Had AAM 3.73s and install kit installed in my 2001 formula by reputable shop owned by drag racer 2 weeks ago. At initial test ride slight whine was heard at 55 mph..now after a few rides to break them in (no launches) the whine has moved down to 30 mph with varying whine to 55. Any thoughts re why this is happening and how to get rid of it?
but its not uncommon for even the usually quietist gears even professionally installed to make som noise at certain speeds because of harmonics. sometimes they can be adjusted so a higher or lower speed so that it wont be as annoying.