There are quite a few threads on this subject. Use the search function on the home page to find hours of reading enjoyment.
IMHO, if your CVs are making a noise, it's too late for them. Better start thinking about replacements.
The good news is that CV boots (even half shaft) replacements are well within the capabilities of a shade tree mechanic (I know 'cuz I are one & I've done it).
My boots gave up the ghost when I was about 200 miles from home. By the time I got home & replaced the boots & repacked the joints, it didn't do any good ... CVs were toast.