whining noise when decelerating in 1,2,3 and R

[kepm123]

So my truck has a whining noise when slowing down in gear with clutch fully engaged (pedal released) I can hear it in 1,2,3 and R. The car has to be warmed up for a little (5-10 miles) at a decent speed.

Here are the 2 videos, can barely hear it over road noise. might need to turn it up, or use head phones.

http://www.flickr.com/photos/ken_mott/3550711322

http://www.flickr.com/photos/ken_mott/3550710316

Can't tell if its transmission, driveshart, mounts.

The transmission goes into gear fine. I don't have any grinding.

Ideas?

 

[AllanD]

The mazda trans tends to be a bit noisy because the thin oil it
uses doesn't damp that noise.

And in "4th gear" no actual gears are involved in transmitting power

the input shaft is coupled to the output shaft... so the trans will
usually be quietest in 4th.

Any noises you hear in 4th can generally be presumed to NOT be caused by the transmission

 

[kepm123]

This is a new noise. I has never done it before til recently.

I do not have any noises in 4th.

 

[AllanD]

it COULD be a symptom of a "pocket" bearing on it's way out

the little bearing that "pilots" the mainshaft
of the trans inside the pocket in the back of the input gear
is NOT loaded in 4th gear.

If it is the pocket the character of the noise should change in 5th and reverse compared to 1st, 2nd & 3rd because in the first three gears the two shafts are rotating together
with the greatest relative speed in 1st and diminishing in 2nd & 3rd.

There is ZERO relative motion in 4th and the two shafts are actually counter-rotating
in 5th & Reverse. though in reverse the speed is similar to the speed in 1st
in 5th the speed is rather slow... about 1/2 the relative speed you'd see in 3rd.

Isn't all this "spacial relationship" thinking fun?

AD

 

[kepm123]

So i was told its the drive by the shop i go to. He said the piece inside broke.