Mach 1 Transmission Whine

[brtnstrns]

I know at least a couple of you guys have had Mach 1's previously so I figured it was worth asking. The previous owner had the TR3650 rebuilt in this car with brass (I think - maybe bronze - whichever makes sense) synchros, spec stage 2+ clutch and maybe some other stuff but to be honest I'm not entirely sure. Anyway, 1st gear is fine, 2nd gear you start to hear a very very faint whine, then 3rd through 5th very very audible whine. It goes away when I press the clutch in or put it in neutral while coasting. I don't have any problems shifting through the gears and don't get any grinding or anything. Just the damn loud whining. I just replaced the fluid about 3 days ago (3.2 quarts) thinking that may be the problem, but obviously its not. Any ideas on what it could be? Or do I just need to save up the cash and have it looked at at a transmission shop and see if there is anything to repair? Thanks guys!