KellTrac Mustang Differential Bushing Upgrade Kit, Rubber (KTI-BUK15RD) - 2015–2026 Mustang
The KellTrac Rubber Differential Bushing Upgrade Kit is engineered for Mustang owners who want maximum strength, control, and longevity without the noise and harshness of solid or poorly designed aftermarket solutions. Designed as a full stock replacement, this kit eliminates the failure-prone weaknesses of factory and inferior aftermarket differential bushings while maintaining excellent drivability.
Featuring a proprietary rubber and billet bushing design, this system delivers controlled differential movement with the lowest NVH of any full replacement kit on the market. High-quality 12.9-grade fasteners sourced from Italy provide exceptional strength and clamping force, ensuring the differential stays securely mounted under hard launches, aggressive driving, and sustained track use.
Engineered to press into the factory IRS subframe just like stock, this kit installs cleanly without cutting, welding, or fabrication. Backed by a lifetime warranty, it’s the ideal solution for high-performance street cars, drag racers, and track builds that demand durability without compromise.
Features
- Full replacement rubber differential bushing kit for S550 and S650 Mustangs
- Proprietary rubber and billet bushing design for controlled movement
- Lowest NVH of any full differential bushing replacement kit
- 25% more clamping force than the next strongest offering
- ASTM A574 high-strength hardware with 170,000 PSI tensile strength
- Italian-sourced 12.9-grade alloy steel bolts
- High-strength Class 12 nuts with HSS standard and locking washers
- Press-in design installs like factory with no fabrication required
- Lifetime warranty
Important Notes
- Requires removal of the IRS subframe assembly for installation
- Front bolts torque to 159 ft-lbs; rear bolts torque to 129 ft-lbs
- Recommended to use a small amount of blue threadlocker on all fasteners
- Bushings press outside-in with billet faces contacting the differential mounting ears
- Long bolts install in the front mounts; shorter bolts install in the rear mounts
- Ensure arrows on front flange bushings face left-to-right during installation
- Minor shimming or differential position adjustment may be required due to factory tolerances
Fitment
- 2015 Ford Mustang
- 2016 Ford Mustang
- 2017 Ford Mustang
- 2018 Ford Mustang
- 2019 Ford Mustang
- 2020 Ford Mustang
- 2021 Ford Mustang
- 2022 Ford Mustang
- 2023 Ford Mustang
- 2024 Ford Mustang
- 2025 Ford Mustang
- 2026 Ford Mustang
Kelltrac Terms Of Service
Kelly considers his Kelltrac line to be a specialty line for a unique customer base and has his own terms of service in addition to Beefcake Racing's. You must accept these terms on all Kelltrac orders. Please read shipping times, cancellation, and returns. If time is of the essence, we do have other options that can ship right away / quicker. Just reach out to one of our sales associates at Beefcake Racing.
Cancellations & Returns
KellTrac Innovations does not accept product returns. Once your order ships, you own it and we will not accept it back - NO EXCEPTIONS. We do not accept order cancellations after the product has shipped. If you understand and accept this please check the box and continue checking out. If you do not accept this, please stop and discontinue the order process. Thanks!
Due to the custom nature of our business and product offerings, we charge a 20% order cancellation fee, period, non-negotiable, no matter who you are. Orders can only be cancelled before the product ships. We do not accept order cancellations after the product has shipped. If you understand and accept this please check the box and continue checking out. If you do not accept this, please stop and discontinue the order process. Thanks!
Leadtime
Please be aware that most orders ship within 2-4 weeks. In some (rare) cases, orders can take up to 6-8 weeks to ship. Holidays can severely impact these lead times. *DO NOT CONTACT US ABOUT YOUR ORDER UNLESS IT IS OLDER THAN 20 BUSINESS DAYS!* If you understand and accept this please check the box and continue checking out. If you do not accept this, please stop and discontinue the order process. Thanks!
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