I remember reading years ago about an Indy driver that this happened to.. As I recall, he came out of turn two and was going like the hammers of hell when for some reason he pulled back slightly of the steering wheel and the universal joint came off the splines on the steering rack. He (somehow) just pushed the wheel back forward, the splines engaged just in time for him to enter T3... He pitted immediately where they found the grub screw laying on the floor of the race car.
It wasn't his time either - but it was most certainly his day!!!