VPI Platter Spinning SLOWLY

I've tried two different lubricants (Super Lube and Shimano Dura Ace Grease) for my VPI Classic 2 platter and it still does not spin properly. I removed and re-applied grease and it spins fine for about 5 minutes, then it slows down immensely. If I remove/re-install the platter, it spins smoothly again but only for a short period of time. Anyone experience this before and know a fix? Thanks