Components for the pinion gear installation include the pinion gear (3 series shown), 1310 yoke, crush sleeve, Timken tapered pinion bearings, oil seal, shims (amounts may vary based on desired setup), and lock down washers and nut.
Two different style yokes are available for the 12-bolt housing application. The yoke on the left is a 1350 series yoke designed primarily for racing applications, while the yoke on the right is a 1310 series utilized primarily for stock GM OEM rears.
Once the pinion is installed, installation of the carrier bearings follows. The posi unit shown is an Eaton 30-spline TruTrac unit. The carrier bearings must be pressed on completely.
To speed up the process and make the securing of the ring gear to the carrier easier, Chad has preheated the ring gear to 300 degrees Fahrenheit and is bolting the gear in place.
Moser Engineering manufactures the only ABS compatible aftermarket 12-bolt rearend. Shown is the Moser Engineering designed exciter ring, otherwise known as a reluctor ring, and an Eaton posi unit.
With the shims in place, bearings pressed on, ring gear bolted down, and the pinion gear set, the limited slip is placed inside the center section of the housing unit by way of a case spreader.
Following the installation of the carrier and the mounting of the main caps, Chad applies a marking compound to check the gear pattern.
This picture shows the optimal gear pattern. The pinion depth and pattern are set depending on the gear manufacturer's recommendation on each particular set of gears.
Once the pattern is set, the gear backlash is set. Backlash is the amount of space between the gears. For the Moser Engineering 12-bolt units, the optimal backlash setting is dependent on each customer's specific application. The particular application shown asks for a backlash of .008.