RE: .28 in a funfactor? oh dear....
You might want to run a tighter mesh on the pinions. I know that CEN said that the tight mesh idea was posted as a fix for the Genesis but I don't think they realized that you were running a .28 in your MT2, which will cause chassis flex and vibration more so than the Genesis. The bearings might be over heating because of the clutch slipping but they still should have lasted longer.
Ask Auto2 about how he managed to get his pinions to survive. I don't remember him complaing about them. He might of been using a single speed though.
rolland