Whiteline Rear Differential Mount Front Bushing Kit – 2002-2007 Subaru WRX / 2004-2007 STI / 1993-2007 Impreza

Whiteline Rear Differential Mount Front Bushing Kit – 2002-2007 Subaru WRX / STI

Lock Down the GD WRX and STI Rear Differential
The rear differential on the 2002-2007 Subaru WRX and STI is mounted to the subframe with rubber bushings that allow compliance under the torque loads of AWD acceleration and braking. That compliance allows the diff to shift position under power, contributing to vague throttle-on response and reduced traction off corners. Whiteline’s polyurethane rear differential mount front bushing significantly reduces this movement, improving torque application consistency and rear traction.

DETAILS

• Rear differential mount front bushing kit for 2002-2007 Subaru WRX and STI (GD chassis)
• Polyurethane compound reduces diff mount compliance under torque loads
• Improves traction consistency and throttle response from the rear differential
• Drop-in replacement for the factory rubber bushing
• No chassis modifications required

Why Differential Mount Compliance Matters on AWD Cars
On a symmetrical AWD system like the GD WRX and STI, the differential is a central component in how power is distributed and how the car responds to throttle inputs. When the diff mount compliance allows the diff to rotate and shift under acceleration, the effective torque application to each axle changes in an unintended way. Firmer mounts keep the differential in its designed position, delivering more consistent torque distribution and a more connected feel off throttle-on.

Front Mount — Key Position
The front mounting point of the rear differential carries the highest share of the anti-rotation load under acceleration. This is the bushing position where compliance has the greatest effect on feel and performance — which is why Whiteline targets it specifically.

Part of the GD Drivetrain Bushing System
Whiteline covers multiple differential and transmission mount positions on the GD chassis. The rear diff front mount bushing works best as part of a comprehensive drivetrain mount refresh — front transmission mount, rear diff front and rear mounts together.

Why Choose Whiteline

Whiteline has been engineering suspension components from their facility in Australia since 1979. Every product in their catalog is developed with a clear goal: measurable improvement in handling, stability, and tyre contact. Whiteline’s polyurethane bushings, sway bars, control arms, and alignment correction kits are engineered using finite element analysis and validated on track before they reach the market. Their components are direct-fit, bolt-on solutions designed for enthusiasts who want real performance gains without fabrication or custom work.

The RallySport Take

Commonly underestimated as a performance modification but consistently well-received on the GD WRX and STI. The improvement in rear traction consistency and throttle response feel is real and immediately noticeable. Budget an afternoon for the job — bushing replacement is not complicated but does require the correct press tools and clean installation technique. Apply grease to all polyurethane-to-metal interfaces and assemble at ride height for correct bushing set. The improvement in chassis feel is immediate and the polyurethane will outlast whatever rubber is in there now.

What’s in the Box

• Rear differential mount front bushing kit for 2002-2007 Subaru WRX and STI (GD chassis)
• Polyurethane compound reduces diff mount compliance under torque loads
• Improves traction consistency and throttle response from the rear differential
• Drop-in replacement for the factory rubber bushing
• No chassis modifications required

Fitment