Bearing grease

So yesterday I took the SVX back in for new rear wheel bearings. I had them originally replaced in January of this year. About 6 weeks after that I had the car back in because the right rear bearing was growling. About 8 weeks after that bearing was replaced the left rear bearing began growling and was re-replaced. Now BOTH are growling. Personally I think I have been more than patient with these guys but I had to ask them what they thought the problem might be. The service writer (actually a very helpful person) said they had no idea. It was at this point that I asked them if they were greasing the bearings before installation. The guy said that the bearings come "pre-greased". I said I didn't think so, that the slimy stuff on them in the package was just preservative. I asked him to please check for TSB's on the matter and he said he would.

I think I recall a discussion on this topic either here or on the Yahoo board. Can someone let me know for sure if these bearings require greasing prior to install or if they are pre-greased. Also, if there is documentation for the greasing operation I'd like to be able to get a copy. They will be installing the bearings this afternoon and it would be nice to have something to show them about the procedure.

All help appreciated.