I was thinking about getting rid of the two piece driveshaft because I'm upgrading again so I'm probably going to be pushing around 500rwhp and 450rwtq. Is it going to be worth the $700+ or will that two piece driveshaft hold up for now?

 

The one-piece driveshaft is a mod you can feel. It is definitely worth it, even if you were not upgrading power.

 

Put one in and now I have a whine/noise. Until I find it, I'm not sure of straight shafts. Maybe that's why Ford put a break in the middle, for sound/noise problems. I also put on a new FR aluminum diff cover LCA/UCA relocation brackets, steel bradded clutch cable, lowered struts, springs, sway.

I hear it at 60 with steady pressure on the gas peddle. Lift off the peddle and the whine stutters and then stops around 50. Like a bad gear job only it's stock-nothing was touched inside the differential to change the cover. And $700 Ford Racing mufflers aren't supposed to drone.

Any Idea's - Bad, bent or out of alignment drive shaft?
Aluminum diff cover transfers more noise then ugly stock tin one?
Somethings out of alignment? I did gut the suspension.

Later

 

Wow dude i got the same anoying whining noise while cruising on highway, the noise get off when i remove pressure from gas pedal, i can hear it a bit in mid speed but it way more anoying on the highway, i have stock driveshaft but a 4.10 and lots of rear suspension work done to it too, wish i could figure out what causing this,even my loud muffler doesnt mute that lame noise

 

Going to put a Torson in leave 3.73 and with a rebuild kit and then I'll make sure 4 oz. of Ford Racing Friction Modifier bottle is added. Summer/Radio/Windows down I don't notice it so much but after 200 mi in the winter - you might be talking grounds for divorce here.

 

Had this same whine in my Ford Probe years back. Could hear it when you were feathering the throttle in 5th on highway. Back off the gas, went away. Got in it more, went away. They always contributed it to the way 5th gear was worn in the tranny and that's what was causing it. I can ever so faintly hear it in my '09 as well, but it only has 30k. All stock diff.

 

Also spherical end as opposed to Poly Bushings are louder because they are metal on metal so vibration and differential whine will be transmitted more. Best performance is louder. I'm workin it will let you'll know when I find the beast.

 

If I had an '09 with any sort of a build on it I would have a 1 piece driveshaft also.
I like the one Strang Eng. has out, if it's like the rest of the stuff they make it's a good part........