50,000 odo working? 77,000 odo working?
I have read, and it seems so, that the pinion shaft is harder than the drive shaft. This is a good idea as the shaft is cheaper to repair or replace.
I had a Yamaha v star, which apparently had the splines replaced. I saw another one where both parts needed replacing. In both cases under 100,000km.
It's the old story, maintenance.