It was gear oil. Nothing to worry about, as it is normal to have it in the bearings. On a full floater, or any rear axle actually, the bearings are actually lubed by the gear oil in the assembly, it travells down the tubes to the bearings. The repack suggested in the manual is more of a pre-lube situation, and is a very good idea. I do it every time I have a rearend apart, full or semi float. You should check the fluid level in the rearend to make sure it is at the proper level.
