"Constant-velocity" joints are found at the end of each axle on most vehicles, including the Toyota Celica. These CV joints allow the shaft in the axle to continue to transfer power at a constant rotational speed without increasing the friction that is created when the vehicle turns corners. The CV boots keep the grease inside the bearings and joints of the "CV" system to ease the movement of the metal parts inside these joints. Sometimes these boots can crack, which leads to the grease inside leaking out and contaminants getting into the grease causing difficulty in turning corners.
Drive your Celica through the neighbourhood, taking note of the sounds you hear while turning your vehicle at corners. If there is a clicking sound as you are turning, the CV joint is already damaged and replacing the boot will not help. You will have to replace the entire axle, which as of January of 2011 is actually cheaper than replacing the boots alone on each wheel.
Turn the corners slowly as you drive. If you feel pulling or shuddering when turning corners, but no clicking sound, the CV joint may not be damaged.
Listen for the clicks as you are driving straight. If you can hear the clicks while turning corners and in long stretches without turning, then your CV joints are likely irreparably damaged.
Check your budget and price out the costs of the replacement of a brand new axle versus brand new CV boots.
Jack up the Celica on an elevated platform or on a jack stand. Remove the lug nuts using pneumatic drill or tire iron. Lift off the tires. Remove the brakes by disconnecting the brake lines and plugging them closed. Unbolt the wheel bearings and lift them off the axle. Set them aside.
Cut the metal CV boot clamps with a pair of wire snippers. Discard these metal pieces.
Use an X-acto knife or box cutter to cut off the old CV boot and discard.
Insert a small flathead screwdriver into the area where the snap ring secures the CV joint to the CV boot. Set the snap ring aside to use when you've replaced the boot to reinstall the joint.
Slide the CV joint off of the axle. Inspect this CV joint for moisture, or contamination. If there is contamination, the joints must be replaced as well. If not, set the pieces of the joint into a white spirit bath to clean the old grease off of it. Inspect the bearings in the CV joint for damage.
Slip the new CV boots over the axle end. You may need to use a small screwdriver to help in sliding the boot over the end by prying it up and over the larger parts of the axle. Fill the boot with new axle grease.
Fill the cleaned CV joints with new grease. The outer joints will have the large ball bearings in the joint. Use the outer grease for these and don't mix up the inner with the outer grease. Pack the grease into the joint and slide it onto the axle. Reinstall the wire ring you removed earlier and make sure that this ring is seated properly into the groove it was removed from.
Lift up on the far end of the boot with a small screwdriver to allow the air inside the boot to escape. Reinstall the boot to the joint by slipping on new boot clamps. Tighten the clamps to the boot and joint assembly. Some boot clamps can be tightened with a screwdriver; others need a special tool known as a Blue Point YA3080.
Use caution when working with the white spirit bath as the vapours are flammable. Do not work in areas with ignited tobacco products or open flames.