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Alloy USA 8.8 Axles - 31 Spline 5 Lug (99-04 GT, Mach 1)

8 Reviews
Our Price

$289.99

  • Item #18957
  • MPN #12187
  • Market Price $324.79
  • You Save 11% ($34.80)
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Customer Photos
Features
  • 1541H alloy steel
  • 31 spline
  • 5 x 4.5" - five lug design
  • 10 Year warranty!
  • Driver and passenger side axles included
  • Fits 1999-2004 GT, Bullitt and Mach 1 Mustangs with 8.8" rears
Description
Performance Upgrade. If your Mustang is heavily modded or running a forced induction setup, your stock factory 28 spline axles might be too weak to take the heat. These premium quality 1541H alloy steel axles have 31 splines to ensure all that power and torque is transferred straight to the pavement - where it belongs. Stronger than OEM. Manufactured from high quality 1541H alloy steel using a computer controlled induction heat treatment that results in a stronger, more durable axle shaft. Alloy USA uses a cold-formed rolled spline process that produces an axle spline that is up to 35% stronger than standard cut splines.

10 Year Warranty. These Alloy USA axles come with a 10 year limited warranty to be free of defects in material and workmanship from the date of purchase. Some limitations do apply. Please see the full Alloy USA Warranty disclosure for details.

Application. This pair of Alloy USA 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: 1986-2004 V8 Mustangs came factory equipped with 28 spline axles, except for 2003-2004 SVT Cobras which were 31 spline. All 2005 and newer V8 Mustangs come equipped with 31 spline axles.

Mustang Fitment: 1999 2000 2001 2002 2003 2004 Details

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: Press in
Fitment
  • Bullitt - 01
  • Mach 1 - 03, 04
  • GT - 99, 00, 01, 02, 03, 04

Fits 8.8" rear gears with 31 spline LSD or Spool only

Most Helpful Reviews View All

Overall Rating 4.9/5 Write a Review
5/5
Rear end 2fast 2furious Saleen, movie car)

When I bought this car it had been raced hard and the rear was toast. I upgraded to the 31 spline axles, ford diff,ford racing aluminum driveshaft and ford racing diff cover. The car is quieter and smooth

Read More
Helpful (1) (0)

5/5
Excellent product

I bought this with Ford Racing 4.10 gears and the posi trac differential. I Also purchased a 75mm throttle body and a bama tuner. I am 100% satisfied with everything I bought and installed. Great products,

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Helpful (1) (0)

Customer Photos (6) View All

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Q & A (1 Questions, 2 Answers) Ask a Question

What should I stall with this axles? I have a stock 2000 Mustang GT, and I would like to know what other parts should I install to fit this axles to my Mustang. Should I install also another Driveshaft and Differential? I would like this part for track usage and daily drive, and I will make some power mods to the car. Thanks in advance!

PedroSalomao Year: 2000 Model: GT

Good Question (0) (0)
  • You will need a 31spine carrier unit for these to fit a 2000 GT which had a 28 spline carrier from the factory.

    Helpful (0) (0)

    Runningstang2004 Year: 2004 Model: GT

Show 1 more answer Answer This Question

Reviews (8) Write a Review

  • 5 Stars .88 88%
  • 4 Stars .12 12%
  • 3 Stars 0 0%
  • 2 Stars 0 0%
  • 1 Stars 0 0%
4.9

out of 5 stars

8 Customers Recommend this Product

Filter By Sort By
  • 5/5

    Must have

    October 17, 2014

    While putting in new 3.73 gears wanted to upgrade my limited slip differential, the Gt differential is a 28 spline 8.8in for $484.99 ...upgrade to the 31 spline which was half the cost plus these bad boys made it the same price as the diff alone plus my rear end is ready for anything I can throw at it. Thanks AM.

    Danwago

    Year: 2003 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 1 San Antonio, TX, USA

    Helpful (1) (0)

  • 4/5

    Great product

    October 17, 2014

    This is a great quality set of axles... One of the only companies to offer a 10 year warranty. The only single complaint I have is they come with the cheaper koyo bearings... I expected them to use something made in USA but they are still great quality bearings don't let that keep you from buying them. One thing I did notice is these axles seem to be wider than stock... Maybe it's just me but had to grind a very slight amount off of the passenger side caliper bracket. I'm talking very slight. Wasn't worth the hassle of a return to me. Handles my 410hp gt without a problem

    Dandaman779

    Year: 2002 Model: GT Driving Style: Street / Strip 'Stangs I have owned: 3 Pa

    Helpful (1) (0)

  • 5/5

    Great Axles

    September 21, 2014

    Great axles, Nice upgrade to my stang. Easy to install.

    DBoi941

    Year: 2002 Model: GT Driving Style: Street / Strip 'Stangs I have owned: 1

    Helpful (1) (0)

  • 5/5

    Rear end

    October 23, 2013

    My car has 140k+ miles and I decided to install some 4:10 gears. Figured while I have it apart, I might as well replace everything the first time. Install went great and now my rear end is bullet proof.

    Drunkninja

    Year: 2000 Model: GT Driving Style: Street / Strip 'Stangs I have owned: 1 Hilton, NY 14468, USA

    Helpful (1) (0)

  • 5/5

    Excellent product

    October 19, 2013

    I bought this with Ford Racing 4.10 gears and the posi trac differential. I Also purchased a 75mm throttle body and a bama tuner. I am 100% satisfied with everything I bought and installed. Great products, everything I have is a must have for a mustang. Very aggressive off the line and excellent throttle response. Thanks American muscle!!!!! I have and will always buy from American Muscle.

    Perry52D

    Year: 2000 Model: GT Driving Style: Street / Strip 'Stangs I have owned: 2 Valparaiso, IN, USA

    Helpful (1) (0)

  • 5/5

    Great Product

    October 18, 2013

    These axles worked out great for my 31 spline up grade on my 04 gt.

    Runningstang2004

    Year: 2004 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 5+ Toledo, OH, USA

    Helpful (1) (0)

  • 5/5

    Rear end 2fast 2furious Saleen, movie car)

    July 01, 2013

    When I bought this car it had been raced hard and the rear was toast. I upgraded to the 31 spline axles, ford diff,ford racing aluminum driveshaft and ford racing diff cover. The car is quieter and smooth on all launches. So far I am very happy. Also picked the axles because they were made in the US.

    Vault

    Year: 2002 Model: GT Driving Style: Street / Strip 'Stangs I have owned: 3 Haddon Heights, NJ, USA

    Helpful (1) (0)

  • 5/5

    Fast shipping

    September 21, 2013

    Bought these to beef up the rear end of my turbo mustang. Kind of like an insurance policy when launching with slicks.

    Ohler248

    Year: 2001 Model: GT Driving Style: Street / Strip 'Stangs I have owned: 3 ROC NY

    Helpful (0) (0)

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