Well this DOES remind me of an "old story."
In my Navy days I had who would become a good friend in San Diego. This was 70--71, I had my 69 383 RR, and he had a new Chev 3/4T 4x4. Somehow we both got the bright idea to go down and buy white cue balls, drill and tap, and make shift knobs. WE LOVED THEM
It ALSO turned out.........that either because of the material, AND the extra deep hole we'd drilled, the ball would "make noise" and conduct transmission noise, somewhat of a "sound" into the car.
One day he had his stocker knob back on, and we discussed it. I left my cue ball knob.
Now it ALSO turned out that the mainshaft ball bearing in my 69 was starting to disintegrate, and I was not smart enough to realize. I just thought it was "the ball." Eventually, one of the balls broke, etc, broke the ball retainer? and allowed the entire mainshaft to shift back and forth in the gearbox. This destroyed:
The needle bearings in the pinion gear, the inside of the pinion gear, the nose of the mainshaft, and......just to finish stuff all off nicely, a chip of "something" went "through" the two mating gears on the pinion / cluster.
Yup. It was a mess.
BUT................."we" were not done, yet. "San Diego Metalspray" talked me into (the mainshaft was backordered) that they could repair the nose of the mainshaft. They ended up cutting it down and putting a "hardened collar" on the nose of the mainshaft. Young, stupid me, put the whole thing back together.
The "hardened collar" was NOT. Hardened, that is. It proceded to destroy the new needle bearings, as well as the inside of the new pinion gear. So the gearbox had to come apart AGAIN.
It got so bad that one of the division officers asked me why my RR was spending so much time "with the front wheels off the ground"