GForce 9" IRS Kit (2015-2023 Mustang S550) FOR10904A

The GForce 9” conversions are designed to take over where the OEM differential begins to suffer from strength and reliability concerns. This can happen at various levels of power or abuse for different platforms. No driveline component will ever be “bomb-proof” in a racing environment, but the GForce 9” kit will give you the best chance of rear-end survival and reliability, all while retaining the factory style IRS.

Our 9” conversions use a Strange Engineering aluminum center section paired with the Strange S-Trac differential, which has proven to be a phenomenal combination to retain OEM-like drivability, while being able to support a tremendous amount of torque in a functional differential. We use a standard 9” 28-spline pinion “street” gear for the vast majority of applications, but we can also do 35-spline pinion Pro Gears upon request for customers who are interested in drag-only applications.

Most applications will be offered with a top-of-the-line 4” aluminum driveshaft that uses a Sonnax slip joint and tubing that we have tested to be about 13% stronger than the industry standard. This also comes with a direct bolt transmission flange, or forged slip yoke for traditional style open-tailshaft transmissions.

All rear ends will be offered with upgraded polyurethane differential bushings as standard with the option to upgrade to billet aluminum for higher torque and racing applications. We do not include, but STRONGLY encourage you to source your own upgraded polyurethane cradle bushings. The differential and cradle bushings are the two fundamental support pieces we focus on first when looking at rear end stability and they need to be upgraded accordingly as you go up in power. Together, they will not only help prevent wheel hop and control pinion rise, but they will also make the car more consistent and feel more controlled on the road and at the track.

GForce 9” Kits Include the following:

• Strange Pro HD center section with your choice of 9” gear
• GForce fabricated rear housing and front mount to adapt the 9” center section to the factory cradle
• Renegade Axles with option to upgrade to Outlaw Axles
• 35 Spline 9” inner stub assembly specific to our fabricated housing
• Outer splined stubs to suite the appropriate OEM spline count for a given application
• Hardware for install (some applications may reuse some factory mounting hardware)
• 4” Aluminum driveshaft to suite OEM style transmission

Options: 

- Poly Bushings (standard) or upgrade to Solid Aluminum Bushings (+$100)
- GForce Renegade Axles (standard) or upgrade to Outlaw Axles (+$400)

Note: Some vehicles will have very little clearance around the passenger side factory 2 pc driveshaft carrier bearing mount and it may require you to “massage”, cut back, or remove the factory mount entirely, depending on available clearance for driveshaft movement.

Fitment: 

GForce 9” Kits are designed to fit in the factory location and work with factory components with as little modification as possible. When installing a GForce 9” kit, it is up to the installer to check for clearance around all components, including potential clearance issues from drivetrain and suspension movement. Axle boots can sometimes be close enough to shocks or suspension that they could rub and cause a failure down the road. Most OEM shock mounts can be loosened and allow you to push the shock body away from the axle and gain a little more clearance to avoid any issues.

Modification might be necessary for driveshaft clearance, especially with exhaust, specifically towards the diff, where the pinion height will be at a lower level, compounded by using a larger diameter driveshaft. 9” kits are not guaranteed to fit with ANY other aftermarket products. Aftermarket shocks, control arms, etc. may present clearance issues. If CV boots have clearance issues, low profile boots can be purchased at an upgraded cost. The low profile boots reduce the amount of available axle angle in comparison to the standard boots, so they are not ideal for lowered or high axle angle vehicles. This includes 2010-15 Camaro and all years of Mopar platforms. If you have questions or would like to add low profile boots to your axles, please contact us for more information.

Dedicated race cars may require other considerations for gear and bushing choice; please call with questions.

Damage Prevention:

NO DRIVELINE COMPONENT IS BOMBPROOF! GForce does not put a power rating on any driveline components as there are entirely too many variables that can affect a driveline component outside of power. We take great pride in trying to build the strongest driveline components to fit within certain applications, but it is important to know that You, the end customer, are responsible for seeing to proper installation and You, as the driver, are responsible for the lifespan of your axles or other driveline components. 

Service:

All driveline components will fatigue or wear over time depending on how the vehicle is driven and what level of performance is demanded from them. CV joints are a wear item and will see wear over time, but with our current design, axles can be sent in for service. So boots, fasteners, and CV assemblies can be serviced without scrapping the complete axle assembly. It is up to each customer to establish their own maintenance intervals based upon the manner in which their car is driven. Individual inner or outer splined stubs and axle bars can be replaced as well if they twist or are damaged due to wheel hop or simply from power levels exceeding capability of the material.