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SR Performance 8.8 Axles - 31 Spline 5 Lug (99-04 GT, Bullitt, Mach 1)

Item 525037
Market Price $296.99 You Save 12% ($35.90)
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    Features & Details

    • 1541H High Manganese Steel Alloy
    • 31 Spline Axle
    • 5 X 4.5" - Five Lug Design
    • 30.630" Axle Length
    • Kit Includes Driver and Passenger Side Axles
    • Bearings, Seals and Studs Also Included
    • Fits 1999-2004 GT, Bullitt and Mach 1 Mustangs with 8.8" Rears
    Performance Upgrade. If your running a heavily modified or forced induction New Edge Mustang, your factory 28-spline axles might be too weak to take the additional punishment. But after installing a set of SR Performance 31-spline 1541H alloy steel axles you will be sure to get all your pony's power and torque firmly planted to the pavement - where it belongs.

    Built to Out Perform. SR Performance Axles are forged from premium quality 1541H high manganese steel alloy that is induction heat treated for an axle shaft that is stronger and much more durable than stock, making it perfect for high stress street and race applications.

    Application. This pair of SR Performance 5-Lug 31 Spline Axles are specifically designed for use on 1999 to 2004 GT, Bullitt and Mach 1 Mustangs that have upgraded to a 8.8" 31-spline LSD or Spool only.

    Application Note: 1979-2004 V8 Mustangs came factory equipped with 28 spline axles, except for 2003-2004 SVT Cobras which were 31 spline.

    SR Performance

    Fitment: 1999 2000 2001 2002 2003 2004 Details

    MPN# 525037

    CA Residents: WARNING: Cancer and Reproductive Harm -

    What's in the Box
    • (2) 31 Spline Axles
    • (10) Wheel Studs
    • (2) Outer Axle Shaft Bearings
    • (2) Seals
    Installation Info
    Tech Specs
    • Splines: 31
    • Type: C-clip
    • Stud Pattern: 5 x 4.5"
    • Stud Type: 1/2" Press in
    • Length: 30.630 in
    • Material: 1541H alloy steel
    Will it fit my Mustang?

      Customer Photos

        Questions & Answers (3)

        3 Top Rated Questions

        What is the warranty on these axles

        • These have a 30 day warranty.

        Helpful (0)

        Do you have to shim the brake calipers out with these? I've heard of that issue with one of the other major axle brands for the same application.

        • No, the brake calipers will not need to be shimmed however you would need a new diff with 31 spline spider gears to install these.

        Helpful (0)

        Will the factory ABS tone rings fit on these SR axles? The Moser axles specifically state that they will, but the SR axles do not.

        • I'm pretty sure AM would state in their description that you'd need different ABS rings if that was the case. The only time I've seen AM not inform you about other parts needed it's been because they didn't know at the time. I'm sure they're fine. I'm buying them right now and I don't expect to have any trouble.

        Helpful (0)
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          Customer Reviews (8) Write a Review

          Overall Rating 5

          out of 5 stars

          Installation Time:Afternoon

          • Performance Gain 4.75 4.8
          • Fit 4.875 4.9

          • 5/5

            Installation Time: Less than 1 Hour

            September 02, 2019

            What an upgrade!

            Was upgrading my gears and carrier and thought why not replace the axles. These axles make a huge difference when driving. They put the power to the ground with great grip and acceleration. Highly recommend.


            Year: 1999 Submodel: GT

            Helpful (0)

          • 5/5

            Installation Time: Less than 1 Hour

            October 02, 2017

            31 spline axle

            I upgraded from my broken 28 spline to the sr 31 spline axles and I'm throughly impressed with quality and service.


            Year: 2002 Submodel: GT

            Helpful (10)

          • 5/5

            September 07, 2017


            was doing ring and pinion, bought everything to rebuild the whole rear end, these axles are better than stock.


            Year: 2000 Submodel: GT

            Helpful (12)

          • 5/5

            Installation Time: Afternoon

            August 29, 2017

            Buy these

            Fit as they should, bearings fit correctly, would buy again if i had to


            Year: 2003 Submodel: GT

            Helpful (10)

          • 5/5

            August 11, 2017


            Have not installed three yet need more stuff to complete project. And adding more as I go


            Year: 2001 Submodel: GT

            Helpful (11)

          • 5/5

            Installation Time: Afternoon

            March 11, 2016

            Sr. performance axles

            Perfect fitment great quality easy instaliton great choice switch from factory 28 spline glade i did


            Year: 2003 Submodel: GT

            Helpful (11)

          • 5/5

            Installation Time: Afternoon

            July 18, 2014

            Solid product

            Everything looks perfect until I have to take out the abs ring out, but other than that very good I have lots of traction on my wheels


            Year: 2003 Submodel: GT Miami, FL, USA

            Helpful (10)

          • 5/5

            Installation Time: Full Day

            June 20, 2014


            Upgraded my dif to 31 spline these axles haven't given me any problems and fit good


            Year: 2001 Submodel: Bullitt New Hampshire, USA

            Helpful (12)

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