case 2:
pinMode(sensorPin, OUTPUT);
digitalWrite(sensorPin, LOW);
delayMicroseconds(2);
digitalWrite(sensorPin, HIGH);
delayMicroseconds(5);
digitalWrite(sensorPin, LOW);
pinMode(sensorPin, INPUT);
sensorRead = pulseIn(sensorPin, HIGH);
This code belongs in a function.
Your robot will be flying blind while this code executes. A timeout on the pulseIn call would be a good thing.
We still have no idea what the servoCase, sensorCase, or steeringCase values are, so we have no way of knowing if they are correct/sensible. And, as PeterH points out, numbers don't convey a lot of information.
Your code has no comments. Not a one. That does not make for maintainable code.