Ford 9" Complete Positraction 3rd Member 3.90 Gear 31 Spline Posi Differential

Brand: Speedmaster

Product Code: SPE215-2051

Availability:In stock

$1,499.99 1,499.99


This 3rd member set includes an aluminum case that is made from A356-T6 aluminum, bearing caps are one-piece billet, with a through bolt design and extra material is added to the bearing caps.

The Torque Worm is a torque biasing 6 pinion gear type limited slip carrier. This unit is preloaded allowing for a faster reaction. Torque Worm design uses 6 pinion gears verses 3-4 pinion gears that competitors offer which means less stress on each gear and the load is spread over a greater surface area reducing wear on all internal components. Internal components are made of EN36 material and the outer case is made from 8620 Chrome-Nickel-Moly steel and case hardened for improved strength. Also available in 28 and 35 spline count.

The ring and pinion is a 3.90 ratio and made of HI-PERFORMANCE 8620 Chrome-Nickel-Moly Steel. CNC machined from high quality forgings to our exacting specifications and then heat treated to obtain high impact and durability. Then lapped to allow for correct tooth contact and smoothness and for use in the performance market. 3.00:1, 3.25:1, 3.50:1, 3.70:1, 3.90:1, 4.11:1, 4.56:1, 4.88:1 and 5.14:1 gear ratio's also available.

The yoke is a 1350 and is made of Billet and are a long style unit fully CNC machined to our specifications. Differential Yokes are available in sizes of 1310, 1330 and 1350.

These kits are rated at 850hp but are limited to 700hp due to factory 31 spline axles.