I guess I know how they break - twisting them too hard. What I really mean is, what is the point of failure? What is the weak link?

The outer CV shaft that goes into the hub sheared off in my case. Are there other points of failure experienced? Outer CV bearings? FFR provided axle shaft snapping? Inner CV joint failure? Something else?

I will assume there is a range of parts quality from cheap ebay parts to some source unknown to me that makes super strong 1000hp high end professional race car parts. If you've had an axle failure, please share the perceived quality of your parts. If you have higher end / strengthened axles or CV joints, please share.

Factory Five currently sells the FFR axle shaft for $95. And they sell a complete axle with both CV joints installed for $159. $64 for two CV joints installed - I'm gonna guess those CV joints are on the extreme low end of the spectrum. The build manual suggests parts from AutoZone.... I believe the original purchaser of my kit bought the complete FFR CV installed axles. $110 for the pair in 2017. I suspect the CV joints are of the lowest AutoZone quality. Is it enough to rebuild with Subaru OEM CV joints?

I'm trying to figure out my strategy for fixing my broken axle. And give the same treatment to my unbroken axle. And have a spare. Hearing from others about what has failed and what has been working on a track car or maybe even more relevant, an autocross car would be most helpful in coming up with a plan.

axle broken.jpg