I just recently aquired my first FJ40. I have a chevy sb with a stock 3 speed tranny. I just started driving it after rebuilding the front end, replacing the brakes, etc. On my first outing I noticed a loud roaring noise coming from the tranny?(I think).  oes anyone know what could be causing this horrible noise. *It stops as soon as I take my foot off the accelerator and starts as I depress it. Thanks