Yeah i've had to replace a main shaft before. It was an old and battered item. Scored horribly from the servo ears and from various wires that rubbed it.
Some good long hrs of use with a novak ss5800, and then a GTB 5.5 resulted in a shaft that was wobbly and caused vibrations. Even worse, the pins on the end did not line up! (looking down the shaft) The actual shaft itself had gained a twist. Talk about power...
so in went a new one and some alu centre drive cups. Very smooth and wobble free now.
BrainTeased - i go by AngryAsian because my name is a bitch to spell and say. LOL.. Name's "Phoebus".
Say the first part of Phoebe - then add the bus... like "Fee-bus. "