You probably can't buy a new one unless it is old stock. Your best chance is going to be eBay. The carbon fiber shaft is very light but it is not stronger than aluminum. The ends are basically glued to the rod. It is possible to snap the ends right off under hard acceleration, especially with hi torque brushless motors and advanced speed controls. I did. I have a carbon fiber shaft now but I only use it in my USVTA car where torque and acceleration are pretty limited. I don't know if one was ever made for the TC4, only the TC3. And yes, the drive shafts are slightly different for the two.