Most trail rigs have U-joints, so why are we messing with CV joints, and more importantly, why are we talking about them?
It's a simple answer, really. There are still plenty of trail rigs that do, in fact, use CV joints. Toyota solid axles use them; they're called Birfields. IFS rigs use them, and some Jeep Dana 30 solid front axles came with CV joints instead of U-joints. Finally, the Jeep JK uses CV joints in its stock driveshafts.
Using CV joints in the JK driveshaft was actually a poor choice, and most JK owners end up replacing their CV joint drive shafts with U-joint drive shafts. That's another story for another day, though.
First, we'll delve into how CV joints are taken apart.
We'll assume that the CV joints are removed from the vehicle, and that the axle shaft is either removed from the CV center star, or that the axle shaft has been cut off close to the CV joint because it cannot easily be removed. If you have to cut your axle shaft, you'll of course have to purchase a new one. In this case, the axle shaft was being replaced with a custom extended shaft, so the stock shaft wasn't going to be re-used.
First, place the CV joint in a vise with the open end pointed up.
Next, use a brass punch to tap on the cage (we tapped on the cut-off axle shaft in this case) until the 'window' opposite the punch rises up to reveal one of the six balls. Remove the ball from the window and set it aside. Repeat this process until all six balls are removed from the CV joint.
Before you remove the cage and the center star, clean off a small patch on each of them and use a pen to mark the side that faces up. Neither the center star nor the cage is symmetrical, and it can be difficult to tell which end is up. Futhermore, the CV joint cannot be re-assembled if the cage or the center star is facing the wrong direction.
After the cage and the star are marked, take the cage with the star inside and turn it up 90 degrees. Place it inline with one of the ridges between the grooves and turn it slowly while trying to lift it out. You will eventually find the sweet spot that was designed to let you remove the cage and the center star from the outer CV bell. Do not try to force the cage and center star out of the bell. When you find the correct position, they'll come out easily without being pried.
Tune in tomorrow, and we'll continue.