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Yukon Gear 8.8-Inch Duragrip Posi Rear Differential with 5-Lug Axles; 31 Spline (99-04 Mustang GT, Mach 1)

Item 408367
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Market Price $1,081.99 You Save 15% ($157.10)
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$924.89 (kit)

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      Product Information

      Features, Description, Reviews, Q&A, Specs & Installation


      • Put the Power to the Pavement
      • 8.8-Inch Limited Slip Differential
      • Heavy-Duty Nodular Case
      • Forged 4320 Internals
      • Yukon 31 Spline 5 Lug Axles Included
      • Fits 1999-2004 GT, Bullitt and Mach 1 Mustangs with an 8.8-Inch Differential Housing


      Put the Power to the Pavement. Boost the performance and improve the road handling of your New Edge Mustang by upgrading to a Yukon DuraGrip Posi Rear Differential. This kit includes an 8.8-inch 31 Spline DuraGrip Posi Differential, a pair of 31 spline 5 Lug Axles and all the bearings and shims required for installation. This Yukon kit is ideal for those GT, Bullitt and Mach 1 owners who are looking to upgrade their stock differential and axles for better traction and more impressive burnouts.

      Posi Rear Differential. The DuraGrip Posi Rear Differential features a case constructed from a heavy-duty nodular iron and boast forged 4320 steel internals and composite clutches for dependable, heavy-duty performance and long life.

      31 Spline 5 Lug Axles. Stronger than OEM, Yukon Gear manufactures its 31 spline 5-lug axles from high-quality 1541H alloy steel for superior strength. They use a rolled spline process that produces an axle spline that is up to 30% stronger than standard cut splines.

      Durable Alloys. The parts in this Yukon Gear and Axle kit are built from high-quality, heat-treated metal alloys for long-term durability. Top quality ensures extended use before needing to replace the parts. This complete axle kit includes everything you need for optimal road handling.

      Application. This Yukon Gear 8.8-inch DuraGrip Posi Rear Differential Upgrade Kit with 31 Spline 5 Lug Axles is designed for 1999-2004 GT, Bullitt and Mach 1 Mustangs equipped with a 8.8-inch rear differential housing.

      Technical Note. 1986-2004 V8 Mustangs came factory equipped with 28 spline axles, except for 2003-2004 SVT Cobras which were 31 spline. You will need to reuse your factory 8.8-inch gear set, or upgrade to a set of our 8.8-inch rear gears required for this Limited Slip Differential. No aftermarket gears are included. For normal driving conditions we recommend you use 75W 90 rear gear oil. This will give you the same oil weight as factory. For colder temps or race use try 75w 140.



      Yukon Gear YA FMUST-4-31

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) 8.8-Inch Limited Slip Differential
      • (2) 31 Spline 5 Lug Axles
      • Carrier Bearings
      • Carrier Shims
      • Axle Bearings
      • Seals
      • Studs

      Customer Reviews (22)

        Questions & Answers

        10 More Questions

        Will It Fit My Mustang

        • Bullitt - 01
        • GT - 99, 00, 01, 02, 03, 04
        • Mach 1 - 03, 04