I have weird sound coming from my box. I'll explain:

When I take of from either loading up, standing start or a slow roll, and accelerate at a moderate rate, I have a vibration through the driveline along with a noise, which I guess is the vibration. It phases out after a certain speed about 45kmh. Im told by a few people its the torque converter. The fins inside are either loose or broken free.

Also a strange thing is that when I manually shift down to any gear, it seems to drop into neutral, but when I accelerate, it falls back into the slected gear and pulls, however lay back off the throttle and it drops back into neutral, and so on. Whats going on here?? Its drving me mad. Help!!!!!!!!! Remember, its a 94 NCII Fairlane 5ltr Backed by the 95LE.

Cheers,
BBII

To me, the first problem definitely sounds like a stuffed converter.

The second issue is you have stuffed the part that is used for decellaration. I can't remember what it's called, but it's something like the sprag sprocket or something like that! Basically though, your gearbox will be fine while accelarating, but it won't be able to offer decellaration.
Generally happens when you shift down too hard too often, while decellarating.

what model car is it get under the car with it on stands neare the auto the isa little flap move it back and see if the bolts are loose or if the coverter is stuffed

i had somethign similar in my old box ( i bought new one and rebuilt ) it turns out with mine that it was actually the internal hydraulic clutch type thing inside my box had lots of metal shavings in it