Transmission intermittent whirr sound

[pressonregardless]

Went for a two hour drive to explore this weekend. Turned down an "old vintage road" no painted lines, one lane bridges, extremely bumpy, seldom used and dropped my speed due to the rough conditions, mostly 2nd gear and bottom of third gear speeds (30 mph). So bouncing around violently at times, after about 10 minutes, I hear what sounds like a "loose gear that tipped or fell rubbing against the output of the transmission. This noise is speed dependent, not affected by engine RPM, nor any gear, nor clutch in or out.

I pulled over and depressed the clutch then selected 1st, 2nd, 3rd, 4th, 5th gear. Then went for reverse and herd a sound like the car is slow rolling and you try to go into reverse. I was stationary. I depressed the clutch again and waited about 10 seconds, selected reverse again and it went into gear and backs up the car.

So, I continue on this very bumpy road and 1/4 mile of complete quiet and hit a bump and Whirrrrr again. Limped home by stopping the car and selecting Reverse when ever the sound appeared. Going to drop the GL-1 and inspect or metal.

I have searched both "Fiatspider.com" and "Mirafiori.com" and nothing like this shows up. Suggestions? ?

[baltobernie]

... This noise is speed dependent, not affected by engine RPM, nor any gear, nor clutch in or out...

This is a good clue that the problem is drive line related. I would start by looking at the rubber items (guibo, center support). If these aren't flopping around, next would be U-joints and wheel bearings. But I bet the culprit is the rubber bits.

[pressonregardless]

Today put the Spider up on jack stands and began an inspection. Found some PO added extra "rubber matting" for sound-heat control and over the years, it slowly slipped down and was "grabbed" by the flex disc (Guibio). It looked like it was formed out of a floor mat, cut to fit under the foam rubber boot.
Since I have it "in the air" I dropped the Transmission pan to clean it. Found some tiny brass specks, no steel. Physical inspection of the transmission internals all look normal. So tomorrow, button up, add 1.75 Qt of GL-1.

Fingers crossed!