Steering gear or pump.

find a shop with ears, we have none

just like gold it is found where you find it.
noise parked , is x100 times more safe and easy to find than only car moving nose
use card board tube on ear and walk everywhere and find it>?
first places is underhood, most time.
get the car serviced in a real shop, and be safer?

it indicates that when the pump gears are placed under pressure /load that they are interfering with the pump housing or are not being held in the correct mesh situation
the situation of powers steering that when in the relaxed position ( no steering wheel movement) the valves are so placed that the oil is by passed straight back to the reservoir but any movement of the wheel closes those valves and diverts the oil to the cylinder/actuator and so power assists the steering
AT this point is when load is applied to the pump and the noise is heard
I would suggest that the pump be removed and inspected for wear on the idler gear shaft, wear on the tips of the teeth from contact with the housing
Mostly the best fix is a replacement pump because it the clearance between the teeth and the housing is excessive or scored then the full pressure will not be achieved

Obviously your done

Tow it to a shop

You can not steer it ,you can not use it !!

hi Eva.
As you turn your steering wheel it is this fluid pressure that aids in turning the wheels of your car. ... If the pump impeller is trying to move power steering fluid and starts catching air bubbles it can cause whining noises and vibrations to occur.
Maybe you've heard it at a stop light. Maybe you've heard it as you pass a car on the freeway. Or maybe you've heard it in the parking lot at work when someone is leaving. The unmistakable whine of a power steering pump can make even the most confident mechanic wonder when that car will breakdown.
Power steering pump noise is a unique noise that your car may make and once you've heard it you always know what it is. The noise is a mix of a whirring and a whining and will always vary with the speed of your engine whether your car is driving or in park. This whining noise can be subtle or extremely loud and may be worse in colder weather, or right when you first start your car.
Power steering pumps are most often vain style centrifugal pumps that are tasked with pressurizing the power steering fluid and pushing it down to your power steering gear or rack. As you turn your steering wheel it is this fluid pressure that aids in turning the wheels of your car.
There are a few reasons why you are hearing power steering pump noise from your car. First, it may simply be due to the design of the pump. Sometimes, noisy power steering pumps can continue to work flawlessly for years after they start making noise. This may simply be due to the manufacture's design or a tight tolerance in that particular pump. In this case, you would hear the noise but not see any other adverse effect like a loss in power steering, leaking fluid or a wobbly pulley. In this case, you may be able to help reduce your power steering pump noise by choosing a different type of power steering fluid, like a synthetic fluid.
Your power steering pump may also be making noises due to air trapped in the system. If the pump impeller is trying to move power steering fluid and starts catching air bubbles it can cause whining noises and vibrations to occur. Even tiny air bubbles you cannot see that are trapping in the power steering fluid may be causing the whining you are hearing. In this case, the best thing to do is flush your power steering system to try and remove the air from the system. Having air trapped in your power steering system can be difficult to diagnose so you may need to simply try a power steering flush to see if it solves your problem.
Power Steering pump noise may also be due to a failing power steering pump. As the bearings on the impeller go bad it will start to make noise as the pump is turning. If you have a bad power steering pump you usually will also experience leaks from around the pulley, a wobbly pulley, or difficulty turning the steering wheel when you are stopped. If you have multiple of these symptoms together, it is probably time to replace your power steering pump.
Lastly, and most usually, a whining power steering pump is an indication of a low fluid level. Your power steering fluid is probably something you have rarely if ever checked, so it often comes as a surprise if the level is low. Your power steering fluid reservoir is also relatively small so even a slow leak will cause a low fluid level relatively quickly. To confirm this is your problem it is as simple as checking your power steering fluid level. Some power steering reservoirs are clear so you can see through them to check how full they are. You may have to wipe away some dirt and grime to find the "full" line, but it should be easy to check. If you have an opaque power steering fluid reservoir there should be a small dipstick under the cap that will help you measure the fluid level. If it is low, then you have a leak somewhere and topping off the fluid should quite down your power steering pump.
If you discover a power steering leak, rather than simply continuing to add fluid every time it gets low, you should fix the problem permanently so you don't have to continue to check your power steering fluid level. Replacing lines or seals can be a surprisingly difficult task due to the location of your power steering pump and steering gear or rack. The easiest way to seal your leak is to do it from the inside out!

or check this link out for more info on this matter.
Power steering whining sqreeching Google Search

It's not unusual for these pumps to make a whining noise when under high load, such as at end of travel of the steering links. Yes, the gear box could be part of the problem, but first I would carefully check all the steering linkage tie rod ends - one or more of them could be badly worn or stating to seize due to lack of lubrication.

Problems associated with low power steering fluid…

Hard Vehicle Steering
A low power steering fluid level can often times cause a vehicle's steering to become hard and labored. Adequate amounts of power steering fluid are necessary to enable a vehicle's power steering system to function and operate at optimum levels. A lack of power steering fluid in a vehicle's power steering system reduces the amount of hydraulic fluid pressure necessary to efficiently operating the various parts of the entire power steering system. Power steering fluid supplies the fluid force needed to operate the power steering gears and to enable power steering gearbox operation. Low power steering fluid levels reduce this hydraulic pressure, which commonly results in hard vehicle steering.

Pump Noise
It is very common for a low power steering fluid level to cause significant power steering pump noise. An adequate amount of power steering fluid is required to ensure the proper function and longevity of a power steering pump unit, which is a belt-driven pump responsible for housing and circulating power steering pump fluid. A low level of power steering fluid results in increased power steering pump friction, heat, and wear, all of which can significantly reduce the operational life of the power steering pump while at the same time cause excessive power steering pump noise.

Fluid Boiling
Many times a low power steering fluid level can result in excessive heating of power steering fluid, a condition that can seriously degrade the fluid and cause it to boil. A low power steering fluid level results in less available fluid to both lubricate and cool a power steering pump unit. A lack of power steering pump lubrication and cooling leads to excessive heat being generated within the power steering pump unit itself, a condition that translates into the available level of power steering fluid becoming super-heated and degraded. When this happens it is common for the power steering fluid to boil and lose all of its lubricating and heat-reducing capabilities.

Gearbox Wear
The power steering gearbox is a set of gears within a vehicle's power steering system designed to facilitate movement of a vehicle's front wheels. The power steering gearbox is connected to the power steering pump by hydraulic fluid lines that deliver a constant supply of power steering fluid to the power steering gearbox. A low power steering fluid level, especially a chronic and severe low power steering fluid level, can lead to increased friction and wear within the power steering gearbox assembly, a condition that can significantly shorten the operational life of the power steering gearbox and negatively affect its operation

Area of interest...power steering pump and power steering pump belt. Check fluid level in the pump.
Check belt tension.
One of those "fixes" should stop the weird noise.

If the pump fluid level full?

Believe it or not there are some problems you should take to the dealer. It never was the gear box, its a defective steering column bushing. That problem had a factory notice and the dealer would have diagnosed it immediately an fixed it free parts +$40.install. Tahoes get that problem.

Check for low power steering fluid. If the Fluid is at the proper level. "DO NOT OVERFILL". Then Check that the Power Steering Pump is working. Is the Serpentine Belt On the Pump Pulley? When you start the engine does the pulley spin? DO NOT TOUCH IT WHEN THE ENGINE IS RUNNING!!!
Do you get any Weird Noises when you turn the steering wheel?

I am focusing on the Power Steering Pump because if the pump is working properly there really isn't much else that could cause hard steering.

Good Luck.