Automatic Transmission Assembly for 2016-2017 Mazda 6

A quick look at your own vehicle makes sure the right transmission shows up:

• Verify the 8th digit of the VIN is '5' or '6' (naturally aspirated 2.5L engine).
• Confirm the vehicle does NOT have the i-ELOOP regenerative braking system (check for silver capacitor behind driver's side bumper or i-ELOOP graphic in cluster).
• Verify the vehicle is Front-Wheel Drive (FWD) and not All-Wheel Drive (AWD).
• Check that the original transmission case casting stamp reads 'FZ21' or 'FZ01'.

What the install really takes — plan and budget with confidence:

Special tools this job needs:

• Engine support bar/brace
• Transmission jack
• Axle seal protectors
• Advanced OBD-II scan tool with Mazda TCM initial learning capability

Budget for these consumables at install:

• Mazda Genuine ATF-FZ (Type FZ) fluid (approx. 8.2 quarts total capacity, 4.0 to 5.0 quarts for service refill)
• Transmission oil filter (Mazda Part # FZ01-21-500)
• High-quality transmission-grade RTV silicone or aftermarket pan gasket
• Torque converter input shaft seal
• Left and right axle seals (Mazda Part # FZ01-27-238 for passenger side)
• Transmission cooler-line flush solvent

What your vehicle’s computers will need after the swap:

What’s involved: TCM Adaptive Relearn (Initial Learning)

sources differ: Arm 1 states no VIN-specific remarriage is required, only TCM Initial Learning via an advanced scan tool. Arm 2 notes some sources indicate the TCM is VIN-locked, which may require dealer-level programming if the valve body/TCM is replaced — confirm with us before install

Pro tips for a smooth first start-up — hand them to whoever does the install:

• Torque Converter Seating: Must be fully seated (typically three distinct clicks/drops) before bolting to the engine to avoid cracking the internal oil pump gear.
• The Case Plug Transfer (TSB #SA-053-20): Must transfer a specific plug from the old transmission case to the replacement unit with a new washer.
• Shifter Cable Alignment: Must be perfectly aligned at the manual lever to prevent shift codes or a no-start condition.
• Fluid Level Check Procedure: No standard engine-bay dipstick. The short dipstick is secured by a 10mm bolt low on the case. Fluid level must be checked with ATF temperature between 122°F and 140°F (50°C to 60°C) on level ground with the engine idling.
• Case-Mounted Cooler: This model uses a case-mounted cooler. Ensure it is thoroughly flushed or replaced to prevent old debris from contaminating the new unit.

Easy to get right once you know them:

• Using Non-FZ Fluid: Filling with standard multi-vehicle ATF or Type M fluid instead of Mazda Genuine ATF-FZ (blue color) causes immediate slipping and clutch failure.
• Skipping the Adaptive Relearn: Driving without performing the TCM Initial Learning procedure leads to violent shifting and trouble codes.
• Ordering for an i-ELOOP Vehicle: Purchasing this unit for a vehicle equipped with the i-ELOOP regenerative braking system (different wiring and TCM calibration).
• Reusing Contaminated Cooler Lines/Cooler: Failing to flush the cooler system, which washes metal shavings from the failed unit directly into the replacement transmission.
• Misdiagnosing the Problem: Replacing the transmission for a whining noise that is actually a bad wheel bearing.

Not issues with the units on this page — the manufacturer documented these for every transmission of this family, wherever you buy one. Handy for your installer: