Vibration between 50 & 70 mph

[speedfrk]

I have been driving my car for two days to evaluate the on car DS balance the dealer just completed. I would say that 85-90 percent of the 50-70 mph vibration is gone. Have to really be looking for it to feel it. Hope this holds until Ford comes up with a better fix than putting a hose clamp on a new car.

SSM 45938 helped a lot when trying to convince a dealer that this is a real issue. For those going thru the "Ford" process of troubleshooting be patient.

BTW- There is one hose clamp on the DS. To completely remove the vibration a second hose clamp would have to be added. Not sure that last 10-15% is worth the extra time the car would have to spend at the dealers.

The FSE who did my car put washers under the bolt heads where the DS bolts to the pinion flange. The hose clamp is supposed to be just for diagnosing...

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[Blaster]

Yes, it occurs in the convertibles as well. Mine sat for a few weeks and when I next took it out and got up to around 50 mph it started vibrating so bad I thought the windshield was going to break from the dance it was doing.

I ended up swapping wheel/tires with a buddy that has an S550. Mine still vibrated and his with my tires and wheels was smooth as glass.

Long story short, I wasn't inclined to start the Merry Go Round with Ford over it. Mine had a tick in the engine, the a/c was warm on the drivers side the last two days I had the car and I didn't care much for the 6 speed auto, nor the sound of the coyote exhaust. I tried two different aftermarket cat back systems.

I got a good number in a trade for a new Chrysler Pacifica. I needed a new van and I have two other performance cars so the Mustang stayed with the Dodge dealer.

It saddens me, because I've owned a bunch of Mustangs over the years going back to a 69 Sportroof and I had very high hopes for the S550. I had bad experiences with Ford the last three Mustangs I bought. You know what they say about three strikes.

I'm done with them for now. I will not say for good, because one never knows what might come down the pipe to get me hooked again.

Man oh Man, did not want to hear that! I'm just about to put mine away for 6 months.

Well last new Ford was an 88 Ford pickup, straight 6 and Mazda 5 speed manual. Fabulous vehicle. I also bought a 3 year old 88 Town Car .... lets just say that quality was NOT Job 1. Last Ford until this Mustang which has just been great.

The shifting packing material inside the DS sounds intriguing.

 

[keltymd]

I love my dash cam. So it mounts right behind my rear view mirror so you dont see it unless you look through the windshield and it comes on with the ignition and has 128GB of HD recording with GPS and speed display on the recording. that being said. One of the techs took my car for a nice ride at about 100 miles per hour (the highest speed limit here is 70). I need to review the other recordings from it I guess too...................

Just watched one of the videos and they admit they hear the knock and can feel it in the shifter.

 

[shahram72]

Yes, it affects convertibles as well. First time I felt the vibration was in a convertible I rented before purchasing mine. I didn't think much of it at the time cause the first V6 I test drove before that was smooth as silk and this was just a rental so I could see if could get it up my driveway. So 2 out of 3 Mustangs I drove had it. See why I think they all do it to some degree? And why I am hesitant to upgrade to a GT? Only reason I want a GT is to have one, to feel like more "part of the club". I don't really want one. I'm happy with my power/payment/mpg. Let's see how long mine stays good. I wasn't going to post this yet, but it's already back. I can feel it at 55-60mph. It's slight, but it's there. I don't think this is fixable. Damn shame. There's not another car I want out there less than six figures. I figure right now I can still enjoy the car right now. Let's see where we are at next service interval. But I don't see owning this car out of warranty, and that's just sad and unacceptable.

 

[Sick03L]

Hate to admit it... my vibration has came back somewhat after the hose clamp fix. It was 95% better. I'd say it's 70% of what it was. VerifI'd it by running it up on jacks and it's definitely not as smooth as I had it :(
So now I'm lost... either the diff is moving / sagging causing the pinion angle to change or something is wearing out.
My vibration was always worse on decel.. when the rear was unloaded. I'm really thinking drive shaft and pinion angle are at play here causings part of this or all of it.

 

[Cobra Jet]

I just took mine in today for this reason. I am having to play the trial and error diagnostics right now. They are going to swap my aftermarket wheels with some off of a new car just to eliminate that possibility. I have no problem with that though. I did take the service manager for a ride and pointed it out to him between 70-80. I let him drive it back to the dealership and he noticed it really bad around 60. He even thinks its the drive shaft. He made the comment that the drive shafts have card board inside them for noise reduction and that it sometimes comes loose and can cause issues. He said they send the DS to have the ends cut off and the card board removed, reattached, balanced and the problem goes away. I am not sure if this is the issue I am having but it is def. noticeable and it is not the wheels and tires because it was doing it before but I figured it was the wheel spacers and said oh well.

I'll post what the determination is.

I have never heard of a drive shaft containing packing material INSIDE of the tubing!

I would like to see an S550 DS dissected and posted on here... It would be interesting if that is true...

 

[GT Pony]

The cardboard inside the hollow drive shaft sounds a bit out there - like to hear if someone has actually cut open a driveshaft to verify this. Maybe it was the same guys who kept putting empty beer cans inside the door panels that caused rattles.

 

[Sick03L]

Ok.. shit is getting weird, seriously. So I indexted the DS without moving the clamp and it got 5x worse lol. Took off the clamp and just as bad. Put the clamp back but moved it to the larger welded on weight..... BOOM. Smooth as glass again.
This is really mind boggling. How can the DS go out of balance once I had it balanced? Then be ok by moving the weight / clamp. Unless it's true about an inside piece of cardboard that comes loose.
Not really cool with self balancing the DS every 1000 miles or so... smh.

 

[Cobra Jet]

Ok.. shit is getting weird, seriously. So I indexted the DS without moving the clamp and it got 5x worse lol. Took off the clamp and just as bad. Put the clamp back but moved it to the larger welded on weight..... BOOM. Smooth as glass again.
This is really mind boggling. How can the DS go out of balance once I had it balanced? Then be ok by moving the weight / clamp. Unless it's true about an inside piece of cardboard that comes loose.
Not really cool with self balancing the DS every 1000 miles or so... smh.

Any pics to show how you have the clamp currently positioned?

 

[speedfrk]

Ok.. shit is getting weird, seriously. So I indexted the DS without moving the clamp and it got 5x worse lol. Took off the clamp and just as bad. Put the clamp back but moved it to the larger welded on weight..... BOOM. Smooth as glass again.
This is really mind boggling. How can the DS go out of balance once I had it balanced? Then be ok by moving the weight / clamp. Unless it's true about an inside piece of cardboard that comes loose.
Not really cool with self balancing the DS every 1000 miles or so... smh.

If you indexed the DS, you unbalanced the assembly. The weight balances the DS, pinion flange and even the pinion shaft- not just the DS.

If the assembly went out of balance after you had it smooth, the clamp probably moved slightly. Mark the position of the screw part of the clamp with some paint so you can see if it moves.

Driveline angles do make a difference and everything in the rear subframe is rubber mounted. The Steeda subframe braces helped my car especially with the power off increase in vibration.

 

[15Pony]

While this is not a Mustang drive shaft, its a Ford - probably an F150 and FordTech cuts it open. Cardboard. See it here:

 

[BlackGT]

new driveshaft on order for mine... we will see if this works.

 

[keltymd]

I got tired of the dealer not doing anything so I took matters into my own hand. Whenever I install K Member I always square it up. measure from the rear mount bolt to the rear of the car at the mount for the axle or IRS on the opposite side. Well I cross measured my IRS cradle off of the KMember and squared it up then installed the Steeda IRS subframe support brace and guess what. I am not vibrating at any speed now. My IRS Cradle was way out of wack (about 1/2-3/4") and when I centered it the vibration went away. I was going to use the alignment dowels Steeda sells but thought putting those in would make for a more solid rear and would amplify any vibration.

 

[blucifer]

drive shaft, replaced same issue. Half shafts replaced, same issue. IRS is currently being rebuilt now.

 

[BlackGT]

Well, not sure how long it will take to get the driveshaft ordered... Ford, in there infinite wisdom has one central hub that handles all of their computer needs apparently and it has caught on fire.

We shall see.

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