i just had my transmission in to be rebuilt and the mechanic said he had to replace the torque converter because it was busted. he also said he has never seen this on a GM. how does this happen? and not being that familiar with automatics, what exactly can it effect? what does putting an aftermarket in do for you? thanks

 

I don't know what he means by busted, but the toque converter clutch does wear out and it requres that the whole torque converter be replaced. The torque converter itsef can also fail for many reasons, but not as often ad the TCC. In any event it is a good idea to replace the torque converter whenever the tranny is rebuilt. Debris from the failed transmission can collect in the torque converter, which cannot be properly flushed out withot splitting it in two, and gets circulated in the new tranny and makes it fail. Also make sure that the transmission cooler and plumbing are thoroughly flushed out, for the same reason.