1997 Toyota Camry Suspension

The most likely suspect is a binding upper strut mount. To verify that, reach over the top of a front tire, wrap your fingertips around part of the coil spring, then have a helper slowly turn the steering wheel. You should feel the spring rotate smoothly with the tire. If the upper mount is binding, you'll feel the spring wind up and build tension, then suddenly pop free and turn.

The upper mount carries the entire weight of that corner of the car, so to make it easier to turn the steering, there is a small ball bearing ring in it. Dirt can get in it, or the cage that holds the balls can crack. The rubber center part of the mount can deteriorate too. That will allow it to settle so the body sheet metal drags on the mount.

You have to listen for where the ratcheting noise is coming from while a helper turns the steering wheel, but the upper mount can do that if the balls are running over dirt or part of the cage. The thumping is the extremely common complaint caused by the wound-up spring snapping free and turning.

The rack and pinion steering gear can cause a ratcheting or rumbling noise too, but that is much less common. Typically by the time it gets that bad, you've had a power steering leak for quite a while.

Sorry; can't help with finding a shop. We're all over the country. First you need to get a definite diagnosis. I gave you my best guess based on the symptoms. You wouldn't be happy with me if you had the mounts replaced and that didn't solve the problem.

The best place to go for this type of problem is a tire and alignment shop. Replacing the upper mounts requires removing the struts to disassemble them. That requires an alignment anyway. The people at those shops are experts at finding the causes of noises, vibrations, and bad tire wear.

Look for a shop that's busy. If the mechanics are standing around, there's a reason they don't have many customers.