Ok. Good to know. If you had damaged gearing, it would have been difficult to correct that issue.
Moving on.....this may not be the issue as well but it's worth a look at since it was unique to my CLD-D701. See this pic.....
The part I have circled is the ribbon cable assembly that connects to the laser pick-up. At least on the D701, Pioneer used double stick tape to place a thin plastic sheet on one side of it (maybe about 3" in length and 1" wide) to act like a stiffener to aid in keeping the cable taught as the laser assembly traveled back and forth. On my D701, that part came off and got dislodged on the cable and it started to affect the travel of the laser. I ended up removing the sheet and that kind of fixed the issue but I didn't realize it left a residual of the sticky tape. Hence, every time I played something, I would get an occasional jam up much like the sound you are getting now because the tape kept sticking to both sides of the ribbon cable. The final solution @ the end was to simply clean off that sticky gunk w/ some baby oil and after that I never had the problem again. Also, that plastic sheet was never re-installed and it probably was never needed as I have seen other sister models that never had it in the first place (so not sure what Pioneer was thinking)
Anyway, the symptom would occur on both A & B sides on my player so that is why I'm not sure this is your issue. However, just check it out by playing a disc and observe if the cable is flexing smoothly as the laser moves back and forth. Also, you might even see what the real issue is if it's not the cable getting jammed up. Keep us posted on your progress.