2004 Acura TSX Vibration During Acceleration after axle rep

I have a 2004 Acura TSX with a 6MT transmission. I started to get bad vibration during acceleration, starting about midway up the tach in 2nd and all the way through 4th gear. Eventually it got so bad it felt like going through a space shuttle re-entry. I got the front axles replaced, and the problem seemed solved for a day or two. Now I am getting the same vibration, but much less severe, and only in 2nd gear between 2000 and 2500 rpm. Baffling to me, but hopefully someone will have an idea for me.