go thru balancing that flat plane v-8 i guess they got it right....

Update on where I am at. After playing with the hose clamp position, I was unable to get any further in vibration/sound reduction on this issue. Again, it made the vibe pretty much gone at 50 to 79, 80 and above would get louder. I had also lowered the Trans mount 1/4" and that did not do anything for me.

Before getting too aggressive on the MODS to fix the issue myself, I decided I'll take it back to stock and at least see if the dealer will look it over with the TSB in mind. I was told to kick a rock last time..... This time I am told the shop foreman will be driving / looking at it. Everyone at dealership nice about it all, so lets hope they really care enough to do a real diagnostic.

Dealer submitted hotline request to Ford to see what they would like them to do. Stated the foreman felt a small vibration so this is the action they are to take. Everyone at service department very nice to deal with, so we will see what Ford has to say.

My prediction: ford will say its within spec!

Dominant1 said:

My prediction: ford will say its within spec!

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Yep. That's what I am being told this week. Mine is on its second visit and the service advisor is telling me just that. First visit at 1200 miles they sent the DS out to be balanced. Problem solved temporarily. The vibration came back over the past 5000 miles. After 10 days they are now telling me that the constant popping noise from the rear while pulling away from a stop is in the diff, so that supposedly is being looked at now.

I am driving a 2017 Ecoboost/Auto as a loaner and this car drives as smooth as silk. As a rebuttal the service advisor is trying to convince me that the difference is due to the Eco/Auto....
:headbonk:

jc

johnscousin said:

Yep. That's what I am being told this week. Mine is on its second visit and the service advisor is telling me just that. First visit at 1200 miles they sent the DS out to be balanced. Problem solved temporarily. The vibration came back over the past 5000 miles. After 10 days they are now telling me that the constant popping noise from the rear while pulling away from a stop is in the diff, so that supposedly is being looked at now.

I am driving a 2017 Ecoboost/Auto as a loaner and this car drives as smooth as silk. As a rebuttal the service advisor is trying to convince me that the difference is due to the Eco/Auto....
:headbonk

jc

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Contact the Better Business Auto Line. I had this on my 2015. After being out of service for weeks, I contacted them. Ford corporate called and asked what I wanted to do. In the end, they replaced the entire rear and it went away. This,was the only way to get Ford to wake up.