GM 8.875" 12 Bolt 12P Car 30 Spline C-Clip LSD Limited Slip Differential

The GM 8.875" (often rounded to 8.9") 12 Bolt axle is available in passenger car (GM 12P) and truck (GM 12T) rear axle configurations and features an 8.875" ring gear and 30 spline semi floating axle shafts. While both versions of the axle have similar specifications on paper, they do have unique differential carrier housings and most parts, including ring and pinion gears are not interchangeable. Because both axles are commonly referred to as GM 12 Bolt axles, it is important to know which version you have before ordering your parts.

The easiest way to tell them apart is that the passenger car version has a perfectly round differential cover while the truck version has an irregular shape.