After I first rebuilt my Cobra, including installation of a brand new front suspension and rack, there was a very small bit of play in the steering. Apparently the threads on the steering shaft at the steering wheel end were damaged and didn't allow the nut to tighten all the way down on the splined adapter. I always meant to address this but I saw it as more of an annoyance, and fixing it it was a little way down on the priority list. I used to tighten it up every once in a while and at times it seemed like it may have been getting a bit worse but complacency set in and I began to get accustomed to it.
Briefly, one day, I noticed a "squirrely" sensation in the front end while driving slowly. Afterwards, I checked all the fasteners in the front and rear suspension plus the shock mounts, control arms, steering shaft u-joints, wheel nuts and tire pressures. Nothing was out of spec so, against my better judgement, I concluded that it might have been either my imagination or something to do with the road conditions at the time.
Next day, heading out to dinner with my wife, some friends of my lil' brother pulled up behind us in a Supra that they used to give me a bunch of trash talk about . We were on a good, quiet, open stretch of road, so I decided to
learn them a bit of discipline 
. The Cobra bellowed and smoked the tires as I pulled away hard and held a good lead before it was time for both of us to start slowing down as we approached an intersection marking entry into a busier traffic area. They loved the rare display of the Cobra's fury and honked, hooted and waved as they exited and carried on.
Immediately after we turned left and accelerated slightly, the steering felt really strange, but went back to normal as we picked up a bit of speed. I slowed again and this time the steering was gone completely at idle speed - TURNING THE WHEEL HAD ALMOST NO EFFECT ON THE CAR'S DIRECTION!! I was barely able to guide the car to the shoulder. At a dead stop, the steering wheel turned freely on the shaft 90 degrees in either direction. The splines in the aluminum steering wheel adapter were almost completely worn flat from the constant vibration and back and forth movement allowed by the loose fit. As the last of the splines gave way, there was just enough grip left to turn the wheel at speed, but as the steering got heavy when I slowed, they went completely. If I had hit a pothole or made a sudden correction at higher speed earlier on...
Luckily, I was able to limp home steering with a pair of visegrips clamped to the column after I removed the steering wheel. Even more luckily, the steering hadn't chosen to let go at a time and place and speed that would have had some serious consequences. I'm also lucky that my wife is made of strong stuff - she took it in stride and still loves riding around in the little monster.