Why did Ford decide to do this? It's obviously more work and money for them to engineer a two-piece shaft, and it's clearly heavier than any one-piece. So why did they do it? Did they find vibration issues with one-piece shafts?
Why a two-piece driveshaft?
- Thread starter Bingo
- Start date
They noted "cabin noise" in the press release...
I can also tell you from experience that if you have the stock motor mounts - the addition of a 1pc DS causes/allows significantly more movent of the transmission/engine and thus screws up the alignment of the shifter even more than normal. The driveshaft acts like a gyroscope trying to resist movement other than rotation. With the 2pc - the part connected to the transmission NEVER moves because of the rear going up and down. So, they isolate the trans/engine from this force...
My guess is that it was a combo of the 2 - but given all the dampeners they put on the GT and GT500 driveshaft, transmission and pinion flange - "vibration" pretty much sums up a clear concern that this is trying to address...
That leads me to my next question...
I experience a lot of 'clunking' at low speeds/low gear (i.e. the car doesn't roll smoothly). Is that a driveshaft thing...or an engine/tune issue?
I've heard people say the addition of a one-piece shaft makes the car feel smoother...
I experience a lot of 'clunking' at low speeds/low gear (i.e. the car doesn't roll smoothly). Is that a driveshaft thing...or an engine/tune issue?
I've heard people say the addition of a one-piece shaft makes the car feel smoother...
rog06gt
Mash it!!!
Believe me if they could have avoided the 2 piece DS they would have, it is very costly for a manufacturer when compared to a 1 piece...
Don't forget that this driveshaft has 2 axes to deal with, the normal up & down movement (suspension extension/compression) and also a side to side movement from the panhard bar set up...that creates a compounded angle on the pinion...
I also had a very interesting conversation with the owner of the Driveshaftshop, there is also harmonic vibrations created by the crankshaft torsional movement and that also gets transmitted trough the driveline...
Here is an interseting read for the curious ones...
Cheers
Don't forget that this driveshaft has 2 axes to deal with, the normal up & down movement (suspension extension/compression) and also a side to side movement from the panhard bar set up...that creates a compounded angle on the pinion...
I also had a very interesting conversation with the owner of the Driveshaftshop, there is also harmonic vibrations created by the crankshaft torsional movement and that also gets transmitted trough the driveline...
Here is an interseting read for the curious ones...
Cheers
Driveshaft definitely contributes to this and yes it gets noticeably better with a 1pc...
rog06gt's comments match various things I have heard and observed - I have seen at least one comment (from someone talking to ford) that the speed limiter is set by ford not because they are trying to be your mother, but rather due to "safety concerns relating to driveshaft harmonics".
If you look carefully at the stock shaft you will notice features that confirm all of this...
The back half is narrower, we can presume to reduce weight as this is the part that is subject to all the movement (side-to-side, up-and-down). Gyroscopic forces generated by the shaft spinning will fight this movement with a force corresponding to its rotational speed. Again the whole point here is to isolate the engine/trans from the rear's movement. This limits this gyroscopic action to the rear shaft and by making that part small - it holds those forces down to a dull roar...
I agree that "Ford would not do this if they did not have to" - though I am not sure it is clear to us what the entire universe of "constraints" were that made them "have to do this"? Cost of component manufacture, assembly and repair can do some strange things to the final analysis of what makes sense for Ford to build vs what we want to work on...
travelers
Senior Member
Hey if you want to catch up with me some time this week I'll take you for a ride and let you feel it for your self.
Buzzystang
forum member
So...if Ford went to all this trouble to reduce NVH w/ a 2 piece driveshaft, then one should assume a 1 piece would increase NVH. But most comments I have read , especially about Spyder's, don't mention any increase in NVH at all.
silverbull1tt
forum member
- Joined
- May 26, 2007
- Posts
- 90
- Reaction score
- 0
Have there been any OEM driveshaft failures? I would like to replace mine down the line, but since I don't do any type of racing it's not really a priority of mine.
Good information...thank you, all.
Sounds good...let me know when and where. I'd also like to hear your exhaust setup...
Sounds good...let me know when and where. I'd also like to hear your exhaust setup...
They have been destroyed by high HP setups... I have read of 2 instances of failure in stock form which appeared to have been seized pinions from the factory - but no they are not "prone to failure" from what I have seen (JMO)
We replace them around here:
a. to get rid of the "slap" between gears
b. weight period and rotational weight
c. lotsa torque
d. aluminum is pretty
It'll reduce it, but not eliminate it...and since the Spyder is lighter, and requires less to move it, if you drive like a dork with sharp throttle imputs (on or off), it will still "slap". But like I posted in a separate thread, slap is life in the fast lane: my '99 C5 Vette did it, and it had the DS inside a torque tube..my '97 Viper GTS did it, and (sigh) my S197 does it too...smooth throttle input will all but eliminate it...but b, c, and d are all valid reasons.
Similar threads
Support us!
Support Us - Become A Supporting Member Today!
Click Here For Details
Sponsor Links
