scrootch under the car and look at the boots, if torn or leaking grease you need fresh ones.
Lift the vehicle using a jack. Inspect the CV boot for problems. Mark the axle. Separate the CV from the shaft. Remove the CV boot clamps. Use a mallet to knock the CV joint off the shaft. Remove the boot from the CV axle shaft.
The CV joint is the part inside the boot.
A CV boot is found on the axle of a vehicle. To replace the outer boot remove the axle bolt and pull the boot off. The inner boot requires removal of the whole axle.
A cracked boot itself won't cause a CV joint to make noise. However, a cracked boot WILL cause the grease to be slung out and allow dirt to enter the CV joint. And a contaminated CV joint that is starved for lubricant WILL eventually start to make noise.
They make replacements that are split in half, but they aren't generally recommended. What's best (unfortunately) is to remove the shaft and replace it with a stock cv boot. If the cv boot has been open to the elements for a while, damage in the cv joint might have occured.
Keeps dirt out of it
Check the "boot" for cracks and see if there is any loss of grease. The boot is the rubber housing around the CV Joint. If the boot is damaged, grease has escaped and the CV Joint is making noise, the CV joint must be replaced.
The rubber boot that covers the CV joint is what tears. When the boot tears grease is expelled and water and dirt gets in.
It is cheaper to replace the CV shaft than it is to replace the boot. If the boot has been torn for any length of time it will have collected dirt and water. That in itself spells disaster.
First signs of a bad cv is, clicking noise when making a sharp turn. Alot of times the cv boot ( rubber boot that covers the cv joint and holds the grease in ) tears and leaks the grease out, you can turn the wheel all the way and take a look at the boot where the axle attaches to the wheel if there is a rip you will see grease everywhere, if the cv isn't clicking yet it will soon.
The shaft should have a clip on it and you just have to give it a quick yank to pull it out of the CV joint then you can slip the boot on.
Changing CV boots is not cost effective. It is much simpler to simply swap in a rebuilt CV shaft.