The GM rear end part number 3856525 is a 12-bolt rear axle assembly that was used in various GM vehicles from the 1960s to the 1980s. It is a semi-floating axle, which means that the axle shafts are not rigidly attached to the differential. This allows the axle shafts to move independently of the differential, which can help to reduce stress on the drivetrain. The 12-bolt rear axle assembly is also known for its strength and durability, which makes it a popular choice for high-performance applications.
The 12-bolt rear axle assembly was offered with a variety of different gear ratios, from 3.08:1 to 4.56:1. It was also available with a variety of different axle shaft sizes, from 28-spline to 35-spline.
The 12-bolt rear axle assembly is no longer in production, but it is still available from a variety of aftermarket sources.
