Autotrans noise that rises/falls with increasing/decreasing speed

[dman]

I'm hoping somebody out there has experienced this as I have invested a significant amount of money in restoring my 89 900T16 Auto. The car gets praise from every Saab mechanic I take it too, but it still has some annoying problems.

The problem is a low-pitched growling noise that seems to be coming from the transmission, since the noise rises and falls according to how fast I am driving.

Below 35 mph it can't really be heard, although its there, but between 35 and 45 mph it becomes very noticeable. Above 45 mph the noise seems less noticeable but that's because the noise from the turbocharger seems to go up at that point. Above 45 mph it's not much of an issue. The noise from the turbo is another story.

I took it to the local saab dealer and the mechanic I spoke to took the car for a spin and when he returned told me it was just the torque converter winding up and down as the car accelerated or decelerated. He thought given the car's age that the level of noise seemed normal, but I'm not convinced.

The funny thing is, if I slip the transmission into neutral, the noise is still there and rises or falls according to whether I'm accelerating or decelerating.

Has anyone else experienced this problem with their autotran 900s?