Vibration between 50 & 70 mph

barrykaye1001 said:

Was just looking at the poll results for this thread. Out of 947 voters, more than half haven't experienced the dreaded vibration. My question: where did the rest of us go wrong??!! :frusty:

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I had voted no vibration on this pole ...But at that time I only had 1500 miles on the car .. My Vibration started at 2500 to 3000 miles of use ..:frusty:

smokinzx14r said:

I had voted no vibration on this pole ...But at that time I only had 1500 miles on the car .. My Vibration started at 2500 to 3000 miles of use ..:frusty:

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I did the same thing.....my vibration started at about 3,500 and I sold the car with 5,000.

I got my car with 4000 miles on it and always thought it ran a little rougher between 50 to 70 miles an hour then my EcoBoost did. Then it progressively got to the point where I knew it wasn't just the characteristics of the car and Ford had mine all summer and never fixed it after replacing part after part after part. Traded it in couple months ago. I love the look of the Mustang but this has scared away from them

hlh1 said:

Just received the low quality roll of the dice... Maybe ours were made on Monday or Friday...

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I’m still interested to hear what the exact issue is on them. I’m at 30k+ miles and have no vibrations even past 100+. I need to check out a local one that is vibrating because I want to see how it feels, etc.

Since no one actually knows what the “main cause” is and Ford doesn’t do anything to really solve the issue people will be hung out to dry. I don’t think it is as widespread as people make it out to be but if you have it it’s bad. The AC issue also makes no sense. Some people have multiple failures while some have not had a single one. Is there another defective part that is causing something else to fail?

thehunterooo said:

Since no one actually knows what the “main cause” is

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Sure looks to me like the main cause is that the pinion yoke (which is bulky/heavy) and drive shaft are not balanced as an assembly.

The DS has some balance tolerance set by the factory, with the heavy side marked with a yellow paint splot. To counter this manufacturing tolerance, the yoke is pre-drilled to reduce weight in one spot. When the DS and yoke are finally assembled, they line up the heavy spot of the DS with the light part of the yoke the best they can and hope for the best. The amount of imbalance we're talking about here is grams or fraction of a gram. Unfortunately the chassis of the S550 is like an antenna for driveline vibration, with the focused receiver being the driver area.

lugz said:

Sure looks to me like the main cause is that the pinion yoke (which is bulky/heavy) and drive shaft are not balanced as an assembly.

The DS has some balance tolerance set by the factory, with the heavy side marked with a yellow paint splot. To counter this manufacturing tolerance, the yoke is pre-drilled to reduce weight in one spot. When the DS and yoke are finally assembled, they line up the heavy spot of the DS with the light part of the yoke the best they can and hope for the best. The amount of imbalance we're talking about here is grams or fraction of a gram. Unfortunately the chassis of the S550 is like an antenna for driveline vibration, with the focused receiver being the driver area.

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I suppose that's why balancing with hose clamps while on the car works - it balances the whole thing.

lugz said:

Sure looks to me like the main cause is that the pinion yoke (which is bulky/heavy) and drive shaft are not balanced as an assembly.

The DS has some balance tolerance set by the factory, with the heavy side marked with a yellow paint splot. To counter this manufacturing tolerance, the yoke is pre-drilled to reduce weight in one spot. When the DS and yoke are finally assembled, they line up the heavy spot of the DS with the light part of the yoke the best they can and hope for the best. The amount of imbalance we're talking about here is grams or fraction of a gram. Unfortunately the chassis of the S550 is like an antenna for driveline vibration, with the focused receiver being the driver area.

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But then how do explain the fact i knocked out like 95% of my aftermarket ds vibration by adding 1/4” shims to my x member! I have this part to take care of the rest, and i know it will work when i get it on!

http://www.balancemasters.com/driveshafts.html

Dominant1 said:

But then how do explain the fact i knocked out like 95% of my aftermarket ds vibration by adding 1/4” shims to my x member!

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Well, a 1-pc DS is a different question from the factory vibration problem. I agree that with a 1-pc the driveline angles are not conducive for smooth operation. I also shimmed my transmission xmember to help the angles, but ultimately I had to tweak the balance at the yoke to get it perfect.

Update: New diff installed. Still vibrates. Not as much maybe. The vibration harness says that the detected variance has been eliminated. I asked them to put it on a lift and bring it up to speed. They did and we could not see any vibration in the drive shaft anywhere. The mechanic said the diff had a different yoke than my old one. Came off the 2018 assembly line.

One of the staff has a 17 GT CS Convertible and I asked if I could take it for a spin. She agreed and I drove it about twenty miles. Guess what? It vibrated as much if not more than mine.

Now what? Maybe my expectations are not realistic. I am going to switch to a different brand tire when the opportunity presents and see if that helps.

Dominant1 said:

But then how do explain the fact i knocked out like 95% of my aftermarket ds vibration by adding 1/4” shims to my x member! I have this part to take care of the rest, and i know it will work when i get it on!

http://www.balancemasters.com/driveshafts.html

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Finding this prob is like playing whack-a-mole :headbonk:

Seems like for some the prob is geometry, for others it's balance and for others it's both. You may fall in to the third category.

The Ford dealer is going to try balancing my DS on the car. I am going to be there when he does it to make sure it's correct.

I have a Balance Master Balancer for a V-6 for sale. PM me if your interested.

Mustg3 said:

I have a Balance Master Balancer for a V-6 for sale. PM me if your interested.

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Can we assume it didn't work?

Dominant1 said:

no not yet maybe the weekend if i have time...

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Have you installed it yet? Did it help?

To install this on the stock driveshaft one end need to be disassembled, about a 3 hour labor charge with no guarantee it will work. So I never installed it.

Mustg3 said:

To install this on the stock driveshaft one end need to be disassembled, about a 3 hour labor charge with no guarantee it will work. So I never installed it.

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Take one for the team!