I know there are a lot of people on the internet who really sound like they know what they're talking about and will tell you that you need to replace your factory 10.9 metric track bar bolt with a new 9/16" grade 8 shouldered one. And, I know there are even a few reputable vendors out there who sell whole grade 8 replacement bolts kits as if there's something wrong with all your factory bolts, BUT, I'm hear to tell you to NOT buy into the stupidness and save your money. Just because it's said on the internet doesn't make it true and let's face it, vendors are in the business of making a buck - they will sell you whatever it is you are willing to buy. Fact of the matter is, there nothing wrong with your factory bolts, they are the right size, they don't need to be shouldered and Chrysler purposefully put them on your Jeep for a reason.
To put things into perspective, you need to know that there are over 1,000,000 Jeep JK Wranglers out there on the roads today and 99% of them or more are still running these so called "wrong size bolts", for about the last 8 years now and without ANY issues. If all these bolts are really the wrong size, you would think it would be all over the news and some kind of recall issued by now. What the naysayers don't understand is that if bolt size were really the only thing that mattered in keeping things from moving around, there would be no need for torque settings.
Still not convinced? Let's take a closer look at how things work. When you look at the bushing of your track bar or control arms, the metal piece in the middle where your bolt will go through is called a "crush sleeve". AS IN, it's designed to get pushed really really hard from either end. The purpose of your bolts and nuts is to provide "compression" and cause your mounts to act like a vice by clamping down really really hard on the crush sleeve. The crush sleeves is NOT supposed to rotate AT ALL when installed correctly but rather, the bonded rubber bushing will twist around it. Of course, if you have a polyurethane bushing, heim or other aftermarket joint, the bushing will rotate around the sleeve or misalignment spacers - again, there is NO movement around the bolt and therefore, shouldered bolts are NOT necessary. This is the reason why bolts are rated for "torque" and NOT "sheer" - the value of compression strength is all that is necessary to hold things together. Don't believe me? Place a pencil between your index finger and thumb and hold it in the air. Why doesn't the pencil fall? I mean, there's no bolt going though your finger and thumb to hold it in place. Pinch it harder and it will even take effort to move the pencil around. Imagine that - compression alone made that possible.
If you really want to spend money on your Jeep, invest in a good torque wrench and use it as a part of regular maintenance.