Original Equipment on Manual GT.
When the light turns green, allow your V6 or GT S550 to accelerate off the line faster by installing a Ford Racing 3.55 Differential. This Ford Racing 3.55 IRS Differential Housing improves the low end torque of your Mustang for stronger, quicker launches. So whether you want to upgrade your gears or replace a broken housing, you can't go wrong with a direct fit replacement differential that was standard on manual GT Mustangs from the factory. This fact makes the manual iron differential the perfect upgrade replacement for automatic Mustangs that see a lot of track time.Pre-Loaded.
Ford Racing pre-installs a set of their 3.55 ratio gears and a LOK Limited Slip Differential into an iron IRS housing and tops it all off with an aluminum cover. This LSD is ready to be installed straight out of the box.Traction-LOK Limited Slip Differential.
The included heavy duty Ford Racing Traction-LOK Limited Slip Differential (LSD), sometimes referred to as a "Posi", allows both rear wheels to put the power down to the pavement as needed. If one of the drive wheels begins to slip or lose traction, the LSD transfers more power to the nonslipping wheel to provide better traction to keep you moving. This makes Limited-slip Differentials ideal for street, autocrossing, road racing and impressive burnouts.Ford Racing 3.55.1 Gears.
The pre-loaded Ford Racing ring and pinion gears have a 3.55:1 gear ratio and 8.8" ring gear diameter. These gears are manufactured in the USA and feature a super strong forged construction with CNC cut & lapped gear teeth. They are completed in a black oxide finish for corrosion resistance.Required Upgrade.
The Ford Racing 3.55 IRS Differential will require reprogramming the vehicles computer for speedometer and shift point corrections. AmericanMuscle recommends a Bama custom tune with a Mustang Handheld Tuner
to reprogram the vehicles computer (ECU) for proper operation.Automatic Transmission Requirement.
Installation of this Loaded IRS Differential Housing on a S550 Mustang with an automatic transmission will require the Automatic IRS Pinion Flange Kit part# M-4851-M8A for proper installation. Application.
This Ford Racing 3.55 Loaded IRS Differential Housing is a direct fit upgrade replacement for the 2015 to 2018 GT and V6 Mustangs. Designed for use with independent rear suspensions (IRS) and requires the use of 34 spline axles.