Vibration between 50 & 70 mph

[Motoboy]

I agree, the dealer just rebuilt my differential and put in a driveshaft today. They are going to call tomorrow and tell me it still vibrates.....that's my guess. It just baffles me they won't just fix this problem.

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[offroadkarter]

I think we're making progress with this issue and I'm close to solving it for good.

God Speed, let us know how it comes out :cheers:

Hopefully a realigned sub frame and I assume a new wheel alignment won't require another driveshaft or anything stupid.

I would hope that Ford would take a very proactive approach and issue a TSB for all S550 cars built so far but that doesn;t seem to be happening.

It took Ford 10 years to issue a recall on the lighting control modules failing on 03+ panther platform cars. They recalled it 2 years after the car went out of production. This was an issue which would literally cause your headlights to either A. not turn on or B. turn off while driving. Kind of a major safety issue that Ford only got around to recalling after the NHTSA gave them shit from all the complains they were logging.


So yeah, we might get a recall out of this when the S650 is due for a facelift.

 

[Motoboy]

I agree, the dealer just rebuilt my differential and put in a driveshaft today. They are going to call tomorrow and tell me it still vibrates.....that's my guess. It just baffles me they won't just fix this problem.

Dealer just called, the driveshaft didn't fix it. They are waiting on Ford for the next step for resolution.

 

[shahram72]

I think they won't fix it because it requires braces or a different rear assembly and the tooling costs would be prohibitive. Even adding braces might change the collision characteristics, and that right there is why they won't fix it.

 

[Dannyho]

I've been having a suspicion that, in order to reduce NVH, Ford put super soft bushings at the engine mounts, transmission mounts, and rear subframe/ differential. And it's a combination of all that and the driveline alignment that makes it impossible to pin down.
Also, I'm positive the engineers know exactly what's wrong and some manager has poo-poo'd the fix for one reason or another.

 

[gov cheese]

After fixing mine myself... 2x and having it come back somewhat. I'm 99% sure its in the alignment of the rear end and cradle geometry being off. The DS balance is only part of the problem.
I'm going to align the cradle, diff bush inserts and shim the cradle as needed to get everything aligned true.
The first time it started vibrating was after the very first launch from a stop. Something shifted.... all makes sense now. It would come and go. I think we're making progress with this issue and I'm close to solving it for good.

Have close to 1000 miles on the car after the on car DS balance. 80-90% fixed, still feel the vibration but really have to be looking for it.
Think it was Speedfrk that mentioned Steeda sub frame braces help with his car. http://www.steeda.com/steeda-s550-mustang-rear-irs-subframe-brace-2015-coupe-555-5754/


Just installed Steeda sub frame braces definitely tightened up the rear-end. Hoping that they will help keep the IRS aligned. Everything lined up when installing the braces so my IRS should be pretty close to square.
Very easy to install on jack stands or ramps, took me less than two hours to install.
Tip there are two different length allen key headed bolts the shorter ones are used with the threaded plates.

 

[Sick03L]

Seems like it's safe to assume that movement of the cradle and diff is the culprit. I've simple jacked the car up rear diff and it got better when i drove it again then came back.
Order of repair should look like this:
Cradle alignment / lock out
Diff inserts
Possibly shim cradle to get correct rear to ds angle if off
Then balance the ds assembly on the car.

There is nothing more we can do then that. I guess a possible diff replacement if its damaged the gear set.

Thoughts?

 

[speedfrk]

Seems like it's safe to assume that movement of the cradle and diff is the culprit. I've simple jacked the car up rear diff and it got better when i drove it again then came back.
Order of repair should look like this:
Cradle alignment / lock out
Diff inserts
Possibly shim cradle to get correct rear to ds angle if off
Then balance the ds assembly on the car.

There is nothing more we can do then that. I guess a possible diff replacement if its damaged the gear set.

Thoughts?

Yeah, mine changes from day to day. It's mostly gone. Ford gave me a 100K extended warranty but I'm still worried about this car long term...
I'd also point out that measuring the run out on the pinion flange/DS attach is important. If it is out of round, it doesn't matter what you do, it will have a vibration.

 

[Sick03L]

Yeah, mine changes from day to day. It's mostly gone. Ford gave me a 100K extended warranty but I'm still worried about this car long term...
I'd also point out that measuring the run out on the pinion flange/DS attach is important. If it is out of round, it doesn't matter what you do, it will have a vibration.

I've had it gone 100%... don't think that's my issue.

 

[speedfrk]

I've had it gone 100%... don't think that's my issue.

Not talking about your car specifically, just the list of things that need to be checked on a car with the problem...

 

[ABS550]

Mine is still good.

I have 3+ months of smooth driving since my DS balance in my garage. No changes since then. About 2,500 miles, / 4,000 km of varied driving.;)
See post 1767 and 1773.
My runout was 0.020" on the DS.

 

[Mustg3]

Mines still vibrates after two driveshafts and differential replacement. The only repair left is having the D/S balanced on the car with hose clamps but can't find a dealer who will or knows how to perform this by following Fords instruction. At this point i am disgusted with Ford and am confident this is my last Ford purchase. This vibration defect we are all experiencing should embarrass any auto manufacturer who produces garbage like this.

 

[speedfrk]

Mines still vibrates after two driveshafts and differential replacement. The only repair left is having the D/S balanced on the car with hose clamps but can't find a dealer who will or knows how to perform this by following Fords instruction. At this point i am disgusted with Ford and am confident this is my last Ford purchase. This vibration defect we are all experiencing should embarrass any auto manufacturer who produces garbage like this.

You need to get Ford CS involved and tell them to have a FSE work on the car. Your dealer should have contacted the FSE in your area already.

 

[15Pony]

I've been having a suspicion that, in order to reduce NVH, Ford put super soft bushings at the engine mounts, transmission mounts, and rear subframe/ differential. And it's a combination of all that and the driveline alignment that makes it impossible to pin down.
Also, I'm positive the engineers know exactly what's wrong and some manager has poo-poo'd the fix for one reason or another.

I don't think its a design issue because ALL Mustangs would be built the same way and vibrate - but some including mine don't. I think its a manufacturing process issue where some parts are not being lined up properly when assembled.

 

[DarthMalice]

For those of you that have had bad issues with this, has anyone done the Steeda alignment kit and did it help? I don't have a bad vibration...slightly noticeable from about 55 to 60 then it tapers off. The Steeda kit seems like just a good thing to have though to prevent slipping (no clue why Ford wouldn't do something like that stock?!) so I am thinking about adding that and the steeda IRS brace.

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