Tc Noise?

[satyr]

Hi, I could use some advice regarding my 89 Suburban with rebuilt 700r4. I've noticed when cold, acceleration in first and second gear is OK- but as it warms up it appears to be slipping- especially in 3rd gear. I've also noticed vibration in 3rd when getting on the freeway as well. (haven't checked the carrier bearing yet- but that is only 5 years old). Recently- I discovered a new noise- sounds like its coming from the bellhousing....

 

Today (in park) when I was under the hood and manually revved it to around 2000-2200 rpm, as the motor returned to idle- there was a weird metal on metal "groan" sound from the rear of the motor. It made the sound (like a creaking metal door hinge) for around 2 seconds. I repeated the rev and got the same weird noise each time. I checked tranny fluid- and its full and clean. I took it out for a test drive and it ran OK- but when I got back to the house- the sound became more prominent as I drove up the driveway- (there was a small amount of wheel spin due to the snow). I popped the hood and was able to produce the noise by revving it slightly- but it wasn't as loud as it was under a load going up the driveway. I'm wondering if this might be due to torque converter going bad?

Any guidance is appreciated. -John