Drivetrain Let's plate guess that noise.

[Mustang5L5]

Tried to get a sound clip, but no luck. But anyway let's play a game. I've had this noise for s few weeks and can't ID it.

Here's the facts.

1. Sounds like a high pitched noise. Similar to what a centrifugal blower at idle sounds like, but quieter
2. Does not increase speed with rpm or vehicle speed -remains constant
3. Not present when idling or inching the car back and forth a few feet
4. Only starts at approx 3-4 mph and higher
5. Stops when I slow down and reach 3-4 mph
6. Volumn is constant. Speed above 10-15mph drowns it out
7. Comin from trans tunnel area in any zone from bellhousing to mid driveshaft. Unable to pinpoint
8. Seems to disappear when it's hot out > 85 degrees
9. Not related to clutch position or gear.

Ok, give me some ideas. I haven't had a chance to put the rear axle up on jackstands and put the car in 2nd and let it idle in gear yet.

 

[JD1964]

squeaky speedometer cable or speed sensor on trans tail?

 

[DSB88GT]

Sounds similar to my squeaky speedo cable. Volume is inversely proportional with outside temp!

 

[Mustang5L5]

Does the sound change based on vehicle speed?

 

[DSB88GT]

Does the sound change based on vehicle speed?

ehh...i guess the sound does kinda change with speed. but not really that much.

 

[jrichker]

Wind noise - I chased such a noise for quite some time before I figures out that it was wind blowing around the trim or something like that.

 

[Mustang5L5]

Not at that low speed. Same sound if I back out of the driveway. It literally starts at maybe 1-2mph

 

[JD1964]

Unhook speedometer cable at trans and test drive. See if that makes the noise stop

 

[Mustang5L5]

UPDATE.

It was the rear tailshaft bushing seal. A little spray lubricant and it went away.

 

[Blown88GT]

Is that where the driveshaft yoke slides in?
Pull the driveshaft & grease it up. Spray lube won't last. Spray white lithium great might.

I just replaced the driveshaft with the FRP aluminum & then rebuilt the old one better than new. Had trouble finding u-joints that were a good fit.
https://www.stangnet.com/mustang-forums/threads/drive-shaft-with-new-u-joints.908924/

 

[Mustang5L5]

It's already an AL piece.

Entire drivetrain is coming out this fall anyway. Spray lube will do fine for the 100 or so miles I'll drive until then. I'll grease it when I put it back