I just had an X2 Power battery total warranty denied because it was brought in with less than 10 volts. It was 2.5 years old. I was not happy Batteries Plus called it battery neglect. So dont think I will get another X2.
Look in the yellow pages for your area under forklifts and call the independent repair guy. They know where to get the parts, usually local. I have some contacts left in Biloxi area.
What is the model? V50C D ?
I've built many axles and you are right about the mix and match. But I have never seen a set that wasnt marked with the lapping number from the factory with an engraver. Are there any markings on the pinion? should a least be a check distance on it.