Here's my story--I have a '92 in the snapring range and it has shifted as smooth as silk. I decided to inspect the snap ring myself this past weekend and found that it's been boroken--for how long, nobody knows. There were pieces of it sitting on the treaded area of the inspection hole. So, I'm now wothout a car until it's repaired.
My main point here is that one can have a failed snapring and have no symptoms at all, like my car. There is still much of the ring left on the groove and perhaps that holds things in place for a time. My recommendation is to not buy a car in the snapring range unless you have it inspected ahead of time--unlike me.