Question about lubricating wheel casters

[jgelack]

Hi, I was thinking about lubricating the wheel casters on my HF motorcycle lift table and dollie, and also a Lisle macanics creeper that I recently picked up. I can see that the casters came from the factory with a LIGHT coating of some type of grease on the bearings already. But I was thinking about adding a little bit more, probably just a spray white lithium. I understand that not all grease is compatable, so I was wondering if it would be necessary to remove the factory grease before adding the white lithium. I'd appreciate any advice you guys could give me.