I've searched high and low for a thread on this issue with no success.

In the mornings when I start the car to go to work, I shift the car into drive, and I hear a momentary rattle from the transmission as it shifts into gear. The shifting itself happens just fine, but as it does it, it makes a sound as if something is loose. The best way to describe the sound would be a marble or bunch of marbles in a corner somewhere that shake or bounce whenever the transmission changes gears. I also hear the sound when I'm slowing to a halt and the engine shifts to first gear (manual mode). The noise doesn't happen when the engine warms up.

If for example I have the day off and don't start the car until it's hot outside, I don't hear the noise. It definitely seems to be temperature-related.

Any ideas?

 

Have you tried changing your fluid?

 

Fluid was changed about a month or two ago.