Noise coming from transmission/TC area (1 Viewer)

[Supra88]

Need some help here. A couple of months ago I developed a strange rattling/whirling sound coming from what I thought was the engine bay. I pulled the serpentine belt off and checked all of the pulleys. The idler pulley seemed loose and made a very slight noise when I spun it. Everything else seemed fine. The power steering pulley/shaft did have some back and forth play on the shaft, but I think it was normal. I swapped out the idler pulley and belt with new OEM ones. The problem is still there.

Here's where I'm at right now:

The sound only happens when the engine/drive train is cold
The sound appears to be loudest under the transmission pan

I know it's not the typical TC cold weather whirl, I'm familiar with that.
It's not the header as I have DT headers.
I did a mobil 1 ATF drain/refill last week (after the problem started)

Any suggestions? I'm at a loss.

 

[Supra88]

Another note- everything is completely quiet once everything is mostly warmed up. I just changed the TC gear oil for good measure.

 

[Supra88]

Okay - I figured out the problem. I narrowed the noise down to the transmission/bell housing area. I pulled the transmission pan and inspected the filter. Almost 100% plugged with caked on muck. For the record I’ve been running Mobil 1 ATF for the last 110,000 miles with multiple drain and refills and even did a complete fluid exchange a few years ago. The pump was starving for fluid, particularly when viscous while cold. Anyway, I changed the filter and everything is smooth and quiet. Check you filters! I always figured it was a coarse screen and never dropped the pan. Highly recommend doing so. I was at 230,000 miles.

 

[deltapine1]

I have a similar noise, it seems to go away when shifted into Neutral. If I put it in Drive and hold the brake pedal down it gets louder. The fluid was changed with Amsoil product about 20k miles ago.