Front axel boot leaks on occasion but not.

Front axel boot leaks on occasion but not steadily. Three years ago a repair shop showed me slight oozing at the boot clamp and said I needed a complete axle replacement for $1200. I said no since it wasn't even a drip. Had transmission fluid changed about two years ago. No comment about any leak at that shop. I have checked fluid level regularly. No noticeable loss. Now a couple days ago had a line of drips from center to left front wheel on garage floor. Cleaned it up. Not one drop on floor dor last three days.
Is the boot replaceable without removing axle? Can this possibly be resolved by simply tightening the boot clamp?
Any direction is appreciated.