9-Speed Automatic Transmission Assembly for 2020-2021 GMC Acadia - Front
Product Notes Read before buying
This is a 9-speed automatic transmission (GM option code M3H) for Front-Wheel Drive (FWD) models equipped with the 2.5L engine. It will not fit All-Wheel Drive (AWD) vehicles or models with the 2.0L or 3.6L engines. Professional installation and dealer-level programming may be required for proper functionality.
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 |
|---|---|---|---|---|
| AT4 | SUV | 2020 - 2021 | V6 3.6L | AWD/4WD | Automatic |
| Denali | SUV | 2020 - 2021 | V6 3.6L | AWD/FWD/4WD | Automatic |
| SL | SUV | 2020 - 2021 | L4 2.5L | FWD | Automatic |
| SLE | SUV | 2020 - 2021 | L4 2.0L Turbo | FWD/4WD | Automatic |
| SLE | SUV | 2020 - 2021 | L4 2.5L | FWD/4WD | Automatic |
| SLE | SUV | 2020 - 2021 | V6 3.6L | FWD/4WD | Automatic |
| SLT | SUV | 2020 - 2021 | L4 2.0L Turbo | FWD/4WD | Automatic |
| SLT | SUV | 2020 - 2021 | V6 3.6L | FWD/4WD | Automatic |
| Black | SUV | 2021 | V6 3.6L | AWD | Automatic |
| Denali | SUV | 2021 | L4 2.0L Turbo | FWD/4WD | Automatic |
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:
- Confirm the 8th digit of the VIN is 'A' (designating the 2.5L LCV 4-cylinder engine).
- Verify the transmission RPO code is M3H on the driver's side B-pillar QR code label or glove box sticker.
- Confirm the vehicle is Front-Wheel Drive (FWD) only.
- Confirm the vehicle has Electronic Precision Shift push-button gear controls instead of a mechanical shift lever.
What the install really takes — plan and budget with confidence:
Special tools this job needs:
- GM-compatible diagnostic scan tool (MDI2 with GDS2/SPS2 software subscription)
- Transverse engine support fixture / engine support brace
- Transmission jack
- Torque converter holding tool
- Digital thermometer or OBD-II scanner
- Torque wrench
Budget for these consumables at install:
- GM DEXRON-VI synthetic automatic transmission fluid
- Side cover gasket (if cover is removed)
- Torque converter seal
- Axle shaft seals
- High-pressure transmission cooler line flush solvent
What your vehicle’s computers will need after the swap:
What’s involved: SPS Solenoid Characterization Reprogramming (MCVM) & Transmission Adaptive Values Learn
Requires a GM dealer-level scan tool (GDS2/SPS2) to enter the Transmission Unique Number (TUN) from the barcode label to pull solenoid calibration data from the GM cloud and marry it to the VIN/TCM. A Service Fast Learn / Transmission Adaptive Values Learn procedure must then be performed to learn clutch fill times.
Pro tips for a smooth first start-up — hand them to whoever does the install:
- Torque Converter Seating: Must be fully seated into the front pump in three distinct steps. If not fully recessed, tightening the bellhousing bolts will crack the internal oil pump gear, destroying the transmission instantly.
- Highly Sensitive Fluid Level Check: No dipstick. Fluid level must be checked via the leveling plug on the side of the case with the vehicle level and fluid temperature precisely between 85°C and 95°C (185°F to 203°F) with the engine idling in Park.
- Start-Stop Accumulator Inspection: Inspect and torque the accumulator endcap bolts to spec before installation to prevent severe fluid leaks.
- Driveline & Subframe: The entire subframe must be lowered or removed to access and remove the transmission, requiring careful support of the engine and chassis.
Easy to get right once you know them:
- Skipping the Solenoid Characterization (TUN Programming) and assuming the unit is plug-and-play.
- Reusing contaminated cooler lines without performing a high-pressure flush.
- Checking the transmission fluid level cold or outside the strict temperature window.
- Ordering the transmission for the wrong engine (2.0L Turbo or 3.6L V6) or wrong drivetrain (AWD models).
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: Physically inspect the accumulator bolts on the replacement unit and ensure they are present and torqued to factory specifications before installing.
🔎 Recommended at install: Update TCM software and perform a Service Fast Learn procedure.
🔎 Recommended at install: Inspect vehicle's cooler and lines for contamination before hooking them up to the new transmission.
🔎 Recommended at install: Follow diagnostic guidelines for control solenoid and valve DTCs.
🔎 Recommended at install: Check transmission fluid for contamination. Perform fluid drain and refill with DEXRON VI, or full torque converter replacement.
🔎 Recommended at install: Replacement of both upper and lower valve body assemblies. Replacing the TCM is not effective.
🔎 Recommended at install: Re-secure or replace input clutch housing retaining snap-ring to prevent total loss of forward drive or Reverse.
🔎 Recommended at install: Replace the 4th clutch Torrington bearing if whining or whirring noise is present in 4th gear.
🔎 Recommended at install: Ensure fluid is completely free of microscopic metallic debris to prevent erratic shifting or limp mode.
Researched from factory recalls, TSBs and OEM service data (reference unit 400-10787-5509388). 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
2020-2021 GMC Acadia 2.5L 9T50 Transmission: Problems, Identification, and Used Replacement
Identify the GM Hydra-Matic 9T50, learn what causes it to fail, and know exactly what to look for when replacing it with a used OEM unit.
Read Full Guide →Related Trouble Codes (OBD-II)
2 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:
GMC: 19419972, 24286814
Other: 0DMB
Fits Years: 2020 2021
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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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