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Find Limited Slip Differentials for your Mustang

Ford Performance IRS Loaded Differential Housing; 3.55 (15-26 Mustang GT, V6, Dark Horse)Find parts that fit my vehicle

Item 406490
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15 Reviews | 10 Answers
Our Price

$1,230.51 each

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    Frequently Bought Together

      Product Information

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

      Features & Specs

      • Loaded Differential Housing For Mustang IRS
      • Iron Housing With Aluminum Cover
      • Includes 3.55:1 Ratio Gear Set And Traction-Lok Differential
      • Custom Calibration Required For Speedometer And Shift Corrections
      • Original Equipment On 2019 Mustang GT
      • Note On 2015-2017 Mustang Pinion Flange Change May Be Necessary Comes With Pinion Flange With 93mm Bolt Circle And 110mm Driveshaft Pilot Installed For Applications That Require 95mm Bolt Circle And 113mm Driveshaft Pilot Use FR3Z-4851-B Pinion Flange Available Through Ford Dealer
      • Fits 15-26 Mustang GT, V6, Dark Horse

      Description

      Premium IRS Assembly. The Ford Performance IRS Loaded Differential Housing; 3.55 is a direct replacement part designed to enhance the rear suspension and differential performance on specified Mustangs. It provides a fully assembled independent rear suspension with an optimized gear ratio, delivering improved traction and handling characteristics for both street and track applications.

      Construction and Appearance. This assembly features a durable iron housing paired with a lightweight aluminum cover to balance strength and weight savings. It includes a precisely manufactured 3.55:1 gear set along with a Traction-Lok limited-slip differential for superior traction and drivetrain responsiveness.

      Installation. Installation is straightforward for competent automotive technicians familiar with IRS systems, with no additional drilling required. Custom calibrations for speedometer accuracy and shift point adjustments are necessary to ensure optimal vehicle performance.

      Warranty. A factory warranty is available with this product to ensure long-term reliability and customer confidence.

      Application. Designed specifically to fit 2015 through 2026 Mustang GT, V6, and Dark Horse models, with particular note that pinion flange modifications may be required for 2015-2017 vehicles to match bolt circle and driveshaft pilot dimensions. This housing is original equipment on the 2019 Mustang GT.

      Ford Performance M-4001-88355B

      CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

      Installation & What's in the Box

      Installation Info

      Installation Time

      (approx) 6 Hours

      Difficulty Level:

      Mechanical expertise or professional installation required.

      Installation Guides

        No guide available for this part yet.

      What's in the Box

      • (1) Loaded Differential Housing, 3.55-Gear Ratio

      4.8

      Customer Reviews (15)

      Questions & Answers (10)

      Will It Fit My Mustang

      • Bullitt - 19, 20
      • Dark Horse - 24, 25, 26
      • GT - 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26
      • Mach 1 - 21, 22, 23
      • V6 - 15, 16, 17