I have a 1998 F150 XL, 4.2L, rear wheel drive with 225K on it. I've heard a knocking and squeaking coming from the passenger front wheel. Thinking it may be a bad shock or bushing (which may be the case, too), I also took a pry bar to the lower ball joint where it connects to the steering knuckle and found a lot of slop. My question is...can you replace this joint alone or do you have to replace the whole control arm? O'Reilly's has a bunch of joints listed but when I looked at a Chilton or Haynes it said this joint was an integral part of the control arm and the whole control arm should be replaced. Thanks.

 

The individual lower ball joints are replaceable even though Ford set up the repair as a replacement of the whole control arm. I did a number of them on my old 97s when I had them. Instructions are on this site, look in the faqs or relevant tech folders.

 

Yup, you can replace just the lower ball joint, not too bad, but make sure you get the ball joint press tool (parts stores will lend them out for free with a deposit). Lots of how to videos on you tube (most are for 4wd, but 2wd is pretty much identical, even easier since you don't have to remove the front shafts). Check the control arm bushings though, if they are bad, it is easier (and around the same price) to just replace the whole lower arm. Most will agree to use Moog Problem solver Ball joints (around $20-25), but they do require periodic greasing, so you will need a grease gun. Many others will just stick with OEM, they cost a little more, but work and last a long time.
The upper arm and ball joint are one piece and need to be replaced as a unit.
If your doing the lower, do the upper also, and do both sides.

Moog upper control arm numbers (for a 2wd):
Drivers side - CK8726T
Pass side - CK8728T
ball joint (both sides) - K8695T

 

Thanks blu. No more knocks or squeaks! I got a lower ball joint and replaced it using the press tool I got from the parts store. Found the upper joint was just as bad as the lower, if not worse, and replaced the control arm. Jacked up the driver's side but found very little slop in it. Will have to do at a later date. Gotta do a brake job on my daughter's S10 and find out why it is making a popping sound when she backs up down the driveway and turns onto the street. I know she needs a new tie rod but may also have bad wheel bearings or a ball joint, too.

 

Yeah, if one side is bad, the other will not be far behind. If it is not bad, it can wait, but it will need to be done sooner than later.