I'm having an odd problem that I'm not finding elsewhere on here or other forums. After replacing the rear axle assembly in my '91 sedan with one from Southern Vo-Vo of Tennessee (both labeled as 3.73 gear ratio), my speedometer is reading ridiculously high; if I'm going about 5mph, it's reading 40mph, and if I'm going 40mph, it's pegged at 120mph. It jumps around here and there, sometimes going down to 80mph or so, but it's usually pegged while I'm driving. The replacement axle did appear to have ABS brakes originally, which was apparently an option in 1990, but other than that everything fit together without issues. Is there a way to re-calibrate the speedometer or speed sensor? It's putting a lot more miles on the odometer than I'm actually putting on the car. Any suggestions?