JDM 2013–2018 Subaru BRZ 31009JB000 / TX6A8GD90A FA20 2.0L 6-Speed Automatic RWD Transmission

Replace your slipping, delayed-engagement, harsh-shifting, noisy, damaged, or failed automatic transmission with this low-mileage JDM Subaru BRZ 6-speed automatic RWD transmission from J-Spec Auto Sports.

This OEM transmission targets compatible 2013–2018 Subaru BRZ models equipped with the FA20 2.0L naturally aspirated boxer engine and rear-wheel drive.

This individual inventory unit is Item ID 54940 and carries Subaru OEM part number 31009JB000. Subaru parts data identifies the transmission model associated with this assembly as TX6A8GD90A, with earlier assembly number 30098AA050 superseded by 31009JB000.

The primary drivetrain relationship is:

Subaru BRZ → 2013–2018 → FA20 2.0L → TX6A8GD90A / 31009JB000 → 6-Speed Automatic → RWD

Quick Details

• Make: Subaru
• Model: BRZ
• Model Years: 2013–2018
• Engine Code: FA20
• Engine Size: 2.0L
• Engine Configuration: Naturally Aspirated Boxer 4-Cylinder
• OEM Part Number: 31009JB000
• Transmission Model: TX6A8GD90A
• Transmission Type: Automatic
• Number of Gears: 6-Speed
• Drivetrain: Rear-Wheel Drive / RWD
• Transmission Fluid: Auto Fluid WS
• Condition: Used JDM / Low Mileage
• Origin: Japan
• Item ID: 54940
• SKU: MT651
• Actual Product Photos: Yes
• Warranty: 90 Days
• Shipping: Nationwide Freight Shipping
• Installation: Affordable Installation Available
• Local Pickup: Richmond / Henrico, Virginia

The live J-Spec listing confirms Item ID 54940, Product Code Subaru BRZ 6AT, 2013–2018 application, automatic transmission type, SKU MT651, actual inventory photos, and a 90-day warranty.

31009JB000 / TX6A8GD90A 6-SPEED AUTOMATIC TRANSMISSION

The Subaru BRZ automatic transmission assembly is identified by OEM part number:

31009JB000

Subaru parts data also associates the assembly with transmission model:

TX6A8GD90A.

This transmission uses:

• Six forward gears
• Torque-converter operation
• Electronic shift control
• Manual shift mode
• RWD output configuration
• Internal planetary gearsets
• Electronically controlled valve body

It is not a CVT.

FA20 2.0L BOXER ENGINE APPLICATION

This transmission targets compatible first-generation Subaru BRZ applications equipped with the FA20 2.0L naturally aspirated boxer engine.

The important drivetrain relationship is:

FA20 2.0L + 31009JB000 / TX6A8GD90A + 6AT + RWD

Engine family alone does not guarantee complete interchangeability. Always verify the original transmission identification and vehicle configuration.

VEHICLE COMPATIBILITY

2013 Subaru BRZ 2.0L Automatic

• FA20 2.0L
• 31009JB000-compatible assembly
• TX6A8GD90A
• 6-speed automatic
• RWD
• Verify original transmission identification

2014 Subaru BRZ 2.0L Automatic

• FA20
• 6AT
• RWD
• Verify VIN and production date

2015 Subaru BRZ 2.0L Automatic

• FA20 2.0L
• 6-speed automatic
• Rear-wheel drive
• Verify electrical and physical configuration

2016 Subaru BRZ 2.0L Automatic

• FA20
• 6AT
• RWD
• Verify original transmission assembly number

2017 Subaru BRZ 2.0L Automatic

• FA20 2.0L
• Automatic
• RWD
• Verify transmission code and external components

2018 Subaru BRZ 2.0L Automatic

• FA20
• 6-speed automatic
• RWD
• Verify complete physical configuration

The current J-Spec listing identifies 2013–2018 Subaru BRZ as the application range.

SUBARU BRZ / SCION FR-S / TOYOTA 86 PLATFORM

The Subaru BRZ shares its basic platform with the Scion FR-S and Toyota 86.

However, complete automatic-transmission interchange should not be assumed solely because the vehicles share the FA20/4U-GSE platform.

Before applying this transmission to an FR-S or Toyota 86, verify:

• OEM transmission assembly number
• Transmission model code
• VIN
• Production date
• Electrical connectors
• TCM calibration
• Torque converter
• Sensors
• Mounts
• Driveshaft interface
• Shifter electronics

6-SPEED AUTOMATIC / 6AT

This transmission uses six conventional forward gears.

The 6AT configuration is separate from the BRZ’s 6-speed manual transmission.

For customers searching by transmission type, the product should be clearly identified as:

6-Speed Automatic / 6AT

and not simply “6-speed transmission.”

REAR-WHEEL-DRIVE APPLICATION

The Subaru BRZ uses a rear-wheel-drive drivetrain.

Unlike most Subaru models, the BRZ does not use Subaru’s traditional AWD drivetrain configuration.

The transmission output drives the rear differential through a driveshaft.

Before installation, inspect:

• Transmission output
• Tailhousing
• Driveshaft interface
• Transmission mount
• Crossmember
• Driveshaft
• Rear differential compatibility
• Related hardware

JDM-TO-USDM FITMENT

This transmission comes from a Japanese-market application.

Before installation, compare the JDM transmission with the original U.S.-market unit.

Check:

• 31009JB000 assembly number
• TX6A8GD90A transmission model
• Transmission case
• Bellhousing
• Torque converter
• Electrical connectors
• Input/output speed sensors
• Range switch
• Valve-body connections
• Cooler fittings
• Transmission mount
• Tailhousing
• Driveshaft interface
• External brackets
• Wiring

Transfer compatible original USDM components when necessary.

Keep the original transmission and related components until installation and road testing are complete.

WHAT IS INCLUDED?

The sale includes the actual automatic transmission represented in the product photographs.

Depending on the components pictured, the transmission may include:

• 6-speed automatic transmission assembly
• Transmission case
• Internal planetary components
• Valve-body components
• Attached sensors
• Electrical connectors
• Torque converter when pictured
• External brackets when pictured

Only components shown in the actual inventory photos or specifically identified in the listing should be considered included.

ACTUAL PRODUCT PHOTOS

The current J-Spec listing states that customers should review the actual pictures to determine fitment and complete condition of the item for sale.

Use the actual inventory photographs to compare:

• Transmission case
• Bellhousing
• Torque converter
• Electrical connectors
• Sensors
• Cooler fittings
• Tailhousing
• Mounting locations
• External brackets
• Overall condition

AUTOMATIC TRANSMISSION FLUID

Subaru BRZ service information specifies:

Auto Fluid WS

for the automatic transmission.

Use only fluid meeting the required WS specification.

Do not use:

• Subaru CVT fluid
• Subaru Lineartronic CVTF
• Gear oil
• Dexron/Mercon without the required WS specification
• Unverified universal ATF
• Old fluid from the failed transmission

Correct fluid supports:

• Hydraulic pressure
• Shift quality
• Clutch operation
• Torque-converter operation
• Lubrication
• Temperature control

NEVER REUSE OLD TRANSMISSION FLUID

Always start the replacement transmission with fresh WS-specification ATF.

Old fluid may contain:

• Metal particles
• Clutch material
• Friction debris
• Oxidized fluid
• Dirt
• Other contaminants

Contaminated fluid can damage the replacement transmission.

FLUSH THE TRANSMISSION COOLER AND LINES

Thoroughly flush and inspect the transmission cooler and cooler lines before installation.

A failed automatic transmission can circulate:

• Metal particles
• Clutch debris
• Friction material
• Contaminated ATF

through the cooling circuit.

Therefore:

• Flush the transmission cooler.
• Flush cooler lines.
• Inspect for restrictions.
• Remove contaminated fluid.
• Replace components that cannot be properly cleaned.

Never install a replacement transmission onto a contaminated cooling system.

INSPECT THE TORQUE CONVERTER

Compare the replacement torque converter with the original unit.

Inspect:

• Converter hub
• Splines
• Mounting pattern
• Seal surface
• Overall configuration

Make sure the torque converter seats completely inside the transmission before installation.

Never use bellhousing bolts to force the transmission against the engine.

Improper converter installation can damage the transmission pump.

REPLACE ACCESSIBLE SEALS

Inspect accessible seals before installation.

Replace worn or questionable:

• Torque-converter/front seal
• Output seal
• Cooler-line seals
• Shift-shaft seal
• Transmission-pan gasket when applicable
• Other accessible seals

Preventive seal replacement can help reduce future leaks.

INSPECT ELECTRICAL COMPONENTS

Compare the replacement transmission with the original unit.

Inspect:

• Electrical connectors
• Input speed sensor
• Output speed sensor
• Range switch
• Valve-body wiring
• Solenoid connections
• Harness clips

Look for:

• Bent pins
• Corrosion
• Broken wiring
• Damaged connectors
• Physical differences

Transfer compatible original components when required.

INSPECT TRANSMISSION MOUNT AND DRIVESHAFT

Inspect:

• Transmission mount
• Crossmember
• Driveshaft
• Driveshaft flanges
• Joints
• Center support components where applicable
• Related hardware

A worn drivetrain component can create vibration, clunking, or shudder that may appear to be a transmission problem.

SCAN THE VEHICLE BEFORE REMOVAL

Record all diagnostic trouble codes before removing the original transmission.

Pay particular attention to:

• Gear-ratio codes
• Shift-solenoid codes
• Pressure-control codes
• Torque-converter codes
• Speed-sensor codes
• Engine codes
• Communication faults

Use the diagnostic information to help identify the cause of the original transmission failure.

TRANSMISSION INITIALIZATION AND RELEARN

After installation, complete all applicable:

• Diagnostic trouble-code resets
• TCM initialization
• Adaptive learning procedures
• Transmission reset procedures
• Road-test relearn

Use Subaru Select Monitor-compatible equipment or another capable professional diagnostic platform when required.

INITIAL STARTUP CHECKLIST

Before road testing:

• Confirm 2013–2018 Subaru BRZ application.
• Confirm FA20 2.0L engine.
• Confirm 31009JB000 assembly number.
• Confirm TX6A8GD90A transmission model.
• Confirm 6-speed automatic configuration.
• Confirm RWD drivetrain.
• Compare original and replacement transmissions.
• Flush transmission cooler.
• Flush cooler lines.
• Inspect accessible seals.
• Properly seat torque converter.
• Fill with WS-specification ATF.
• Verify proper fluid level.
• Connect all electrical connectors.
• Inspect speed sensors.
• Inspect valve-body wiring.
• Check cooler connections.
• Verify transmission mount.
• Verify driveshaft installation.
• Confirm Park engagement.
• Confirm Reverse engagement.
• Confirm Drive engagement.
• Check warning lights.
• Scan for diagnostic codes.
• Inspect for ATF leaks.

INITIAL ROAD TEST

Begin with a gentle road test.

Monitor:

• Reverse engagement
• Drive engagement
• 1–2 shift
• 2–3 shift
• 3–4 shift
• 4–5 shift
• 5–6 shift
• Downshifts
• Manual shift mode
• Paddle-shift operation when equipped
• Torque-converter lockup
• Shift flare
• Slipping
• Shudder
• Driveline vibration
• Abnormal noises
• Warning lights
• ATF leaks

Avoid aggressive acceleration until normal transmission operation has been confirmed.

After the road test:

• Recheck ATF level.
• Inspect for leaks.
• Scan for diagnostic trouble codes.
• Check cooler connections.
• Inspect mounting hardware.
• Inspect driveshaft connections.

COMMON SIGNS OF SUBARU BRZ AUTOMATIC TRANSMISSION PROBLEMS

A failing BRZ automatic transmission may produce:

• Delayed Drive engagement
• Delayed Reverse engagement
• Harsh shifting
• Transmission slipping
• Shift flare
• Shudder
• Failure to upshift
• Torque-converter problems
• Abnormal transmission noise
• Burnt ATF
• Warning lights
• Diagnostic trouble codes
• Fluid leaks

Similar symptoms may also result from:

• Valve-body problems
• Solenoid faults
• Sensor failures
• Wiring problems
• Torque-converter faults
• Incorrect ATF
• Low fluid
• Contaminated fluid
• Worn transmission mount
• Driveshaft problems

Proper diagnosis should be completed before replacing the transmission.

WHY CHOOSE THIS JDM BRZ 6AT TRANSMISSION?

This JDM 6-speed automatic provides an OEM Subaru replacement option for compatible BRZ models with a damaged, worn, slipping, or failed original transmission.

Key features include:

• Genuine Subaru OEM transmission
• OEM part number 31009JB000
• Transmission model TX6A8GD90A
• FA20 2.0L application
• 6-speed automatic configuration
• RWD drivetrain
• Used JDM low-mileage unit
• Actual inventory photographs
• Individual Item ID
• 90-day limited warranty
• Nationwide freight shipping
• Affordable installation available

WHY BUY FROM J-SPEC AUTO SPORTS?

J-Spec Auto Sports has specialized in Japanese engines, transmissions, and drivetrain components for more than 20 years.

Customers benefit from:

• Actual product photographs
• OEM part-number identification
• Transmission-model information
• Application-specific fitment data
• JDM drivetrain experience
• Nationwide freight shipping
• Local Richmond / Henrico, Virginia pickup
• Affordable installation options
• Limited warranty coverage

INDIVIDUAL INVENTORY INFORMATION

Vehicle: Subaru BRZ
Years: 2013–2018
Engine: FA20 2.0L Boxer 4-Cylinder
OEM Part Number: 31009JB000
Transmission Model: TX6A8GD90A
Transmission: 6-Speed Automatic
Drivetrain: RWD
Fluid: Auto Fluid WS
Item ID: 54940
SKU: MT651
Condition: Used JDM / Low Mileage
Warranty: 90-Day Limited Warranty

90-DAY LIMITED WARRANTY

This individual Item ID 54940 carries a 90-day warranty, subject to J-Spec Auto Sports’ current warranty terms and installation requirements.

Keep installation and service documentation for:

• WS-specification ATF
• Transmission cooler flushing
• Cooler-line flushing
• Seal replacement
• Torque-converter installation
• Professional installation
• Diagnostic procedures
• TCM reset / relearn
• Related maintenance

SHIPPING

Nationwide freight shipping is available throughout the continental United States.

Large drivetrain components are securely prepared for freight transportation. Inspect the shipment and packaging for visible damage when it arrives.

Local pickup is also available in Richmond / Henrico, Virginia.

FREQUENTLY ASKED QUESTIONS

What transmission does the 2013–2018 Subaru BRZ automatic use?

This J-Spec replacement uses Subaru OEM part number 31009JB000, and Subaru parts data associates that assembly with transmission model TX6A8GD90A.

Is this a 6-speed automatic?

Yes. This is a 6-speed automatic / 6AT transmission.

Is this a CVT?

No. The BRZ automatic is a conventional 6-speed torque-converter automatic transmission.

What engine works with this transmission?

This listing targets compatible FA20 2.0L naturally aspirated Subaru BRZ applications.

Is the BRZ transmission AWD?

No. The Subaru BRZ uses rear-wheel drive.

What is part number 31009JB000?

31009JB000 is Subaru’s automatic transmission assembly part number for the application. Subaru parts information shows it superseding earlier assembly number 30098AA050 and associates it with TX6A8GD90A.

What is TX6A8GD90A?

TX6A8GD90A is the transmission-model identification associated with the BRZ automatic transmission assembly in Subaru parts data.

Will it fit a 2013 Subaru BRZ?

It targets compatible 2013 BRZ FA20 automatic applications after complete fitment verification.

Will it fit a 2014 Subaru BRZ?

It targets compatible 2014 BRZ automatic applications.

Will it fit a 2015 Subaru BRZ?

It targets compatible 2015 FA20 6AT applications after verifying the original transmission.

Will it fit a 2016 Subaru BRZ?

It targets compatible 2016 BRZ automatic applications after fitment verification.

Will it fit a 2017 Subaru BRZ?

It targets compatible 2017 BRZ FA20 automatic applications after confirming the original assembly number and configuration.

Will it fit a 2018 Subaru BRZ?

It targets compatible 2018 BRZ automatic applications after complete fitment verification.

Will it fit a Scion FR-S?

The BRZ and FR-S share the same basic platform, but direct interchange should be verified by OEM transmission number, VIN, production date, connectors, and electronic configuration.

Will it fit a Toyota 86?

Certain Toyota 86 applications use related 6-speed automatic transmissions. Verify OEM assembly numbers and complete configuration before ordering.

What transmission fluid does it use?

Use Auto Fluid WS / WS-specification automatic transmission fluid. Subaru BRZ service information identifies Auto Fluid WS for the automatic transmission.

Can Subaru CVT fluid be used?

No. This is not a Subaru Lineartronic CVT.

Can old ATF be reused?

No. Always use fresh correct-specification WS fluid.

Should the transmission cooler be flushed?

Yes. Thoroughly flush and inspect the transmission cooler and cooler lines before installing the replacement transmission.

Does the torque converter need to be seated correctly?

Yes. Proper converter seating is critical before mating the transmission to the engine.

Should accessible seals be replaced?

Inspect accessible seals and replace worn or questionable components before installation.

Does this transmission require a relearn?

Depending on the installation, TCM reset, initialization, adaptive relearn, or related diagnostic procedures may be required.

Is this transmission rebuilt?

No. This is a used OEM JDM transmission, unless specifically stated otherwise.

Are the pictures of the actual unit?

Yes. The live J-Spec page specifically instructs buyers to review all actual pictures for fitment and condition.

Does this transmission have a warranty?

Yes. Item ID 54940 currently carries a 90-day warranty.

Does J-Spec Auto Sports offer installation?

Yes. Affordable installation is available.

Does J-Spec Auto Sports ship nationwide?

Yes. Nationwide freight shipping is available.

ORDER YOUR JDM SUBARU BRZ 31009JB000 6AT TRANSMISSION

Replace your damaged or failed BRZ automatic transmission with this low-mileage JDM Subaru 31009JB000 / TX6A8GD90A 6-speed RWD automatic transmission.

This genuine Subaru OEM transmission targets compatible 2013–2018 Subaru BRZ models equipped with the FA20 2.0L boxer engine and rear-wheel drive.

Vehicle: Subaru BRZ
Years: 2013–2018
Engine: FA20 2.0L
OEM Part Number: 31009JB000
Transmission Model: TX6A8GD90A
Transmission: 6-Speed Automatic / 6AT
Drivetrain: RWD
Fluid: Auto Fluid WS
Item ID: 54940
SKU: MT651
Warranty: 90-Day Limited Warranty

Verify the VIN, production date, original 31009JB000/TX6A8GD90A identification, electrical connectors, sensors, TCM configuration, torque converter, transmission mount, driveshaft interface, cooler fittings, and complete physical configuration before ordering.