Steering Wheel becomes Stiff While Driving
The reason why while driving sometimes the steering wheel becomes stiff is a problem on the steering pump or the steering belt is slipping.
Possible Cause why Steering Wheel becomes Stiff while Driving
Steering Pump is Faulty
This problem happens specifically on a car that is equipped with power steering. The power steering system is use to make the car steering more easily to steer when the driver rotate the steering wheel. All power steering system consist of a part that is called the steering pump, the steering pumps is the one that pumps the power steering fluid going into various tubes and valves which in turn creates hydraulic force that assist the driver during steering.
Since the steering wheel becomes stiff sometimes when the steering wheel rotates then the most likely cause of the problem is a faulty power steering pump this pump is occasionally failing. When the pump stop pumping power steering fluid for a moment there will be no hydraulic pressure causing the steering wheel becomes stiff for a moment.
Bring the car to a car shop and ask the mechanic to check the power steering system, explain to the mechanic about your diagnosis and have the mechanic confirmed that the problem is the steering pump, just replace the steering pump if necessary.
Power Steering Belt is slipping
Another cause of stiff steering wheel is when the belt is slipping. The belt has a tendency to slip when the belt is wet. Usually happens when the car is drive to deep puddles of water. However this cause of problem is rarely happen.
You can do nothing but wait for the belt to dry. You may try replacing the belt with a new genuine part to correct the problem.