Changing the ball joints on your Jeep Cherokee can be a big job, but if you have the right tools and a little patience, you can do it at home. The ball joints support the outer knuckle, so if they are loose do not wait to change them. Failure of the joint can cause catastrophic failure that could lead to the wheel coming off the Jeep. You will need a ball joint separator and a ball joint press as the Jeep ball joints are a press fit, but if you don't have these in your tool kit you can rent them from many different auto parts stores.
Break the lug nuts loose on the front tires of your Jeep. Raise the front end of the Jeep off the ground with a jack and support it with jack stands.
Remove the lug nuts and remove the front tires. Locate the bolts on the back side of the brake calipers and remove them.
Remove the brake caliper from the hub and set it aside. Support it either with wire or string so that it is not hanging on the rubber hose.
Remove the brake rotor by pulling it straight off the wheel studs. Locate the three 12-point bolts on the rear of the hub and remove them. Do not use any thing other than a 12-point socket on these bolts or you may strip the heads.
Pull the hub assembly and axle out of the knuckle. If the hub has never been removed, you may need to use a chisel to separate the hub from the knuckle.
Locate the upper and lower ball joints. You will see a cotter pin at the base of both of the ball joints that needs to be removed using a set of needle-nose pliers. Discard the cotter pin as you will use a new one with the new ball joints.
Remove the nuts on the base of each ball joint using a large socket and ratchet. You may need a breaker bar to break these loose if they are corroded or have never been removed.
Separate the the ball joints from the knuckle by inserting a ball joint separator or pickle fork in between the knuckle and the ball joint and striking it with a dead blow hammer. The knuckle will likely pop off the ball joint very unexpectedly so be aware as you drive the separator in.
Set the outer knuckle aside after you get it off the ball joints. You will need to use a ball joint press to remove the ball joint from the inner knuckle as it is a press fit.
Position the ball joint press so that you are pressing the old upper joint up to remove and down to remove the lower joint. The press will come with many different size adapters so you will need to select the one that you need for your ball joints. Follow the directions in the kit to sort this out.
Clean in and around the holes with a wire brush before installing the new joints. Press the new joints in using the press again but this time press the top one down and the bottom one up until they are fully seated in the knuckle.
Slide the outer knuckle onto the new ball joints and install the nuts that came with them. You will need to torque the top castle nut to 75 foot-pounds and the lower to 80 foot-pounds. Install the new cotter pins and secure them by bending the ends around the nut.
Reinstall the axle and hub into the knuckle and replace the three 12-point bolts, torquing them to 75 foot-pounds with your torque wrench. Add a little anti-seize compound the knuckle where the hub installs to make it easier to remove in the future.
Reinstall the brake rotor and caliper onto the knuckle and tighten the two bolts holding the caliper. Reinstall the wheel and move to the other side of the Jeep. Repeat this process on the opposite side to complete the job.
Jack the Jeep up and remove the jack stands. Lower the Jeep to the ground and test drive it to verify everything is working as it should be.
