JDM 1990–1993 Honda / Acura Integra B18 4-Speed Automatic FWD Transmission

Replace your slipping, damaged, noisy, or failed automatic transmission with a low-mileage JDM Honda / Acura Integra automatic transmission from J-Spec Auto Sports.

This genuine Honda drivetrain component targets compatible 1990–1993 Integra models equipped with the B18-series 1.8L engine and front-wheel drive.

The transmission uses a 4-speed electronically controlled automatic transaxle configuration. However, Honda used more than one transmission code during the 1990–1993 Integra generation.

Specifically, the 1990 Integra automatic uses the RO transmission family, while 1991–1993 models use the MPRA 4-speed automatic.

Therefore, buyers should not order solely by model year or the phrase “B18 transmission.”

Instead, verify the physical transmission code, electrical connections, case design, engine application, and vehicle configuration before installation.

J-Spec Auto Sports imports this transmission directly from Japan. In addition, the listing includes actual inventory photos so customers can compare the unit with their original transmission before purchase.

Quick Details

• Vehicle: Honda Integra / Acura Integra
• Model Years: 1990–1993
• Engine Application: B18-Series 1.8L
• Transmission Type: 4-Speed Automatic
• Drivetrain: Front-Wheel Drive / FWD
• 1990 Transmission Code: RO
• 1991–1993 Transmission Code: MPRA
• Condition: Used JDM / Low Mileage
• Origin: Japan
• Item ID: 252
• SKU: MT69
• Photos: Actual Product Photos
• Warranty: 30 Days
• Shipping: Nationwide Freight Shipping
• Local Pickup: Henrico / Richmond, Virginia

Honda / Acura Integra Automatic Transmission Specifications

Honda used an electronically controlled 4-speed automatic transaxle in automatic-equipped second-generation Integra models.

The transmission combines the gearbox and front differential into one front-wheel-drive transaxle assembly.

ATSG documentation describes the 1990 Integra unit as a computer-controlled 4-speed FWD transaxle with a converter clutch, while the 1991–1993 application uses the MPRA designation.

Core Specifications

Transmission Type: Automatic Transaxle
Forward Speeds: 4
Drivetrain: FWD
Engine Application: B18-Series 1.8L
1990 Code: RO
1991–1993 Code: MPRA
Condition: Used OEM/JDM
Origin: Japan

Because the transmission code changes during this generation, the physical code should take priority over a broad year-range description.

Important: 1990 vs. 1991–1993 Transmission Code

This is the most important fitment detail on the page.

1990 Integra Automatic

The 1990 Acura Integra uses the RO 4-speed automatic transmission. ATSG application data specifically lists:

1990 Integra → RO → 4-Speed FWD.

1991–1993 Integra Automatic

The later 1991–1993 Integra uses the MPRA 4-speed automatic transmission.

ATSG application information specifically lists:

1991–1993 Integra → MPRA → 4-Speed FWD.

Therefore, do not assume a 1990 RO and a 1991–1993 MPRA are automatically interchangeable.

Before ordering, verify the actual transmission code stamped on the replacement unit.

Honda Integra vs. Acura Integra

This transmission comes from a Japanese-market Honda application.

In Japan, the vehicle carries the Honda Integra name.

Meanwhile, U.S.-market versions were sold as the Acura Integra.

For SEO and customer clarity, this listing should use both names naturally:

Honda Integra / Acura Integra

Doing so helps customers searching for JDM parts while also matching the terminology used by U.S. vehicle owners.

B18 Engine Application

This transmission targets compatible Integra applications equipped with Honda’s B-series 1.8L engine family.

U.S.-market RS, LS, and GS models commonly used the B18A1 1.8L DOHC non-VTEC engine during this generation. The 1990–1993 service information identifies B18A1 applications in DA9 hatchback and DB1 sedan models.

However, buyers should still verify the engine and transmission combination before purchase.

Do not order only because the vehicle has a B18 engine.

Different B-series applications can use different transmissions, mounts, electronics, or case configurations.

DA9 and DB1 Chassis Applications

The second-generation Integra includes several chassis configurations.

Common U.S.-market applications include:

• DA9: 2-door hatchback / liftback
• DB1: 4-door sedan

Service information identifies both DA9 and DB1 with B18A1 engines and MPRA automatic transmissions in applicable configurations.

Therefore, body style alone does not determine fitment.

Always verify the original transmission.

MPRA Transmission Application

For 1991–1993 models, the MPRA code provides a much stronger fitment identifier than simply saying “B18 automatic.”

The MPRA is a 4-speed FWD automatic transaxle used in compatible Integra applications.

If the physical transmission shown in this J-Spec listing carries an MPRA code, I recommend changing the Product Code field from:

B18 Transmission

to:

MPRA

That change would improve both technical accuracy and search visibility.

Customers frequently search by transmission code when replacing older Honda automatic transmissions.

JDM-to-USDM Fitment

This transmission came from a Japanese-market vehicle.

Although the core transmission may serve as a replacement for compatible U.S.-market Acura Integra models, JDM-to-USDM differences can exist.

Before installation, place the replacement transmission next to the original USDM unit.

Compare:

• Transmission code
• Transmission case
• Bellhousing
• Electrical connectors
• Shift solenoids
• Lock-up solenoids
• Sensors
• Wiring
• Transmission mounts
• Brackets
• Axle connections
• Cooler-line fittings
• Shift linkage
• Torque converter

When necessary, transfer compatible external USDM components.

Most importantly, do not modify the transmission or wiring until fitment has been confirmed.

What Is Included?

The sale includes the actual Honda Integra automatic transmission shown in the product photos.

Depending on the individual unit, attached components may include:

• Complete automatic transaxle
• Transmission housing
• Internal geartrain
• Valve-body components
• Factory solenoids that remain attached
• Sensors that remain attached
• Electrical connectors
• Torque converter when pictured or specifically stated
• Brackets when pictured

Please review every actual product photo carefully.

Only components shown in the photos or specifically stated in the listing should be considered included.

Recommended Installation Procedure

Correct installation plays a major role in the life of any replacement automatic transmission.

Therefore, determine why the original transmission failed before installing the JDM replacement.

Diagnose the Original Transmission Failure

First, inspect the vehicle and determine the cause of the original problem.

Possible causes include:

• Internal clutch wear
• Valve-body problems
• Shift-solenoid faults
• Lock-up-solenoid faults
• Electrical problems
• Low fluid level
• Contaminated fluid
• Transmission overheating
• Cooler restrictions
• Worn mounts

Fixing the original problem helps protect the replacement transmission.

Verify the Transmission Code

Before installation, confirm the code on both the original and replacement transmission.

For this generation:

1990 → RO

1991–1993 → MPRA

Do not skip this step.

The transmission code provides a much stronger fitment reference than engine size alone.

Flush the Transmission Cooler and Lines

Thoroughly clean the transmission cooler and cooler lines before connecting the replacement unit.

A failed automatic transmission can circulate:

• Metal particles
• Clutch material
• Contaminated ATF
• Debris

Consequently, contamination left in the cooling circuit can enter the replacement transmission shortly after startup.

Clean the complete cooler system.

If the cooler cannot be properly cleaned, replace it.

Use the Correct Honda-Specified ATF

Fill the transmission with the correct Honda-compatible automatic transmission fluid for the exact application.

Do not reuse old fluid from the failed transmission.

Likewise, avoid choosing fluid solely because a generic label claims compatibility with many manufacturers.

The 1991–1993 MPRA transmission has a total fill capacity listed around 6.7 quarts, with approximately 3.2 quarts for a typical initial service fill, although actual replacement fill quantity depends on how completely the unit and converter were drained.

Always follow the appropriate Honda/Acura service procedure when setting fluid level.

Never Reuse Contaminated ATF

Old transmission fluid can carry:

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

Therefore, start the replacement transmission with fresh fluid.

Using contaminated ATF can shorten the life of the replacement unit.

Inspect the Torque Converter

Next, inspect the torque converter and confirm compatibility.

Make sure the converter fully seats inside the transmission before installation.

Improper seating can damage the transmission pump during startup.

Therefore, never use bellhousing bolts to force the transmission against the engine.

Inspect Accessible Seals

Check accessible seals while the transmission remains outside the vehicle.

Pay particular attention to:

• Axle seals
• Torque-converter seal
• Shift-shaft area
• Cooler fittings
• Case sealing surfaces

Replace worn or leaking seals before installation.

Doing this work now can prevent unnecessary labor later.

Inspect Engine and Transmission Mounts

Older Integra mounts can deteriorate after decades of use.

Worn mounts may cause:

• Excessive drivetrain movement
• Vibration
• Clunking
• Harsh engagement
• Abnormal axle angles

Therefore, inspect all accessible mounts before installing the replacement transmission.

Replace damaged components as necessary.

Inspect the Axles

Check the axle splines and CV joints before installation.

Look for:

• Damaged splines
• Torn boots
• Excessive play
• Grease leakage
• Worn joints

A worn axle can create vibration or noise that customers may incorrectly blame on the replacement transmission.

Check Shift and Lock-Up Solenoids

The early Integra automatic transmission uses electronically controlled shifting and converter lock-up.

Therefore, inspect the external solenoids and wiring carefully.

Check for:

• Damaged connectors
• Broken wires
• Corrosion
• Fluid contamination
• Physical damage

ATSG documentation confirms electronic shift and lock-up control on this transmission design.

Transfer compatible original components when necessary.

Scan and Diagnose Electronic Problems

Because these early Honda automatic transmissions use electronic controls, electrical problems can create transmission-like symptoms.

Before condemning the original gearbox, check:

• Transmission control system
• Solenoid circuits
• Wiring
• Vehicle speed inputs
• Engine control inputs
• Related diagnostic codes

Correct any electronic problem before operating the replacement unit.

Initial Startup Checklist

Before road testing:

• Verify transmission code.
• Confirm correct ATF level.
• Check electrical connectors.
• Inspect cooler-line connections.
• Check axle seals.
• Verify shift linkage adjustment.
• Confirm Park operation.
• Confirm Reverse engagement.
• Confirm Drive engagement.
• Check for warning lights.
• Listen for abnormal noises.
• Inspect for ATF leaks.

If anything appears abnormal, diagnose the problem before driving.

Initial Road Test

Begin with a gentle road test.

During the drive, verify:

• Smooth Reverse engagement
• Smooth Drive engagement
• Proper 1–2 shift
• Proper 2–3 shift
• Proper 3–4 shift
• Normal downshifts
• Normal converter lock-up
• No slipping
• No flare between shifts
• No abnormal noises
• No fluid leaks

Afterward, inspect the transmission again and verify the fluid level.

Common Signs of Integra Automatic Transmission Problems

A worn Integra automatic transmission may produce:

• Slipping
• Delayed Drive engagement
• Delayed Reverse engagement
• Harsh shifting
• Shift flare
• Failure to shift
• Converter lock-up problems
• Abnormal noises
• Burnt ATF
• Fluid leaks
• Solenoid-related problems

However, these symptoms do not always mean the complete transmission has failed.

For example, shift solenoids, wiring, incorrect fluid level, worn mounts, or electronic control problems can produce similar symptoms.

Therefore, diagnose the vehicle before replacing the transmission.

Why Choose a Low-Mileage JDM Integra Transmission?

A Japanese-import transmission can provide an OEM-based replacement option for an older Integra with a worn or damaged original gearbox.

Benefits include:

• Genuine Honda OEM construction
• Low-mileage Japanese donor unit
• 4-speed automatic configuration
• FWD drivetrain
• B18-series application
• Actual inventory photos
• Individual Item ID
• 30-day limited warranty
• Nationwide shipping

In addition, clean replacement transmissions for early second-generation Integras are becoming harder to find.

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.

Our team supplies JDM engines, automatic transmissions, manual transmissions, and other drivetrain components to repair facilities, enthusiasts, and vehicle owners throughout the United States.

Rather than operating as a general salvage yard, we specialize in Japanese engines and transmissions.

Actual Product Photos

This listing includes actual product photographs.

Therefore, customers can inspect the physical condition and configuration of the transmission before purchasing.

Compare those photos carefully with the original transmission.

Individual Inventory Identification

This listing carries:

Item ID: 252
SKU: MT69

The individual inventory number gives customers and J-Spec Auto Sports staff a specific reference during fitment verification and ordering.

Nationwide Shipping

J-Spec Auto Sports ships JDM engines and transmissions throughout the continental United States.

Therefore, customers nationwide can purchase this Integra automatic transmission.

Local Virginia Pickup

Local pickup is available from J-Spec Auto Sports in Henrico, Virginia.

Customers throughout Richmond, Central Virginia, Northern Virginia, Maryland, Washington D.C., and surrounding areas can also arrange pickup.

Shipping

J-Spec Auto Sports can prepare this automatic transmission for nationwide freight shipment.

Shipping costs depend on:

• Destination ZIP code
• Commercial or residential delivery
• Liftgate requirements
• Freight-terminal availability
• Delivery location

Before accepting the shipment, inspect the pallet and transmission for visible freight damage.

If damage exists, document it with the carrier immediately.

30-Day Warranty

J-Spec Auto Sports backs this transmission with a 30-day limited warranty, subject to current warranty terms and installation requirements. The current live product page confirms the 30-day warranty.

Review the complete warranty policy before installation.

Also keep receipts for:

• Automatic transmission fluid
• Replacement seals
• Cooler flushing
• Professional installation
• Related maintenance

Frequently Asked Questions

What automatic transmission does a 1990 Acura Integra use?

The 1990 Acura Integra automatic application uses the RO 4-speed FWD transmission.

What transmission does a 1991–1993 Acura Integra use?

Compatible automatic-equipped 1991–1993 Integra models use the MPRA 4-speed FWD automatic transmission.

Is this a 4-speed transmission?

Yes. The automatic Integra transmission in this generation uses a 4-speed configuration.

Is this transmission front-wheel drive?

Yes. It is designed for compatible FWD Integra applications.

What engine works with this transmission?

This listing targets compatible B18-series 1.8L Integra applications, including B18A-family configurations.

Will this fit a 1990 Acura Integra?

Do not assume fitment until the transmission code has been checked. A 1990 automatic uses the RO transmission code, while later 1991–1993 models use MPRA.

Will this fit a 1991 Acura Integra?

If the physical transmission is an MPRA and the remaining configuration matches, it targets compatible 1991 automatic Integra applications.

Will it fit a 1992 Acura Integra?

Compatible 1992 B18A1 automatic models use the MPRA transmission family.

Will it fit a 1993 Acura Integra?

Compatible 1993 automatic Integra models also use the MPRA family. Verify the original transmission and external components before ordering.

Is Honda Integra the same as Acura Integra?

Honda sold the Integra under the Honda name in Japan, while U.S.-market vehicles used the Acura Integra name. Fitment still depends on the specific drivetrain and transmission configuration.

What does MPRA mean?

MPRA is Honda’s transmission identification code for the 4-speed automatic used in compatible 1991–1993 Integra applications.

Is MPRA the same as RO?

No. RO identifies the 1990 Integra automatic transmission, while MPRA identifies the 1991–1993 application. Do not assume direct interchange.

Is this transmission rebuilt?

No, unless specifically stated otherwise. This listing represents a used low-mileage JDM/OEM transmission.

Does it include a torque converter?

Only consider the torque converter included if it appears in the current actual product photos or the listing specifically states that it comes with the transmission.

Should I flush the transmission cooler?

Yes. Thoroughly clean the cooler and lines before installing the replacement transmission.

Can I reuse the old ATF?

No. Always start the replacement transmission with fresh, correct-specification fluid.

Do I need to transfer parts from my original transmission?

Possibly. JDM-to-USDM differences may require transferring compatible solenoids, sensors, brackets, wiring components, or other external parts.

Does this transmission have a warranty?

Yes. J-Spec Auto Sports provides a 30-day limited warranty, subject to current warranty terms.

Do you ship nationwide?

Yes. J-Spec Auto Sports ships transmissions throughout the continental United States.

Can I pick it up locally?

Yes. Local pickup is available from J-Spec Auto Sports in Henrico, Virginia.

How do I verify fitment?

Provide your:

• Vehicle year
• VIN
• Engine code
• Original transmission code
• Body style
• Photos of the original transmission
• Photos of the electrical connectors
• Photos of the transmission code stamp

For the best fitment verification, compare the transmission case, bellhousing, solenoids, connectors, mounts, axles, cooler fittings, and torque converter.

Order Your JDM Honda / Acura Integra Automatic Transmission

If your 1990–1993 Honda or Acura Integra needs a replacement automatic transmission, this low-mileage JDM 4-speed FWD transmission provides an OEM Honda-based replacement option for compatible B18 applications.

J-Spec Auto Sports provides actual inventory photos, nationwide freight shipping, individual inventory identification, and a 30-day limited warranty.

Verify the physical transmission code before ordering. A 1990 Integra uses the RO transmission family, while 1991–1993 automatic models use MPRA.