There will be a little play in the axles, that's ok. The axle surface that is contact with the seal should be smooth, that's the main thing. I have never put grease on an axle seal and never had had a leak from them. I don't think it's appropriate to grease them.

2gnt: '99 RS-T, killed by a toyota, pending rebuild...
Daily: Volt
Daily #2: '99 EVG ebike- STOLEN by PEDRO