ok i have a V3 STI and im tying to fit a uk spec rear diff,,,,,, but i cant seem to get the shaft to lock into place no matter how hard i snap it

seems like the snap ring wont go but just wondering if the shafts are different and thats why its not happening

this is on the passenger side and its the inner CV joint,,,, just wont seem to "click"

anyone able to give me advice ?

 

also should the C clip be in the diff or on the shaft ?

the drivers side dont have a snap ring but the passenger side did ?