Automatic Transmission Assembly with Engine Stop-Start for 2020-2023 Hyundai
Product Notes Read before buying
This is an 8-speed automatic transmission for front-wheel drive (FWD) models only. It fits vehicles with the 2.5L naturally aspirated (non-turbo) engine and the automatic engine stop/start feature. It will not fit turbo models or vehicles without the stop/start system.
Voice or type your vehicle details and Wrenchy will confirm fitment in seconds.
Vehicle Fitment Guide
This part fits the following vehicles:
| SubmodelSUB- MODEL |
Body Style | Years | Engine | Attributes |
|---|---|---|---|---|
| Preferred | Sedan | 2020 - 2023 | L4 2.5L | FWD | Automatic |
| SE | Sedan | 2020 - 2023 | L4 2.5L | FWD | Automatic |
| SEL | Sedan | 2020 - 2023 | L4 2.5L | FWD | Automatic |
| 2021 - 2022 |
Know This Transmission Before You Buy
The research behind our purchase interview — recalls, bulletins and real install economics for this transmission family:
A quick look at your own vehicle makes sure the right transmission shows up:
- Verify the 8th digit of your VIN is A or Q (naturally aspirated 2.5L Smartstream engine).
- Locate the barcode sticker on top of the transmission bell housing to confirm the A8MF1 code.
- Confirm if your vehicle has Idle Stop & Go (ISG) / automatic engine stop-start.
- Check the driver's side door placard for the TR code.
What the install really takes — plan and budget with confidence:
Special tools this job needs:
- Engine support bar/bridge
- Transmission jack and subframe support stands
- Hyundai-compatible diagnostic scan tool (GDS Mobile or equivalent)
- Fluid fill pump and adapter for sealed transmissions
Budget for these consumables at install:
- Hyundai/Kia Genuine ATF SP-IV-RR or SP-IV-M (sources differ on exact spec)
- Transmission fluid (approx. 6.9 to 9.0 quarts / 6.5 to 8.5 liters depending on dry refill vs drain-and-fill)
- Internal transmission filter (Part Number: 46321-4G300) and pan gasket/RTV sealant
- Front pump input shaft seal (torque converter seal)
- Axle seals
- High-pressure transmission cooler line flush
What your vehicle’s computers will need after the swap:
What’s involved: Solenoid Valve Programming (Oil Pressure Characteristics Input) and TCM Adaptive Values Reset
sources differ: Arm 1 states a 68-digit solenoid calibration code must be written into the TCU via a dealer-level scan tool, while Arm 2 focuses on a mandatory TCM adaptive value reset and relearn drive cycle. Both agree diagnostic programming is required.
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) before bolting to the engine to avoid cracking the internal oil pump.
- The Sealed Fluid Fill Trap: No dipstick. Must check level via overflow plug on the side of the oil pan with engine idling and fluid temperature strictly between 122°F and 140°F (50°C to 60°C).
- Shift-by-Wire (SBW) Alignment: Ensure the electronic actuator is properly aligned and not pinched during subframe installation.
- Adaptive Relearn is NOT Optional: Skipping the TCM adaptive reset and relearn drive cycle will cause poor shift quality and premature wear.
Easy to get right once you know them:
- Ordering for a Turbocharged Model (1.6T or 2.5T N-Line DCT).
- Using standard or generic multi-vehicle ATF instead of the highly specific SP-IV-RR / SP-IV-M fluid.
- Skipping the solenoid calibration or TCM adaptive relearn process.
- Checking fluid level with the engine off, which causes severe underfilling.
- Ignoring the transmission cooler flush, allowing old debris to contaminate the replacement unit.
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:
🔎 Recommended at install: Replace the entire transmission assembly due to porous casting affecting critical internal clutch pack end-play.
🔎 Recommended at install: Diagnose for clutch slippage (DTCs P0730-P0736, P0729, P076F). Requires complete transmission replacement if present without solenoid circuit faults.
🔎 Recommended at install: Write the unique 68-digit solenoid calibration code into the TCM to prevent harsh shifting and premature wear.
🔎 Recommended at install: Replace the input/output speed sensor and harness.
🔎 Recommended at install: Perform software update for the ECM and/or TCM to improve ISG engagement from a stop.
Researched from factory recalls, TSBs and OEM service data (reference unit 400-11121-4944077). Unit-specific details — mileage, condition, warranty, freight — are covered in the checkout interview.
Policies, in plain English.
Shipping & Handling
- Ships by LTL freight on a pallet — a real freight truck, not a parcel van
- Your checkout freight quote covers delivery to your door (liftgate service included for residential addresses)
- The carrier calls ahead to schedule a delivery window — someone must be present to receive it
- Typically palletized and picked up within 2–3 business days; transit time depends on distance
120-Day Warranty
This part includes a 120-day warranty.
- If the part fails within the warranty window, we'll replace it or refund per the coverage terms
- Coverage is parts-only — installation labor is not included
- Warranty covers defects — not installation errors, misuse, or damage after installation
Your pre-purchase interview reviews these exact terms with you before anything is charged.
Returns (30 Days)
We accept returns of uninstalled parts within 30 days of delivery for this part.
- Defective parts: We will replace the part or issue a refund at our discretion
- Programming: "Needs to be programmed to my vehicle" is not a valid return reason. Many modules require dealer programming — we're happy to help connect you with resources if your dealer says it's not programmable
- Return shipping: This part ships by freight (LTL) — the part price is refundable per the terms above, but shipping costs are non-refundable and return freight follows the seller's return terms. Your pre-purchase interview walks through the exact numbers before you buy
- Parts must be returned in original packaging and unmodified condition
- Poorly packaged returns that arrive damaged will not be credited
Damaged in Shipping?
Freight damage is rare — and you're fully protected when you do two things at delivery:
- Inspect before you sign — you're allowed time to look the pallet over while the driver waits
- Write any damage on the delivery receipt before signing — that one line is what makes a freight claim succeed
- Severe damage? Refuse the delivery — it goes back at no cost to you and we make it right
- Photograph the pallet before unwrapping; report concealed damage within 24 hours of delivery
We handle the carrier claim — you just help document it. Your pre-purchase interview walks through this checklist too.
Order Cancellation
Cancel before shipment for a full refund. Once the pallet has been built, a preparation charge may apply — and once the freight carrier picks it up, shipping costs are non-refundable and standard return terms apply. Your pre-purchase interview shows the exact numbers before you pay.
Expert Guides
Related Trouble Codes (OBD-II)
4 matching guidesIf your scan tool is showing one of these trouble codes, this part is a common fix. Each guide explains the code, how to diagnose it, and exactly what to replace.
Miscellaneous Information
OEM Part Numbers:
Hyundai: 450004G610
Fits Years: 2020 2021 2022 2023
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This unit ships with the selling yard's 120-day warranty. Longer plans can be requested during checkout.
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