Disclaimer: Links on this page pointing
to Amazon, eBay and other sites may include affiliate code. If you click them and
make a purchase, we may earn a small commission.
That is the inner race for the CV joint. There should be a large ball bearing for each of the grooves and a metal cage that holds it together that appear to be missing. It is known as an Rzeppa joint if you image search you will se what they are supposed to look like.