Need some EXPERIENCED drivetrain guys to comment.
 

Okay. Lets explain. Blew the old transaxle to pieces. Built up a new one with aftermarket internals, hardened output shafts (both) cryo gears, DTE brace, the works... After the install my passenger side started to leak diff fluid, getting slung all over the place. I immediately replaced the output shaft seal, and it still leaked. So, this last weekened I tore the entire transaxle back down, and replaced EVERY seal exactly to GM spec with painstaking attention to detail and all of my automotive knowledge. Still leaks. The seal itself has been replaced 3 times, no changes. The case is NOT leaking, it is certainly without a doubt coming from the halfshaft/output shaft seal. the ONLY thing I have no done is replace the halfshaft... after that I can no longer fix this problem, everything has been replaced.

Is it possible that a LPE short shaft could cause in some fashion a leak? The shaft appears to be centered in the diff, and I dont have any abnormal wear in any of the seals or the metal of the seal. The halfshafts both have small groves in them but shaun from lingenfelter told me that is normal, and just after 5k miles you start to see groves... my other side had this as well.

Is it at all possible to misalign the halfshaft? Do they ever become damaged and out of balance causing a leak?

I know it cant be the seal itself, it has been replaced to much. It is not the case leaking, I've resealed it twice correctly and same result. It dosent appear to be a breather or vent issue since I've checked the breather and it appears fine, and the driver side does not leak at all. The differential makes no noises or anything out of the ordinary for a completely normal drive.

Put a caliper on the output shaft where it mates to the seal. Then compare to a stock shaft to verify if there are any machining differences.

yeah I've mic'ed it all, everything comes out legit in that fashion.