There's a buildup of grease and dirt on the balljoints and around the area so there's a good one or both boots are torn. First, clean off the balljoints boots really well and inspect for any tears. If there are tears, that means grease has been able to escape and contaminants were able to get in. If either boot is torn, I'd just replace both balljoints.
If both boots are still intact, there's a good chance there's still ample grease to lubricate the joint. Next step is to inspect for play. Here's a video [MENTION=102606]infamousRNR[/MENTION] and I made for inspecting balljoints.
<iframe width="560" height="315" src="https://www.youtube.com/embed/rteeAOQlrKY" frameborder="0" allowfullscreen></iframe>
If you don't detect play, you can roll the dice and not replace them. But, what made me replace mine is reports from people who suffered a LBJ failure saying there wasn't any warning sign before it failed. They didn't notice any advance tell-tale play, clunking or noise leading them to believe something was wrong before it failed. And, some have failed at lower mileage than you currently have on your rig.
If you decide to replace them, [MENTION=102606]infamousRNR[/MENTION] and I also made a video for replacing them with all the part numbers and torque specs.
<iframe width="560" height="315" src="https://www.youtube.com/embed/bfLvtEnX9qk" frameborder="0" allowfullscreen></iframe>