Classic symptoms of steering problems will almost always include lack of control or response and clunky or jerky operation. As a driver, you would notice a grinding or stuttering feeling as you attempt to turn the steering wheel. You may also feel like there is too much play in the motion, making it seem like you have less control over the vehicle's steering. This isn't really indicative of any problem specifically, but you should definitely be checking for leaking power steering fluid at this time. If you see it coming from the steering gear box, then you've found the problem. Over time, the seals that keep the power steering fluid inside the steering gear box will leak or break. This causes a loss of hydraulic pressure in the rack, and you will be forced to turn your wheel many more times in order to make simple turns. It can become a more serious problem if you need to react quickly to avoid a collision, and you may not be able to move your car out of the way in time. So a leaking or damaged steering gear box is nothing to scoff at - get it fixed as soon as possible.
American automobile manufacturers were experimenting with power steering systems all through the first half of the 20th century. But it wasn't until after WWII that an efficient, durable, and cost effective method of providing drivers with a respite from 1:1 steering ratios became readily available. The first part to be added to the traditional steering linkage system was the steering gear box. It was located at the base of the steering shaft, and inside of it was a worm gear with recirculating ball bearings between the threads around which a ball nut rack travelled up and down. As the small rack moved up and down, the side with teeth would actuate a sector gear that turned left or right. That was connected to the sector shaft, then to the pitman arm, and finally the center or drag link. The steering gear box significantly reduced the amount of steering wheel turns required by the driver to turn left and right. Later on, the steering gear box would be permanently affixed to a rack and pinion, and the worm gear would be replaced with a simple pinion shaft that actuated the rack directly.
Changing a steering gear box can sometimes be a messy procedure. If you have hydraulically assisted power steering, you will have to detach your pressure and return lines with a line wrench. Make sure you have a way to capture the excess fluid that drains out. Odds are, however, that you would likely replace your entire rack and pinion rather than just the steering gear box. For traditional steering linkage systems, you will also need to pull the pitman arm off the sector shaft using a tie rod puller. Then, uncouple the steering input shaft from the top of the steering box. It is now ready to be unbolted from its mounting location, so go ahead. You can now replace it with a new gear box, and reconnect all the other components. Make sure all your seals are new, and replace any lost fluid or grease.
Most of the steering gear boxes you buy online today are going to be rebuilt. Occasionally, you may find a new one from an original equipment manufacturer like TRW, ZF, or Motorcraft. However; the majority of the steering gear boxes available are going to be rebuilt using all new seals, hardware, and bushings. At Car Parts Discount, we carry quality parts at super affordable prices. That means you are sure to get the part you need to fix your car, and it won't cost an arm and a leg.