weird steering on corolla '99

A few days ago I was going over a bridge when my steering seemed to go kaput. The wheel turned by itself about 90 degrees, and there was no feedback (i.e., the wheel wouldn't re-center itself, felt like you could spin it around with a whirl). About 3 seconds later, everything went back to normal. Haven't had any problems since then. Took it into a mechanic, says I need a new rack and pinion. His diagnosis was that turning the wheels all the way to the right or to the left would make some noise (not audible from inside the car, had to be outside and near the wheels to hear it). Said it should be silent no matter how far you turn them. I asked a friend of mine who knows a lot about cars and he thought it was probably ice or something on the bridge. Anyone here know if this type of problem is actually related to the rack and pinion?

i'm guessing ice too. because if it did it on blacktop then it would still be so loose that you couldn't steer it. the rack will wear as anything else but 90 degrees of play is a lot of play.