However, as I drove over the bridge, the Jeep's front end began to vibrate, and it got worse instead of damping out. I thought one of the front tires had come loose or something. The wheel jerked back and forth in my hands, and it was bad enough that you could feel it in your seat, and it didn't stop until I hit the brakes.
The pavement is smooth. I have never had any vehicle do that, large or small, old or new.
...so I have to wonder what the hell happened. The Jeep behaved properly for the entire rest of the trip--even when I went over the same bridge in the opposite direction--and there's nothing obvious wrong with the front end, either.
Somehow, I drove over that bridge at exactly the right speed and hit the expansion joint at exactly the right angle, and for some reason everything added together such that the Jeep felt like the front end was coming apart. Whatever it was, it was fricking scary.
So I--once I'm back from Maine--will put new shocks and a new steering damper in the front end and make a very, very thorough inspection of the suspension.