Driveline whine/whistle

[Kenneth Olsen]

1973 3.0cs with Getrag 265 OD high-pitched whine/whistle at 40 to 60 mph in 3rd, 4th and 5th under load. Noise disappears off throttle. Think of flute or wet wine glass rim. Increases in intensity with road speed. No vibration felt through shifter, all shifting smooth, no synchro issues. Transmission output shaft bearing? Center support bearing? I value your thoughts.

 

[Mike Goble]

I have the same whine - it's faint and only under load. I think it's gear whine from the differential.

 

[Kenneth Olsen]

I have the same whine - it's faint and only under load. I think it's gear whine from the differential.

Thank you...yes that is a candidate...I'm scheduling a trip on a dyno to do some close listening.

 

[Thomas76]

Center support typically causes driveshaft wobble/vib you can feel in the seat, at least when the rubber is worn. I would think that wobble would be there all the time, not just under load.
Hopefully it's improper spacing on your diff ring and pinion, that feels like the least expensive option.
Transmission bearings are more complicated.