Jerking movement in the front end

The multitude of symptoms suggest the vehicle has not had many repairs because it has been neglected for a long time. I can say the same thing about my daily driver, but I never ignore safety issues. It sounds like you have worn ball joints and/or tie rod ends. It is really rare for a wheel to fall off, but if a ball joint separates, that wheel and tire will squirt out, then get caught under the fender as you skid to a stop. If a tie rod end separates, that wheel will steer in whatever direction it feels like. You will drive into the ditch or oncoming traffic. All vehicles should have their steering and suspension systems inspected at least once every two years. One domestic brand in particular should have that done every year, and immediately when any clunk or other noise is heard.

The place to start is with an inspection at a tire and alignment shop. The people there are experts at finding the causes of noises, vibrations, clunks, and bad tire wear. At the mileage you listed, I suspect you are going to find a list of things that need to be replaced in the steering and suspension systems. If you list them here, I can help you prioritize them in terms of safety, comfort, tire wear, and redundancy. By "redundancy", what I mean is an alignment is needed after replacing most parts in the steering or suspension systems. It does not make sense to replace just some of those parts, pay for the alignment, then replace the rest of the parts later and pay for another alignment. Instead, have all the repairs done now that require an alignment, then do the other repairs later.

The anti-lock brake computer detected a problem, set a diagnostic fault code, turned the system off, then turned the yellow warning light on to tell you. Your mechanic will connect a scanner that can access that computer to read that fault code. That will tell him which circuit needs further diagnosis. An important point to be aware of is with most ABS computers, once they shut down, they stop running other self-tests. When someone waits a long time to have the first problem repaired, that gives plenty of time for a second problem to develop, but it will not be detected because those self-tests are suspended. When the vehicle is finally brought in for repair, the first fault code is the only thing the mechanic has to go by to calculate an estimate for the cost of repairs. He has no way of knowing there is a second problem in the system.

Once you approve of the first repair to the ABS system, and that is completed, the mechanic will always take the vehicle on a verification test-drive. That is when the self-tests will resume and the second problem will be detected. The yellow warning light will turn right back on, and the mechanic has to start the diagnosis all over again. At first he will assume he made a mistake in the first repair, but once he reads the fault code, it will become apparent there was a second, unknown problem. That is frustrating for him because he has to tell you there are more problems to diagnose. It is frustrating for car owners because they incorrectly assume the original problem was misdiagnosed or was repaired improperly. All of this can be avoided by having the system diagnosed as soon as possible before a second problem has a chance to develop.