If you've ever felt your 350Z or 370Z hop and shudder on a hard launch, the differential mounting is often the culprit. The factory rubber differential bushings are a known weak point on the Z platform, tearing under hard driving and letting the differential shift around under load. The ISR Performance Differential Mount Bushings replace the worn factory rubber with solid bushings that lock the differential in place, reduce wheel hop, and put more of your power to the ground.
What It Is
The ISR Performance Differential Mount Bushings are a set of solid replacement bushings for the Nissan 350Z, 370Z, and Infiniti G35 differential mounting points. They replace the factory rubber differential bushings, which are prone to tearing and deflection under hard use. The ISR bushings are solid, which eliminates the compliance that lets the factory rubber bushings deflect and the differential move around under load.
What It Does
The factory differential bushings on the Z and G platforms are rubber, and they're a known failure point. Under hard launches, aggressive acceleration, and repeated load cycling, the rubber tears and deteriorates over time. Even before they fail outright, the rubber bushings allow the differential to shift and rock under load, which wastes energy in deflection instead of transferring it to the wheels.
The ISR solid bushings keep the differential from moving under hard launches or acceleration. This reduces wheel hop, which is the violent shudder you feel when the drivetrain loads and unloads rapidly on a hard launch, and it improves power transfer to the ground by eliminating the deflection in the mounting. The result is a more direct, planted feel from the rear end under power.
Why Solid Over Rubber
The factory rubber bushings prioritize noise, vibration, and harshness isolation, which is fine for a stock car driven gently. The tradeoff is that rubber deflects under load and tears under hard use, both of which are problems on a car driven the way Z and G owners tend to drive them.
Solid bushings remove the deflection entirely. The differential stays locked in position regardless of how hard you launch or how aggressively you get on the throttle. The tradeoff is that solid bushings transmit more drivetrain noise and vibration into the chassis than the factory rubber, which is the normal and expected result of a solid bushing upgrade. For a performance-driven car, that tradeoff is worth it. For a car that prioritizes maximum quietness and isolation, the factory rubber is the more comfortable choice.
Fitment and Compatibility
These differential mount bushings fit the following vehicles:
- 2003-2008 Nissan 350Z (Z33)
- 2009 and newer Nissan 370Z (Z34)
- 2003-2006 Infiniti G35 Sedan
- 2003-2007 Infiniti G35 Coupe (V35)
The bushings are a direct replacement for the factory differential bushings on these chassis.
Who This Is For
These bushings fit a few common build profiles. If you've got a 350Z, 370Z, or G35 that hops and shudders on hard launches, solid differential bushings are one of the most effective fixes for wheel hop on the platform. If your factory differential bushings have torn or deteriorated (a common issue on higher-mileage and hard-driven cars), this is the upgrade replacement rather than going back to factory rubber. If you're building a track, drag, or drift car where every bit of power transfer matters and you want the differential locked solidly in place, these eliminate the deflection that costs you on launch.
These are not the right choice if your car is a comfort-focused daily driver and you want to keep drivetrain noise and vibration to an absolute minimum. Solid bushings will transmit more NVH than the factory rubber.
Installation Notes
Professional installation is recommended. Differential bushing replacement requires lowering or removing the differential to access the mounting points and pressing the old bushings out and the new ones in. This typically requires a press and the ability to support the differential safely, which is beyond a basic driveway setup for most builders. Inspect the differential mounting points and surrounding hardware while the unit is accessible, since access is never easier than during this job.
Product Details
Brand: ISR Performance
Product: Differential Mount Bushings
Part Number: IS-Z33-DIFF
Vehicle Fitment: 2003-2008 Nissan 350Z (Z33), 2009+ Nissan 370Z (Z34), 2003-2006 Infiniti G35 Sedan, 2003-2007 Infiniti G35 Coupe (V35)
Type: Solid differential mount bushings
Replaces: Factory rubber differential bushings
Function: Locks differential in place, reduces wheel hop, improves power transfer
NVH Note: Solid bushings transmit more drivetrain noise and vibration than factory rubber
Installation: Direct replacement, press required
Key Benefits: Eliminates differential deflection under load, reduces wheel hop on hard launches, improves power transfer to the ground, solves the known factory rubber bushing tearing issue