Went to drive from a stop and heard clunk then it wouldn’t move. Goes into gear with and without clutch. When in gear it doesn’t move but the CV axles walking in its boot. The axle doesn’t move and the CV joints good. When looking where the axle goes into the tranny there’s two rings that move freely and sloppily. One of them has splines where the axle goes through it. What are those rings? Are they supposed to move or be stationary? And what is a possible cause and solution of this?