kuuup

You need considerably more force to seperate the turntable. Worked for me without breaking anything. Next step is to clean them accurately. Read the 'Important' section of this moc: https://rebrickable.com/mocs/MOC-19517/Didumos/4wd-rc-buggy/#info. Didumos describes the right way to lubricate Lego parts.

See https://rebrickable.com/mocs/MOC-19295/Didumos/heavy-duty-wheel-hubs-for-claas-tires/#info for inspiration