The boots on ball joints hold the grease in the ball and socket. They also keep contaminants from getting in the ball joint.
So a vehicle can have perfectly operating ball joints, they could be tight and not at all a safty issue, with bad/ripped/not seated ball joint boots.
How long will the ball joint last with torn boots? Could be a long time if you drive on dry roads with no sand or dirt.
Your best bet for now is to grease them often (every 1000 miles or less) with a water proof marine grease.
To correct the problem you will have to get new ball joints (they come with new boots) installed as the spindle has to be removed anyway to replace just the boots.
A word of caution when you get them replaced.
Make sure the installer gets the boots completely seated on the ball joint before completing the installation.
I have seen lazy or dumb installers replace ball joints without completely seating the boot on the ball joint. Water sand and dirt get inside and within a couple of years they need new ones again.
Also make sure they are replaced with high quality replacements... OEM, or Moog makes good replacements front end parts.
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