Someone probably replaced it and the washer tabs didnít get staked or staked properly and/or the bolt head is the smaller type that doesnít stake well with the washer tabs.
The bolt backing out and falling out or backing out partially and breaking off has happened to several people over the years on both first and second gen. Serious safety hazard but no-one gives a crap. They keep putting the small-head bolts in the bushing kits - even the ones from the Chrysler dealers, or people just donít realize the importance of staking them at all and leave them unstaked.
I agree with first verifying that it didnít fall out vs. broke off. That of course would be the very best scenario. You would just have to get everything lined up to check for that and get a new bolt started. Itís hard to imagine the bolt breaking (vs. backing out all the way and falling out).
If it did break off, it would be difficult to get it out with the rack in the car. Hopefully the remaining piece is easy to turn and not binding.
Turning the steering wheel all the way to the right will give you the best access to the hole. Donít remove the other bolt until you have the problem solved. That will keep all the parts lined up so you get a straight shot at the remaining piece of the broken off bolt (thereís a metal block that is hidden between the rubber bellows/cover and the main rack rod with 2 unthreaded holes for the bolts - it slides back and forth over the main rack rod if both bolts are out at the same time - it can be a pain to get lined up with the two holes in the rack if both bolts are removed at the same time).
Assuming the remaining part of the bolt is loose and not binding, you could try to glue a small bolt or rod or tack a piece of welding rod onto it to give you something to turn it out with. Also, they make left-hand (CCW) twist drills that will turn it out as you drill (again, if it is loose and not binding). You would probably have to mail order the left twist drill (mcmaster.com, maybe Amazon?).
The problem on any of those methods is getting things lined up to hit the target without damaging adjacent parts. To drill, youíd need a right-angle drill motor (or adapter), and there may not even be room for that.
You could remove the rack to do the extraction on the bench using any of the methods described, and then re-install the same rack. A lot of work just to get a bolt out, but you may not have a choice.
If you do get to the point of putting a new bushing kit in, chances are it will have the small head bolts. Iíd highly recommend using blue thread locker on the bolts, in addition to staking. You can use channel lock pliers to squeeze and bend the tabs so they lie straight against the head all the way to the bottom of the head instead of laying at an angle and just touching the top of the head and doing no good.
Just curious to know if the tabs of the other boltís washer is even installed and staked, and if staked, is it even preventing the bolt from backing out.
'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs