2007 STI Transmission | Subaru WRX STI 6-Speed Manual TY856

Description

About the 2007 STI Transmission (WRX STI 6-Speed Manual, TY856WB1CA)

Need a replacement Subaru WRX STI 6-speed manual transmission? Part Nests sources OEM used STI 6-speed transaxles for Subaru WRX STI applications. The Subaru WRX STI is Subaru’s iconic performance-oriented compact sport sedan / hatch application – Subaru’s top-tier WRX-derivative performance variant with distinctive Subaru WRX / STI enthusiast culture and heritage. The STI 6-speed manual transaxle (part number TY856WB1CA) is Subaru’s dedicated 6-speed manual transaxle for STI applications – includes integrated front differential and DCCD (Driver Controlled Center Differential) center differential providing all-wheel-drive torque distribution control. Two distinct chassis contexts covered by this listing per the source data – GD chassis (2004-2007 seventh-generation Impreza / early WRX STI production) and GR / GV chassis (2008-2014 eighth-generation Impreza / mid-era WRX STI production). Both chassis use the EJ25 2.5L turbo boxer engine – Subaru’s iconic EJ25 turbo engine architecture used across various WRX STI applications during the era. CRITICAL final drive and DCCD verification per the source data – final drive gear ratio and DCCD type must match your rear differential and DCCD type. Different specific STI applications may have different specific final drive ratios and DCCD configurations – mismatched final drive between transaxle and rear differential will cause severe drivetrain damage. CRITICAL clutch type distinction per the source data – pull vs push type varies by year. Different STI production years use different specific clutch actuation configurations – verify clutch type for your specific application. Related to broader Subaru performance context. Not included: clutch kit, flywheel, axles, rear differential, fluid, and any DCCD controller or wiring unless confirmed. Professional installation recommended for correct final drive matching, clutch type verification, and DCCD setup. Each transaxle is function tested with gear engagement verified. Call (855) 634-4447 to verify STI chassis (GD 2004-2007 or GR/GV 2008-2014), final drive, DCCD type, and clutch type by VIN before ordering.

Chassis, Final Drive, and DCCD Verification

What Is Included and Not Included

Subaru WRX STI Vehicle Context (GD and GR/GV Chassis)

• Subaru WRX STI iconic performance variant: The Subaru WRX STI is Subaru’s iconic performance-oriented compact sport sedan / hatch application – Subaru’s top-tier WRX-derivative performance variant. Represents Subaru’s approach to premium performance compact sport applications with distinctive Subaru symmetrical all-wheel-drive architecture, EJ25 turbo boxer engine, and rally-heritage sport positioning. Distinctive WRX / STI enthusiast culture and racing heritage
• GD chassis (2004-2007): Per the source data compatibility, GD (2004 to 2007); confirm by VIN. The GD chassis is the seventh-generation Impreza chassis (produced 2001-2007). The 2004-2007 US-market WRX STI applications on the GD chassis represent the early era of US-market WRX STI production – the first US-market STI variants providing Subaru’s rally-heritage performance to the US market
• GR / GV chassis (2008-2014): Per the source data compatibility, GR/GV (2008 to 2014); confirm by VIN. The GR chassis (hatchback body style) and GV chassis (sedan body style) are the eighth-generation Impreza chassis (produced 2008-2014). Approximately 7-year production window during the late-2000s through early-2010s era for WRX STI applications on the GR / GV chassis
• EJ25 turbo boxer engine: Per the source data compatibility, EJ25 turbo (both chassis). Both GD and GR / GV WRX STI applications use the EJ25 2.5L turbo boxer engine – Subaru’s iconic EJ25 turbo engine architecture. Distinctive Subaru boxer engine configuration with turbocharged induction for STI performance applications
• WRX STI competitive positioning: Positioned to compete with Mitsubishi Lancer Evolution (during the era), Volkswagen Golf R, Ford Focus RS, Honda Civic Type R, and various other premium performance-oriented compact sport competitors during the era. Distinctive Subaru rally-heritage positioning

TY856WB1CA Transaxle Function, Final Drive, and DCCD Context

• TY856WB1CA transaxle function: The TY856WB1CA is Subaru’s dedicated 6-speed manual transaxle for STI applications. Integrated transaxle configuration combining 6-speed manual transmission, front differential, and DCCD center differential in a single unit. Standard Subaru symmetrical AWD transaxle architecture
• 6-speed manual gearbox: The transaxle includes 6-speed manual gearbox providing 6 forward gears plus reverse. Distinct from the 5-speed manual transmissions used in mainstream (non-STI) WRX applications during the era – the 6-speed manual is STI-exclusive configuration providing wider gear ratio spread appropriate for STI performance applications
• Integrated front differential: Per the source data included, the STI 6-speed transaxle with its integrated front differential. Standard Subaru transaxle architecture with front differential integrated in the transaxle unit. Provides torque distribution to front axle within the transaxle housing
• DCCD center differential: Per the source data included, the STI 6-speed transaxle with its integrated DCCD center differential. DCCD (Driver Controlled Center Differential) is Subaru’s dedicated STI center differential providing driver-adjustable torque distribution between front and rear axles. Distinctive Subaru STI feature providing enhanced AWD torque distribution control
• CRITICAL final drive matching: Per the source data final drive and DCCD, must match your rear diff and DCCD type. Critical drivetrain verification – final drive gear ratio in the transaxle must match the final drive gear ratio in the rear differential for correct AWD operation. Mismatched final drive between transaxle and rear differential will cause severe drivetrain damage due to differential AWD torque delivery. Verify final drive at order
• CRITICAL DCCD type matching: Per the source data final drive and DCCD, must match your rear diff and DCCD type. DCCD type (specific DCCD configuration) must match your DCCD type for correct DCCD operation. Different specific STI applications may have different specific DCCD configurations. Verify DCCD type at order
• CRITICAL clutch type distinction: Per the source data clutch type, pull versus push type varies by year. Two clutch actuation configurations – pull type clutch (clutch release mechanism pulls the throwout bearing) vs push type clutch (clutch release mechanism pushes the throwout bearing). Different STI production years use different clutch type configurations. Do NOT cross-fit pull and push type clutches – different actuation mechanism
• Not included items: Per the source data, clutch kit, flywheel, axles, rear differential, fluid, and any DCCD controller or wiring are not included unless specifically confirmed in writing. Standard scope – the STI 6-speed transaxle (TY856WB1CA) with integrated front differential and DCCD center differential is provided. Additional items (clutch kit matching your clutch type, flywheel, axles, rear differential matching your final drive, transmission fluid, DCCD controller and wiring) are separate items
• Professional installation: Per the source data tools note, professional installation recommended. Match the final drive to the rear differential, confirm the clutch type, and set up the DCCD. Critical installation requirement – STI 6-speed transaxle installation requires professional installer with final drive matching capability, clutch type verification, and DCCD setup capability

Related Subaru / Related Performance Transmission Listings

• Various Subaru / WRX / STI / performance transaxle replacement components available across our Part Nests catalog

Transaxle Specifications

• Type: OEM used Subaru STI 6-speed manual transaxle (TY856WB1CA) with integrated front differential and DCCD center differential
• Function: STI 6-speed transaxle provides manual transmission, front differential, and DCCD center differential functions in a single integrated unit
• Configuration: GD (2004-2007) or GR/GV (2008-2014) chassis; EJ25 turbo engine; specific final drive and DCCD configurations – verify by VIN
• What is not included: Clutch kit, flywheel, axles, rear differential, fluid, and any DCCD controller or wiring, unless confirmed in writing per the source data
• Tools required: Professional installation recommended (match final drive to rear differential, confirm clutch type, set up DCCD) per the source data
• Common failure modes: Synchro wear, gear wear, DCCD wear, various age-related component wear from performance applications
• Testing: Function tested, gear engagement verified, seal condition documented per unit before shipment

Vehicle Compatibility

Why Buy From Part Nests

• OEM verified STI 6-speed manual transaxle (TY856WB1CA) with integrated front differential and DCCD center differential
• Function tested, gear engagement verified, seal condition documented per unit
• Support for GD (2004-2007) vs GR/GV (2008-2014) chassis verification
• Support for CRITICAL final drive matching to rear differential
• Support for CRITICAL DCCD type matching
• Support for CRITICAL clutch type distinction (pull vs push varies by year)
• Support for EJ25 turbo boxer engine context
• Support for Subaru WRX STI rally-heritage performance context
• Related to broader Subaru / WRX / STI performance transaxle listings
• Free shipping to all 50 states
• 15 day replacement warranty on component defects
• Support team familiar with Subaru WRX STI GD and GR/GV chassis lineage and TY856WB1CA transaxle considerations
• Call (855) 634-4447 to confirm your STI chassis, final drive, DCCD type, and clutch type by VIN before ordering.