240 1993 240 Odometer issues

I'm looking for advice / any fixes, I've replaced the odometer gear twice within the past 4k miles and it stops usually while trying to turn over more than 2 digits, like 99 to 100. Sometimes it sorts itself out but more often than not I have to replace the gear again

This thread should help you. Are you handy with a soldering iron? That is the path you are probably on. https://forums.turbobricks.com/showthread.php?t=350828&highlight=volvowagoon
There is also a lot of information on cleanflametrap.com.

I had the same issue on my 86, the replacement gear was just loose enough to spin on the shaft when there was enough resistance. I just put a few dabs of locktite on the inside of the surface and have it a minute to get tacky, reinstalled and worked for over 5k miles since. This might be your problem easy fix...