Noise: Auto Trans - bushing help?

Transmission pros - please help?

Background - TH350 has a noise/vibration at one specific cruising throttle position. Sounds like a loose bearing being hammered.  Goes away with less or more throttle.  Slowly becoming more and more noticeable (louder, and wider throttle position). I can feel it in the floor; I can hear it, it's getting worse and I hate it.

Can duplicate the noise on the lift, around 2500-3000rpm in drive, and it sounds strongly like it's coming from the back of the trans, like the rear case bushing.  It's not the extension housing bushing for sure. Output shaft had more side-to-side movement than I expected, but without the driveshaft and extension housing and bushing - normal??

Much more noticeable in Direct than in 2nd for sure. It seemed very road-speed-related, but now I'm second-guessing myself. I didn't notice it at 2500-3000 in 1st or 2nd.

Dropped the trans to inspect, some brass in the pan, but nowhere near what I'm expecting. Direct Drum bushing looks very nice (but I'm going to replace it with a "wide" bushing anyway). Wee bushing in the output shaft looks nice. Input shaft bushings in the front bump look nice. Theoretically the only bushings in use in Direct are the front pump, input shaft at pump, Direct Drum, and rear case?

Old case bushing (top), new case bushing (bottom).  Cannot "feel" any irregularities by finger.  Both measure the same ID. No evidence of bushing "spinning" in case.

(click to biggie-size):

Other side, old on top, new on bottom (click to biggie-size):

Front Pump Bushing (click to biggie-size):

(click to biggie-size):

They look nasty in the pics, but they don't feel that nasty, and they mic the same as the new ones.

What gives?

if it's only at certain RPM in all gears, then I'd be looking at the input side, not the output.  output speed changes with speed of vehicle, input side changes according to engine speed.

It's MUCH more noticeable (in both sound and vibration) in 3rd.  I -think- I can feel it sort of in 2nd, and I have never gotten it to do it in 1st, all at the same engine rpm.

Could it be that 3rd is a higher load on the input shaft?

In reply to SkinnyG :

You say it’s more noticeable in third gear. How old is your torque converter? Could it be out of whack?

Torque converter is 3 years old.  Have noticed nothing different in its performance.   It's a non-lockup 2500 stall from Hughes.

But converter issues should go away in neutral or park, and be noticeable in gear and certainly so if the car is not moving. No noises from the torque converter at all.

if it's more noticeable in 3rd, look at the direct drive drum then.  Yes it's probably internal IMO

The Direct drum bushing looks beautiful. But I have a "wide" bushing to put in, so I'll do that anyway.

Wait a tick.

Literally.

The rear most Torrington bearing makes a clicking noise.

I flushed the snot out of it with brake clean and compressed air a number of times, and it's smooth now, but I'm not convinced there isn't damage.  I have another TH350 that I'll strip and take the Torrington out of there and mic it for comparison, but I'll use that one regardless.

That could be the noise.

 Did You Check The Drive Shaft ?

Driveshaft u-joints are solid, and both joints new two years ago.  Zero play.

Sometimes i find it helpful to think about vibrations in terms of the sheer energy required to create it and whether the tiny part you are looking at could actually do that for the duration that you've experienced it without being destroyed.