There is upgraded parts to replace those funky cheap parts, Ive seen it on the HPI website. I remember when I bought my first RS4 3 RTR it realy sucked to when the hub wore out and it will break my dogbones so I replaced the hub part with the ones that belong to the 18ss (shiny ones) and it worked just fine and dont wear out. But that black parts HPI made are cheap. If you want to save you some money for a wile you can rotate them around where you will wear out the other (or shall I say the oposite end).
Or use these from HPI at the tower....
http://www3.towerhobbies.com/cgi-bin...?&I=LXDHU4&P=7


Here is the set of the cheap black cup joint and the better stronger shiny steel.