got my new gears, packed it with grease and it runs very sluggish on the take offs, like its dragging a 10lbs weight behind it. I took the rear end apart and took out some of the grease I put in and it zips right along now.
I bought grease at wally world for 3 bucks, extreme pressure multi-duty grease (some lithium based stuff) and it should now go forever, well the gears in the rear.