Ford Racing M-4033-G4 Super 8.8" IRS Differential Cover for 15-26 Mustang

Vehicle Fitment

2015-2026 Ford Mustang (with Super 8.8" IRS axle)

Fitment Notes

• Fits Super 8.8" Independent Rear Suspension (IRS) axle only
• Does NOT fit solid rear axle Mustangs
• Fits all 2015-2026 Mustang models including EcoBoost, GT, and Shelby GT350/GT350R
• Replaces factory rear differential cover
• Professional installation recommended

Features

• Lightweight 356-T6 aircraft-grade aluminum casting
• Load bolts provide additional support for differential bearing caps
• Prevents side-to-side bearing cap deflection under hard use
• Increased ring and pinion gear life
• Superior heat dissipation compared to factory cover
• 1/2"-14 NPT bosses for differential oil cooler applications
• Plugs included for cooler port bosses
• Machined "Ford" and "Ford Performance" logos
• Sealant and thread-locker included
• Complete installation instructions included
• Proudly manufactured in the USA

Specifications

• Brand: Ford Performance
• Part Number: M-4033-G4
• Differential Type: Super 8.8" IRS
• Cover Material: 356-T6 Aircraft-Grade Aluminum
• Cover Bolts: 10
• Ring Gear Bolts: 10
• Cooler Port Size: 1/2"-14 NPT (2 ports)
• Finish: Natural Aluminum
• Package Dimensions: 11.5" x 3.5" x 16.5"
• Package Weight: 11.45 lbs
• Country of Origin: United States
• UPC: 756122014189

Included Components

• (1) 356-T6 aluminum differential girdle cover
• (2) 1/2"-14 NPT pipe plugs
• Thread-locker
• Sealant
• Installation instructions

Product Description

The Ford Performance M-4033-G4 Differential Girdle Cover Kit is an essential upgrade for 2015-2024 Mustang owners looking to strengthen their Super 8.8" IRS rear axle assembly. This lightweight 356-T6 aircraft-grade aluminum cover replaces the factory rear differential cover and adds critical load bolts that provide supplemental support for the differential bearing caps. By preventing side-to-side bearing cap deflection during aggressive driving, drag racing, or track use, this girdle design significantly extends ring and pinion gear life. The aluminum construction dissipates heat faster than the factory cover, helping maintain optimal differential operating temperatures during sustained high-performance use. Two 1/2"-14 NPT bosses are machined into the cover for easy installation of a differential oil cooler system, with plugs included when a cooler is not used. The cover features machined Ford and Ford Performance logos for an authentic factory appearance. Complete with sealant, thread-locker, and detailed installation instructions. Proudly manufactured in the USA by Ford Performance.