That sucks, but just a note: if those four bolts holding the final to the swingarm really have never been removed, it's not an alignment issue. You don't have to loosen them every time; if set in alignment from the factory, they're fine. I've loosened the 4 bolts only twice in the 84K miles on my Goldwing, to lube the drive shaft. The first time around 50K. Splines are perfect. Sounds like you had a lack of proper lube on the splines, and a bad seal around the spacer. Or someone's had it all apart before, in which case, yes, you gotta hate other people's work
