2011 Infiniti G37 7-Speed Automatic Transmission: Problems, Identification, and Used Replacement

Part Identification: Confirming the Correct RE7R01A Transmission

The automatic transmission for the 2011 Infiniti G37 is a 7-speed, rear-wheel drive (RWD) unit known as the Jatco JR710E or JR711E. By its Infiniti designation, it is the RE7R01A. This specific assembly is for a narrow range of vehicles: the 2011 G37 Sedan with Rear-Wheel Drive, built between October 2010 (10/10) and May 2011 (05/11). It is paired with the 3.7-liter, non-turbocharged, non-direct-injection engine.

To confirm this is the correct part for your vehicle, you must check several key identifiers during a pre-purchase verification interview with your parts supplier:

What is Included in a Used Assembly

When purchasing a used replacement transmission from a professional auto recycler, industry standards dictate what parts are left on the unit. A standard used RE7R01A assembly includes:

• The main transmission case and all internally lubricated parts.
• The extension/tail housing.
• The transmission oil pan.
• The torque converter.
• The valve body with the integrated Transmission Control Module (TCM).

The assembly will not include external sensors, external wiring harnesses, the shifter, shift linkage/cables, the engine flexplate, or the transmission fluid cooler lines. You must transfer these parts from your original transmission.

Common Failure Symptoms

A failing RE7R01A transmission can present several distinct symptoms. You may notice one or more of the following issues:

• Harsh or delayed shifting, especially when downshifting as you coast to a stop.
• A feeling of hesitation or lag when you accelerate from a stop or after coasting.
• The vehicle entering "limp mode," where it gets stuck in a single gear (often 3rd or 4th) and will not shift.
• The Check Engine Light is illuminated, often with transmission-specific Diagnostic Trouble Codes (DTCs) like P0720, P0741, P0705, or U1000.
• A burning smell, which can indicate overheating fluid.
• Whining or grinding noises from the transmission area.

Diagnosing the Failure

Before condemning the transmission, a few diagnostic steps are necessary. The first step is to scan the vehicle's computer for DTCs. A common and severe fault code is P0720, which points to a malfunction in the output speed sensor circuit. In these transmissions, the issue is rarely the sensor itself but rather a failure of the internally-housed Transmission Control Module (TCM) to which it reports.

Another critical check is the transmission fluid. If the fluid is milky and pinkish, it indicates a catastrophic failure known as the "Strawberry Milkshake of Death" (SMOD). This occurs when the internal wall of the radiator, which contains a chamber for cooling transmission fluid, ruptures. This allows engine coolant and automatic transmission fluid (ATF) to mix, destroying the transmission's internal clutches (specifically the B3 and C1 packs) and electronics.

Diagnostic Flowchart

Known Issues, Bulletins, and Recalls

This transmission family is subject to several well-documented issues. No recalls have been issued for this specific assembly, but multiple TSBs address common complaints.

Shift Responsiveness and Harsh Shifting (TSB ITB12-027 / ITB12-027d & ITB10-075)

Owners of 2009-2011 G37 models often reported harsh downshifts when stopping, hesitation, and jerky behavior at rolling stops. This is a software issue, not a mechanical failure. The official remedy is for an Infiniti dealer to reprogram both the Engine Control Module (ECM) and the Transmission Control Module (TCM) with updated software using the Infiniti CONSULT diagnostic tool.

Internal TCM and Speed Sensor Failure (TSB ITB19-040 / DTC P0720)

This is one of the most severe common failures. The code P0720 indicates a fault with the output speed sensor, but the true cause is typically the failure of the entire internal control unit (the TCM, which is bolted to the valve body) due to heat. This failure forces the transmission into limp mode. The only remedy is to replace or repair the internal control valve/TCM assembly.

Radiator Cooler Cross-Contamination (SMOD)

As mentioned in the diagnosis section, the integrated transmission cooler inside the radiator can fail, mixing coolant with the ATF. This contamination quickly ruins the friction clutches and sensitive electronics inside the transmission. If this occurs, the transmission and the radiator must be replaced, and the cooler lines must be thoroughly flushed to prevent the new transmission from being contaminated by leftover debris.

Freight and Delivery Reality

A replacement RE7R01A transmission is a massive, heavy component. It does not ship in a cardboard box via standard parcel services. Verified shipping data shows this assembly weighs approximately 210 lbs and measures roughly 38" x 24" x 22" before crating.

It will ship via Less-Than-Truckload (LTL) freight on a wooden pallet. If you are having it delivered to a residential address or a shop without a loading dock, you must request liftgate service so the driver can lower the pallet to the ground. Always inspect the transmission for physical damage (such as cracked bellhousings or broken electrical connectors) before signing the driver's delivery receipt.

What Fails at Every Mileage Band

Under 60,000 Miles

Transmissions in this range are generally healthy, but they can suffer from premature fluid degradation ("cooking") due to the transmission's tendency to run hot and the undersized stock cooler integrated into the radiator. Early life valve body/TCM failures are possible but less common. Harsh or jerky shifting (particularly on the 4-3 downshift) is often present but can be fixed with software updates.

• ✓Do during install (required): Perform a full fluid flush and fill with Nissan Matic S ATF. Ensure the replacement unit's TCM has the latest software updates to address known shift quality TSBs. Thoroughly flush all transmission cooler lines to remove any potential debris from the previous unit.
• ✓Do during install (recommended): Replace the transmission pan gasket.
• ✓Cheap insurance while the engine is out: Replace the external input and output shaft seals.

60,000 - 100,000 Miles

This is where internal Valve Body/TCM failures (DTC P0720) become a primary concern, often due to heat stress. Radiator cross-contamination (SMOD) also becomes a significant risk in this window, leading to catastrophic transmission failure.

• ✓Do during install (required): Proactively replace the radiator to prevent future SMOD failure, or bypass the internal cooler and install a dedicated external transmission cooler. Perform a full fluid exchange with Nissan Matic S ATF.
• ✓Do during install (recommended): Replace the internal transmission filter (metal mesh screen) and clean the pan magnets.
• ✓Cheap insurance while the engine is out: Replace the rear main seal on the engine while the transmission is removed. Replace the flexplate if there are any signs of stress or cracking.

100,000 - 150,000 Miles

Valve Body/TCM failures and SMOD remain high risks. Additionally, torque converter failure can occur, which stalls the engine when put into gear and generates significant metal debris (DTC P0741). General wear on internal clutch packs (specifically B3 and C1) is common if the unit was operated with old or contaminated fluid.

• ✓Do during install (required): Replace the radiator if original, or install an external transmission cooler to eliminate the risk of SMOD. Replace the internal filter, pan gasket, and flush cooler lines.
• ✓Do during install (recommended): Strongly consider replacing the torque converter as a preventative measure, especially if the reason for the donor vehicle's salvage status is unknown.
• ✓Cheap insurance while the engine is out: Replace all accessible seals: input shaft, output shaft, and rear main seal. Inspect and consider replacing the driveshaft's center support bearing and flex joint (guibo).

150,000+ Miles

At this stage, there is an increased likelihood of complete mechanical failure due to accumulated wear and tear, especially if fluid maintenance was neglected. The expected service life without fluid changes is around 150,000 to 160,000 miles, though well-maintained units can exceed 200,000 to 270,000 miles.

• ✓Do during install (required): Replace the radiator and install an external transmission cooler without question. Assume the replacement unit will need a new valve body/TCM assembly sooner rather than later; factor this potential cost in.
• ✓Do during install (recommended): Replace the torque converter, internal filter, and pan gasket.
• ✓Cheap insurance while the engine is out: Replace all external seals, the rear main seal, and the transmission and engine mounts, as they are likely worn and stressed during the swap.

Real Owner Experiences

The following table highlights real-world failures, mileages, and costs reported by Infiniti G37 owners.

Repair or Replace?

When faced with a failing RE7R01A, you must decide whether to repair the existing unit or replace the entire assembly.

When Repair Makes Sense: If your transmission is mechanically sound (no slipping, no metal shavings in the pan) but you have a P0720 code, repairing the valve body/TCM makes financial sense. A remanufactured valve body typically costs between $235 and $750. While a dealership might quote over $4,000 for this job, independent shops or DIYers can complete it for $800 to $4,100 depending on labor rates. If your only issue is harsh shifting, a simple software update at the dealership (addressing TSB ITB12-027d) usually costs $150 to $300 and is the most cost-effective first step.

When Replacement is Smarter: Replacement with a used or remanufactured unit is the better option when there is evidence of widespread mechanical failure, such as significant metal shavings in the pan, or in cases of severe radiator cross-contamination (SMOD). Once coolant has circulated throughout the entire unit, it damages the clutches and electronics beyond economical repair. Used replacement units typically run $700 to $1,500, making a full swap cheaper than attempting to rebuild a heavily damaged transmission.

Replacement Cost Expectations

The cost to replace a 2011 G37 transmission varies based on the type of replacement unit. Labor costs for the swap are also significant due to the complexity of the job, which typically takes 5 to 8 hours.

Installation and Programming Essentials

Installing a replacement RE7R01A transmission is an expert-level DIY job or requires a professional shop. Several critical steps must be followed to ensure the replacement unit is not damaged.

Required Tools and Consumables

• Heavy-duty transmission jack.
• Long extensions (30+ inches) with a 19mm swivel socket.
• Infiniti Transmission Fill Adapter (Tool #ATF 180) and a fluid pump.
• Infrared thermometer or professional scan tool.
• Infiniti CONSULT-III Plus scan tool (for programming).
• Nissan Genuine Matic S ATF (approx. 9.7 to 9.75 quarts for a dry fill).
• Internal transmission filter and metal oil pan gasket (OEM Part #31397-1XJ0A).
• Front pump/torque converter input seal.
• Transmission cooler-line flush solvent.

Key Installation Steps & "Gotchas"

• Torque Converter Seating: The torque converter must be rotated until it drops into place three distinct times. Failure to fully seat it will crack the transmission's internal oil pump when the bellhousing is bolted to the engine block.
• Top Bellhousing Bolts: Access is extremely limited. The transmission crossmember must be lowered slightly to tilt the powertrain backward, and very long (30+ inch) socket extensions with a swivel socket are required.
• Fluid Level Check: This transmission has no dipstick. Fluid must be pumped in through an overflow plug on the bottom pan. The engine is then run until the fluid reaches exactly 40°C (104°F), at which point the plug is removed and excess fluid is allowed to drain to a drip.
• Cooler Line Flush: It is mandatory to flush the transmission cooler lines and pressure-test or replace the radiator to prevent debris or coolant from destroying the replacement transmission.

Programming and Calibration

The Transmission Control Module (TCM) is an electronic unit located inside the transmission on the valve body. When the transmission is replaced, the TCM must be electronically "married" to the vehicle's VIN and other control modules. This requires a dealer-level scan tool like the Infiniti CONSULT-III Plus to perform a TCM adaptive relearn and VIN-specific programming. Without proper programming, the car may not start, or the transmission will remain in limp mode.

Frequently Asked Questions (FAQ)