You can cheat and dimple punch the hub and red loctite the bearings to it. That works pretty good. The main reason they get loose is the knuckle bore is soft and once the races start to move you get the loose wheel. I don't care how well you grease them. In 1974 we went to a school and there was supposed to be a service kit available with selective rings to go between the races. There was also going to be tools to set up the bearings with the correct ring to obtain a stack height. That never made it as testing was now showing the flaws in the system. Mopar had a quota commitment from Dana on this design. That why it made it the 4 to 5 years. By the time 1977 rolled around the customer confidence and satisfaction of that design was well down the tubes.