When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Today while driving I noticed a knocking when turning right or going over bumps in the road. I finally got to look under the truck and noticed that I'm missing the nut on the top side of the front stabilizer bar link bolt assembly on the passenger side.
Obviously, it's knocking because something is loose and hitting another part. It would be unsafe or could damage something if whatever is doing the knocking gets caught on something else. Look at your "good" side to see what things are supposed to look like.
A non-functional sway bar isn't unsafe by itself. It would just allow the handling to be wishy-washy (which could be unsafe).
The fluid you see on the lower control arm is power steering fluid that had leaked out of the rack, apparently as result of some added stress or pull on the tie rod, which I assume was related to the broken link. I say that because, after I cleaned off the fluid and replaced the links (I did both sides), the leak disappeared - and I haven't seen any sign of it since.
So, based on my experience, I recommend fixing the problem as soon as you get a chance.
I got my replacement links from Ford; IIRC you can also find something that'll work at most auto parts stores.
FYI: The Ford Manual says to torque the OEM link nuts to 21-29Nm/15-21lb-ft.