Ford Performance

Ford Performance Mustang Traction-Lok Loaded Differential Housing 3.55 (2015-2023)

( saved $155.05 )

In Stock - Less than 5 available

Typically ships in 1-3 business days.

161 M-4001-88355B

Ford Racing has really stepped up to the plate with the new 2015+ Ford Mustang. This new mustang has come equipped with some great upgrades to really push this new S550 platform to its performance limits. One of those components is the Ford Racing S550 Mustang IRS Loaded Differential Housing 3.55.

Ford Racing S550 Mustang IRS Loaded Differential Housing 3.55 is the original equipment on the 2018+ Ford Mustang GT . This differential housing comes loaded with 3.55:1 ratio gear set (161-M-4209-88355A) and Traction-Lok differential (161-M-4204-M).

When used 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.

Note: Custom calibration is required for speedometer and shift corrections.

Purchase your Ford Racing S550 Mustang IRS Loaded Differential Housing 3.55 for your 2015+ Ford Mustang GT, EcoBoost, or V6 at Steeda Autosports today!

Product Benefits
  • Original equipment on 2019+ Mustang GT
  • Iron housing with aluminum cover for strength
  • Fits 34-spline axles
  • Made in the USA
  • Ford Racing quality

warningWARNING: California Residents: Cancer and Reproductive Harm;

Installation Difficulty:
Tools Required:
Basic Shop Tools
Estimated Install Time:
(approx.) 7 Hours
Vehicle Fitment:
2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023
  • Free Ground Shipping

  • Enthusiast-Driven Customer Service

  • Over 35 Years in Business