Vibration between 50 & 70 mph

[Dave]

Yeah I voted "no" but having subsequently spent several more hours in the car, I believe mine has this issue, 1100 miles but it's been doing it since it was new.

I noticed it on the test drive. Salesman says it has "been sitting" so I figure it's got a flat-spotted tire. I aired the tires up to 38 psi and drove a few hundred miles on an 85 degree day, it's not the tires.

About 50 - 55 mph the vibration starts coming on, and it tapers off by about 75, car is smooth as glass at 80.

Aside from that, the driver's side window catches on the trim when you open the door (intermittently, but it's getting worse with the cold weather) and there is some light rattle (throwout bearing?) from the clutch when you engage at a low RPM (like with the hill start assist.)

I am taking the car in Wednesday for all of this stuff. Hopefully they can fix the vibration, it's like a roaring sound almost, and even on the smoothest pavement I can find around here, it never goes away until 80 mph.

Love this car but these issues are a real buzz kill. Ford could stand to up their game on the QC end of things.

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[dbranger94]

I'm not reading 130 pages, but I too have a slight vibration at exactly 70mph sometimes. When it starts vibrating, I let off the accelerator for a few seconds and coast, then get back into the throttle. The vibration will go from say a 4/10 to a 2/10. If I stop altogether, the vibration goes away completely when I resume.

Here is some good info on drive shafts in general...

 

[keltymd]

Im starting to wonder why nobody has made a bushing like they did for the rear tranny mount for the driveshaft mount. I wonder if its soft rubber is contributing to a lot of this vibration issue

 

[theredmeadow]

Im starting to wonder why nobody has made a bushing like they did for the rear tranny mount for the driveshaft mount. I wonder if its soft rubber is contributing to a lot of this vibration issue

a shop foreman had wondered the same thing. if it could be resolved with a different/better mount.

 

[BMR Tech]

Im starting to wonder why nobody has made a bushing like they did for the rear tranny mount for the driveshaft mount. I wonder if its soft rubber is contributing to a lot of this vibration issue

I am working on figuring this out.

What I have found, since playing and ripping into these cars since Aug,2014....is that the driveline angles are HORRIBLE on these S550 Mustangs. Absolutely, positively horrible. I wonder all the time, why this was done. It makes zero sense to me.

Ford went from the S197 which had decent angles, to this S550 which is mind blowing.

To put it into perspective, the S197 Mustangs had engine/trans angles that went down on average about 2.5 degrees, and the pinion flanges were usually around 0 degrees. Under load, when the pinion would rise, it would place the working angles in parallel with approximately 1 degree of working angle on each end.

This S550............lol.... I am seeing angles all over the place.

My new stock PP GT....the pinion flange angle is actually over 2 degrees HIGHER / pointing up - than the trans angle. I am surprised any DS at all can handle this, regardless of the design. That pinion rises even more than that under load....so the pinion is pointing up likely 3+ degrees higher than the trans.

I have attached some pics of some angles I took on our PP in house that we have all of our solid bushings on....which made the angles better, but they are still horrible.

This shows the engine/trans angle going down 3.5 degrees...and the pinion flange angle going up 4.1 degrees. lol

 

[speedfrk]

I am working on figuring this out.

What I have found, since playing and ripping into these cars since Aug,2014....is that the driveline angles are HORRIBLE on these S550 Mustangs. Absolutely, positively horrible. I wonder all the time, why this was done. It makes zero sense to me.

Ford went from the S197 which had decent angles, to this S550 which is mind blowing.

To put it into perspective, the S197 Mustangs had engine/trans angles that went down on average about 2.5 degrees, and the pinion flanges were usually around 0 degrees. Under load, when the pinion would rise, it would place the working angles in parallel with approximately 1 degree of working angle on each end.

This S550............lol.... I am seeing angles all over the place.

My new stock PP GT....the pinion flange angle is actually over 2 degrees HIGHER / pointing up - than the trans angle. I am surprised any DS at all can handle this, regardless of the design. That pinion rises even more than that under load....so the pinion is pointing up likely 3+ degrees higher than the trans.

I have attached some pics of some angles I took on our PP in house that we have all of our solid bushings on....which made the angles better, but they are still horrible.

This shows the engine/trans angle going down 3.5 degrees...and the pinion flange angle going up 4.1 degrees. lol

This is maybe why there is always some DL vibration in these cars even after balancing, etc. The Ford FSE told me that they all have it to some degree but most people just don't notice it.

 

[theredmeadow]

This is maybe why there is always some DL vibration in these cars even after balancing, etc. The Ford FSE told me that they all have it to some degree but most people just don't notice it.

oh man, yeah mine was a light drone at 55-70 thats why i never took it in but i ended up taking it in friday and haven't heard from them yet. the foreman wasn't convinced there was any noise or vibration.

 

[BMR Tech]

I am working on a driveline angle fix kit....

I would love to find someone with this issue on a BONE STOCK car....where the issue is reallly noticeable/bad.

Any Tampa Local cars have this issue?

 

[pullingeez]

Kelly iim in Orlando and other than twins its stock. Jeff Rogers.

 

[BMR Tech]

Kelly iim in Orlando and other than twins its stock. Jeff Rogers.

Stock DS? I need to test with stock DS

 

[pullingeez]

I have both

 

[pullingeez]

I'll pm u on FB my contact info

 

[speedfrk]

The DL angle thing is probably why my car also had a difference in power on/off vibration/drone even just on the interstate. The subframe braces made a big difference in that...

 

[Seewolf]

When this would be the solution.....oh boy....Mustang owners will love you.

 

[dbranger94]

I was about to go out and stick an angle gauge on mine, but BMR beat me to it. Those angles are ridiculous if they are consistent with all models. Probably varies between engines/transmissions though. A one-piece shaft wouldn't even help in most cases. And shimming the rear sub-frame would probably cause other issues. BMR could fill us in better on this than I could. Perhaps eccentric bolts on the diff itself? Don't know if there's enough wiggle room for that?

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