Vibration between 50 & 70 mph

[347CobraII]

would be thrilled to know this is exactly what happens. as in, this is the official fix, and an updated part number, with an actual change in design.

can anyone get us some current part numbers and photos of the current driveshaft design, and possibly ones of the revised item when it arrives.


also anyone else that can corroborate this?

Don't get to wrapped up in part numbers just because they change don't mean different part

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[Cobra Jet]

would be thrilled to know this is exactly what happens. as in, this is the official fix, and an updated part number, with an actual change in design.

can anyone get us some current part numbers and photos of the current driveshaft design, and possibly ones of the revised item when it arrives.


also anyone else that can corroborate this?

Yes, I agree - you (scram99) NEED to tell your Dealership to take pics of your existing driveshaft assembly (whole unit) and the new one - side by side.

I have not heard a thing about this until now... I also wonder if those of us who have had the problem will get an offer to have our original (or replaced) units re-replaced with this new design (IF in fact true)...

Please keep us updated and try hard to get those pics!

 

[Jetboy]

I wonder if a slightly vibrating DS can ruin a rear diff? The new diff took most of the vib out of mine.

 

[scram99]

I wonder if a slightly vibrating DS can ruin a rear diff? The new diff took most of the vib out of mine.

That was my first question, should I even still be driving this? Service manager says (of course) that it will be fine, and it's all under warranty if a problem arrises.

 

[MikeD1]

Yes, I agree - you (scram99) NEED to tell your Dealership to take pics of your existing driveshaft assembly (whole unit) and the new one - side by side.

I have not heard a thing about this until now... I also wonder if those of us who have had the problem will get an offer to have our original (or replaced) units re-replaced with this new design (IF in fact true)...

Please keep us updated and try hard to get those pics!

Doubt they will replace them unless you go in again and the car is still having an issue with the vibration (like mine, where it's slowly creeping back in).

 

[Lo Pony]

I wonder if a slightly vibrating DS can ruin a rear diff? The new diff took most of the vib out of mine.

"Probably" not. Remember, solid axle cars have lots of vibration (i.e. all 1984-2014 Mustangs, exc. 99-03 IRS Cobra) that is never felt by the driver, since the axle is isolated from the frame. Those cars have no overt issues with the reliability of the pinion bearing (which would be the only thing that would be subject to wear). Our cars are just very susceptible to the problem, and it doesn't help that Ford's parts/tolerance matching is crappy.

 

[Lo Pony]

Doubt they will replace them unless you go in again and the car is still having an issue with the vibration (like mine, where it's slowly creeping back in).

Mike, that is interesting. As with several folks on here, mine didn't show up till over 3k miles on the odo.

Mike, how long has it been (mileage-wise) since yours was fixed? And did you notice the vibe when your car was new? AND, most importantly, do you know exactly what was replaced, or can you find out for us? (i.e. rear shaft + hangar bearing, rear shaft only, shaft + flange + seals, etc). If you can get the info, it might help us troubleshoot the reason why the vibration creeps back.

Seems to be, that the "creeping back" phenomenon could really only be due to one thing - a "soft" part that is wearing out or loosening.

 

[Lo Pony]

That is all the info the service manager had for me today, as soon as I learn more (part#, TSB, etc.) I will post ASAP.

Scram99 - Thanks for any info you can get. Optimally, can you coordinate with the dealership to be there when they get the parts and take pictures yourself?

There is some other information I'm curious about (See my earlier posts for lots of tech info). Scram, can you see if you can find out the following info from your dealer? It would be a very big help to lots of us here, and "being a big help to others" would be a good approach to use when talking to your dealer and asking for the info. Satisfy any desire they may have to be helpful.

1) What was the source of the information? (FSE, Cust. Svc, or what?)
2) The name of your FSE. Don't really need contact info (they would never give it out anyway), but it might be good as a referral "name drop" for other FSE's. Then they can look up the source of the information themselves.

I doubt there will be any visible differences between the old and new DS parts - I'm more curious where the information comes from.

 

[Lo Pony]

Scram99 - Thanks for any info you can get. Optimally, can you coordinate with the dealership to be there when they get the parts and take pictures yourself?

There is some other information I'm curious about. Scram, can you see if you can find out the following info from your dealer? It would be a very big help to lots of us here, and that would be a good context to use when you approach the dealer and ask for the info.

1) What was the source of the information? (FSE, Cust. Svc, or what?)
2) The name of your FSE. Don't really need contact info (they would never give it out anyway), but it might be good as a referral "name drop" for other FSE's. Then they can look up the source of the information themselves.

I doubt there will be any visible differences between the old and new DS parts - I'm more curious where the information comes from.

I wonder if any of this vibration can be attributed to the rubber "Giubos" - the isolator between the pinion flange and the rear differential mount. Or, if the differential mount bushings are softening/wearing prematurely and that is causing a change in driveline angle.

 

[GT Pony]

I wonder if any of this vibration can be attributed to the rubber "Giubos" - the isolator between the pinion flange and the rear differential mount. Or, if the differential mount bushings are softening/wearing prematurely and that is causing a change in driveline angle.

I would suspect the rubber bushing in the hanger located at the mid-point of the drive shaft assembly also. I think someone posted a video in this thread a while back showing the drive shaft vibrating at the mid-point bearing hanger while the car was up on a lift and being ran in gear.

 

[scram99]

I would suspect the rubber bushing in the hanger located at the mid-point of the drive shaft assembly also. I think someone posted a video in this thread a while back showing the drive shaft vibrating at the mid-point bearing hanger while the car was up on a lift and being ran in gear.

I also suspect this is the case, not sure why they went with a 2 piece drive shaft on a car with IRS and fixed diff anyway.

 

[scram99]

Scram99 - Thanks for any info you can get. Optimally, can you coordinate with the dealership to be there when they get the parts and take pictures yourself?

There is some other information I'm curious about (See my earlier posts for lots of tech info). Scram, can you see if you can find out the following info from your dealer? It would be a very big help to lots of us here, and "being a big help to others" would be a good approach to use when talking to your dealer and asking for the info. Satisfy any desire they may have to be helpful.

1) What was the source of the information? (FSE, Cust. Svc, or what?)
2) The name of your FSE. Don't really need contact info (they would never give it out anyway), but it might be good as a referral "name drop" for other FSE's. Then they can look up the source of the information themselves.

I doubt there will be any visible differences between the old and new DS parts - I'm more curious where the information comes from.

Source of the info , as I'm told from the service manager, is a Ford engineer, I can ask for his name. I won't have anyway of knowing when the part comes in until they call me and tell me it's there, however I am going to look at it when I take the car in to have it replaced, I'll grab some pics.

 

[MikeD1]

Mike, that is interesting. As with several folks on here, mine didn't show up till over 3k miles on the odo.

Mike, how long has it been (mileage-wise) since yours was fixed? And did you notice the vibe when your car was new? AND, most importantly, do you know exactly what was replaced, or can you find out for us? (i.e. rear shaft + hangar bearing, rear shaft only, shaft + flange + seals, etc). If you can get the info, it might help us troubleshoot the reason why the vibration creeps back.

Seems to be, that the "creeping back" phenomenon could really only be due to one thing - a "soft" part that is wearing out or loosening.

Mine did it from the very beginning. Car only has 1200 miles on it, been just a few months & 300 miles since the last fix.

Fix attempts have been:
roadforce bal all 4 tires
replace LR tire (would not RF bal)
replace the DS (2 times now, 1st replacement DS was worse than the OE one).
This round it's between 45-55mph, seems to mostly be in the steering wheel, no propeller noise - really feels more like wheel balance than anything else.

 

[speedfrk]

Mine did it from the very beginning. Car only has 1200 miles on it, been just a few months & 300 miles since the last fix.

Fix attempts have been:
roadforce bal all 4 tires
replace LR tire (would not RF bal)
replace the DS (2 times now, 1st replacement DS was worse than the OE one).

Yeah, mine also is coming back. It was smooth at all speeds and is still great above 70 but 60-65 is very noticeable again. Pretty discouraging. I'll drive it like this until there is confirmation that they have a redesigned part.

 

[Lo Pony]

Yeah, mine also is coming back. It was smooth at all speeds and is still great above 70 but 60-65 is very noticeable again. Pretty discouraging. I'll drive it like this until there is confirmation that they have a redesigned part.

Damn. Sorry speedfrk, that is very unfortunate! They field balanced your car too right?

There may be more to this problem in many cases then a mismatch at the flange and driveshaft, since when you balance the rotating assembly with washers or hose clamps, it should be a permanent fix! Now I'm starting to suspect some of the rubber or otheir soft parts that they put in the drivetrain, like the hanger bearing bushings, and the rubber isolator giubos at the flange. More of an argument to go with a one piece aluminum or carbon fiber driveshaft. But then again, you would probably have to end up field balancing that if you wanted a really smooth ride .

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