Complete Ford 9 Inch Helical Posi Rear End, 31 Spline Axles, 58"

Our helical style limited-slip differential works with any factory Ford 9 inch differential case, gear, axles and bearings. The helical-gear design gives quiet operation, with no clicking when disengaging for corners. While under normal conditions the helical-gear style performs like an open differential, when required the differential automatically transfers torque to the wheel with the highest traction. Smooth power transfer is unnoticed by the driver.

When you want the traction benefits of a limited slip differential in your Ford 9 inch rearend without the expense and noise of a full-locker unit, our helical style differentials are just the ticket.

We run what we sell. Our third member units are the go-to choice for our own rides and we have built these units to last with high quality hardware and components. Tapered steel roller bearings minimize friction, better handle thrust loads and increase load carrying capacity. The ring gears are assembled with Grade 9 bolts with a tensile strength of 180,000 psi, a 15% increase over Grade 8 hardware. Heavy duty Grade 8 carrier cap bolts, a lock-style pinion nut with pre-applied Loctite and high-quality grade 5 pinion support bolts make our third member near-bulletproof.

Units include a Viton® pinion seal providing long lasting oil and chemical resistance. This seal retains elasticity up to 399°F (204°C) and intermittently up to 600°F (316°C) This high temp seal helps eliminate pinion leaks, reduces maintenance and keeps the third member properly lubricated. A carrier-to-housing gasket is available separately.

Our hand-assembled Ford 9 inch third member assemblies are made-to-order. We keep a supply of the most popular gears in stock, with most units built within 2-3 days. Our third-member units are shipped in a durable, reusable poly storage case, perfect for keeping multiple gear sets stored and ready for the track.

Features

• Hand-assembled by our trained technicians for an unbeatable combination of quality and value
• Track-tested durability in our own cars - we race what we sell
• Precision assembly for the correct backlash, preload, and proper amount of pinion shims to ensure the correct pattern on the ring gear teeth
• Ring and pinion gears of 8620 cold-rolled steel for long wear
• Nodular iron housing is stronger than OEM “gray" iron and has 4 lbs of additional reinforcement
• Large bearing “Daytona" style pinion bearing supports for strength and reliability
• Spacer and shim setup maintains critical pinion depth settings and easier to service than traditional crush sleeves
• Helical gear differential gives positive traction without the noise of a full locker
• Ring gears assembled with Grade 9 hardware, 15% stronger in tensile strength than Grade 8
• Viton® pinion seal, resistant to chemicals and high temperatures
• Grade 8 Carrier cap bolts
• Lock-style pinion nut with pre-applied Loctite®
• Grade 5 pinion support bolts
• Includes form fitted, reusable red poly storage case
• Choose gear ratio - 3.25, 3.50, 3.70, 3.89, 4.11, or 4.56