The bolt is loose. Tighten it up. It's under the horn cover.
Loose column, worn linkage, etc.
Bad tire, wheel, bearing, steering component,..............
Any number of things can cause a steering wheel to shake back and forth. It could be a bad wheel bearing indicating a wheel is about to fall off. It could be a bad tire or bushing. Without checking it out personally, I can't tell.
If you have the steering wheel turned at an angle it could cause the locking rod to the transmission to jam or stick. Try wiggling the steering wheel back and forth a little.
Your power steering pump and or steering box may be about to give out on you.
Have someone rock the steering wheel back and forth as you inspect the steering linkage for loose joints.
To turn the rotary motion of the steering wheel into a linear (back & forth) motion that can turn the wheels.
The Steering Wheel lock is jammed! Gently wiggle the steering wheel back and forth as you try to turn the ignition key.
Keep jiggling the steering wheel back and forth.
Major vibration in the steering wheel. With the car parked and the steering wheel unlocked, go to a tire and try to shake it back and forth by grabbing on each side of the tire. If that tire will move back and forth, the wheel bearing is bad. Also when drivingand turning in curves, if the roaring gets louder, they are bad.
The Steering Column locks the wheel in place and when the steering wheel is locked you cannot turn the key... try turning the key with gentle force while turning the steering wheel back and forth.
When moving the steering wheel back and forth in a commercial truck, the component that should be turning is the steering gearbox or rack and pinion system. This mechanism translates the rotational motion of the steering wheel into lateral movement, allowing the vehicle's wheels to turn. Proper functioning of this component is crucial for steering responsiveness and safety. If there's excessive play or difficulty in steering, it may indicate a problem with the gearbox or related steering components.
Turn the steering wheel back and forth if that doesn't work try that screw under the steering column