Was drive along, as turning a corner, my engine revved up and I was no longer moving. Nothing appears to be wrong with the CV joints, won't move in any gear.

So I am thinking transmission, so I have to ask, how hard would it be to swap it.

It's an automatic trans, in a Mazda 323, 1990, Sedan.


Any thoughts?

 

Sounds like the transmission is slipping. Check the fluid. Does it look black? Smell burnt? It's not too hard to change on a 323 if you have fairly decent mechanical knowledge and tools.

The CV Joints are unrelated to your problem, it would click a lot going around corners if they were bad.