Today while I was at my mechanics to install new struts on my 89 745T, I also had him try to locate a noise that sounds like bad bearings somewhere. The noise occurs at about 2000rpm. Over the weekend I removed the console cover and noticed the noise now seemed much louder. We put the car on the lift with his assistant in it to rev the car to 2000rpm. The noise seemed to be coming from within the bellhousing/ torque converter area on the drivers side. We removed the trans/block brace, checked for loose torque converter bolts. Nothing loose, no foreign objects. We confirmed that it is not cat, downpipe, or heatshields. We had a transmission guy located 2 doors down observe the noise and drive the car. He acknowledged the sound seemed to be coming from within the trans, but said it he would suggest unbolting the converter and separating the trans from the engine enough to start the engine without the trans connected. This way he could be certain it was the trans. He is not totally convinced that it is in the trans.
So what in the trans could make this sound? Could a clogged filter cause or contribute to this sound? I have been fanatical about servicing and repairing this car. Trans has been flushed at regular intervals. Car has 141K. I got the car with 58K. The trans has a rebuild tag on it indicating that it has been replaced once already. Any words of wisdom would be greatly appreciated.