Do your tools have a drive gear ? It is possible the gear is binding with the turret drive gear causing heat. Check backlash/ gear play by rocking to tool back and forth after clamping the toolholder in the turret. There should be a little discernable free play in the teeth. Make sure the tool rotates freely without binding after clamping in the turret.
If the toolholder and tool has through tool coolant, make sure the plug is removed and the o ring is in good condition, if not it may wash grease out of the bearings, or fill the turret live tool drive with coolant.