SuperPro SPF4857-90K Rear Diff-to-Subframe Mount Bushings 90A Motorsport Toyota

Vehicle Fitment

• 1993-2002 Toyota Supra (JZA80, 2JZ-GTE, RWD)
• 1990-2000 Toyota Soarer (_Z3_, RWD)
• 1993-1996 Toyota Aristo (JZS147, RWD)
• 2006-2013 Lexus IS250 (XE20, RWD)
• 2006-2013 Lexus IS350 (XE20, RWD)
• 2008-2014 Lexus IS F (USE20, RWD)
• 2009+ Lexus IS C (GSE2_, RWD)
• 1993-2011 Lexus GS (S140 / S160 / S190 Chassis, RWD)
• 1989-2006 Lexus LS (XF10 / XF30 Chassis, RWD)
• 1991-2000 Lexus SC (Z30 Chassis, RWD)

Fitment Notes

• Fits the rear upper rearward differential-to-subframe mounting position - replaces the factory rubber differential mount bushings at this location
• RWD applications only - confirm chassis code and drivetrain before ordering
• Rear wheel alignment is required after installation
• 90A (Motorsport) durometer - this is the high-performance version; for a standard replacement with OEM-comparable NVH levels, use SPF4857K (80A)
• The 90A version is recommended for high-horsepower builds and track (circuit or drag racing) applications; some increase in NVH versus stock is expected at this durometer

Features

• 90A durometer polyurethane - significantly reduced deflection under load compared to both the OEM rubber mount and the 80A standard version; provides more positive differential location under hard acceleration, braking, and direction changes
• Reduces wheel hop and improves power transfer efficiency by minimising differential movement under load - particularly beneficial during drag launches and hard circuit corner exits
• SuperPro's proprietary elastomer-based engineering-grade polyurethane formula - designed to exhibit the best characteristics of both rubber (compliance, NVH) and plastic (rigidity, wear resistance) in a single compound
• Superior abrasion resistance and chemical resistance compared to OEM rubber - unaffected by oil, heat, ozone, and weather exposure that accelerate rubber degradation over time
• Does not require replacement intervals - designed to outlast the vehicle when installed and maintained correctly
• Engineered and manufactured by SuperPro in Brisbane, Australia - all SuperPro polyurethane products are designed, formulated, and produced in-house to exacting quality standards
• Covered under SuperPro's Lifetime Warranty for bushings (SPF-prefix parts) - warranty is valid for all uses including motorsport and track applications

Specifications

• Part Type: Rear Differential-to-Subframe Mount Bushing Kit - Motorsport
• Position: Rear upper (rearward)
• Durometer: 90A polyurethane
• Material: SuperPro proprietary engineering-grade polyurethane
• Standard Replacement Version: SPF4857K (80A)
• Alignment Required: Yes - rear wheel alignment required after installation
• Warranty: Lifetime (SuperPro bushing warranty, valid including motorsport use)
• Package Dimensions: 9.0 in. L x 6.0 in. W x 1.5 in. H
• UPC: 9317745768326

Included Components

• 2x 90A Polyurethane Differential Mount Bushings

Product Description

The SuperPro SPF4857-90K is the motorsport (90A) version of the rear differential-to-subframe mount bushing kit for a broad range of Toyota and Lexus RWD platforms, including the JZA80 Supra, Soarer, IS250/IS350/IS-F (XE20), GS, LS, and SC series. The factory rubber differential mount bushings allow measurable differential movement under load - under hard acceleration, the differential can deflect rearward within the subframe, absorbing power and slowing throttle response. The 90A polyurethane bushings in this kit significantly reduce that deflection, keeping the differential located more precisely under power for quicker, more consistent power delivery to the rear wheels.

The 90A durometer is the higher-stiffness of the two SuperPro options for this application. The 80A version (SPF4857K) offers a closer match to OEM NVH levels while still delivering improved performance over the stock rubber - it is the better choice for street-only daily drivers. The 90A version is specifically recommended for high-horsepower builds and vehicles that see regular track use, where the additional stiffness produces a measurable improvement in launch response and drivetrain alignment stability. A small increase in NVH versus the 80A is expected and is the trade-off for the tighter differential location. Rear wheel alignment is required after installation. Backed by SuperPro's Lifetime Warranty, which covers motorsport and track applications with no exclusions for performance use.