Input rollers misplaced

A hypothetical: Suppose, while placing the 833 mainshaft into the input gear, a roller is displaced. What's a guess as to how long it would take to feel/know/find out that happened?

I had my 833 apart 30 years ago and maybe made that error. The car is rarely driven..and rarely in this instance means considerably less than 1000 miles a year. I posted earlier about an 833 noise which may be the front bearing. Not referring to that thread here...isn't the point of the question.

If a roller gets nudged out of position, might that go unnoticed for a long time with such low mileage?

I did not consider my earlier disassy to possibly be the source of the noise I've got. Indeed, my recollection was that the 833 currently IN the car was NOT the same 833 that I took apart. I've pondered that I am possibly wrong about that.

I had zero problems placing the mainshaft back then. I moved the sliders around a bit, but the mainshaft went into place with no trouble at all.