Brand used transmission

We developed a noise in our MR2 transmission and ordered one from a MR2 message board member in Texas.  We decided to remove the old one after the NEAT Rally.  When we returned, we removed the motor and transmission, cleaned up the new one and replaced the old.  To our dismay, the "new" one had the same sound.  After consulting with our "go to" mechanic, he agreed  that it was one of two things.  Either it had the same issue as the old one, or it is a noise that is inherent to the MR2 transmission.  Well, we decided to replace the "new" one with the old tranny and take the "new" one apart to see what we could find.  Stay tuned....We will take it apart soon and let you know what we find.  On a side note, we are really good at removing the motor and transmission, having done so about 12 times in the past month!