Thread: 10 bolt, 12 bolt, rear ends -- explanation?

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The quickie answer is that, for GM products, the number of bolts refers to the number of bolts that retain the ring gear to the carrier inside the rear end. However, some clever GM Engineer also designed the cover bolt pattern to contain the same number of bolts...a 10 bolt ring gear has a 10 bolt cover, etc. There is no 8 bolt ring gear in a GM car or truck. There is, however, a 14 bolt rear end in later model 3/4 ton pickups.

The number of retaining bolts signifies the relative strength of the rear axle....more bolts indicates that the axle can transmit more torque. Ther are zillions of Chevy pickups running with 10 bolt rear ends...what is your intended use and engine size? A mild street truck is fine with a 10 bolt while a bigger pickup towing a heavy travel trailer may have problems.

Just like a "4 bolt main" block, the high-school mentality is that a 12 bolt axle is a must for a pickup......but do you always need a one? Let your intended use be your guide.

mike in tucson