Is every np231 the same? Other than there's a 21 and 23 spline. Is there any electrical upgrades on the new ones? I have a 90 and the transfer case broke. The guy I'm buying one from says his has a plug on it and I don't think mine does?
The newer one have a speed sensor instead of cable driven speedo is hwat i hear. But if you have an SYE no issue or you could just swap the tailcones. Yes 21 and 23 spline difference between the AX4/5 and AX15 trans 4 bangers and 6 bangers.