I ended up giving up trying to get front shaft into my old transfer case, I bought a new shaft and rebuilt transfer case from
https://www.tcbmwx5.com/
check your splines, if they look like mine below, you need a transfer case. 4 hours of filing did not work due to the first inch of splines were half broken off and the torque kinda bent them, no way to get it in. 4 days of trying and figured with 260k prob worth it to get a rebuilt. Plan on keeping car for another 5 years so will see.
after filing for 4+ hours with small flat and square files.
