TC02C diff issues

[dicky14]

Might be a daft question (usually are), having replaced my diff balls with hpi ceramic items ive noticed the diff slips more than with steel balls, ive used wet and dry on new diff plates and the diff started slipping(this was after running in the diff) i swaped the diff plates over and repeated the process( it lasted 3 races and chewed up the plates) i've since built a new diff using standard parts and so far so good. What have i done wrong? Its not like i'm a novice with this kind of thing.