Transmission Assembly for 2024 GMC Terrain
Product Notes Read before buying
This is for All-Wheel Drive (AWD) models equipped with the 1.5L engine and 9-speed automatic transmission (GM option code M3U). It will not fit Front-Wheel Drive (FWD) vehicles.
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 |
|---|---|---|---|---|
| 2024 |
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 vehicle is AWD (5th digit of VIN indicates chassis/drivetrain type).
- Scan the QR code on the driver's door B-pillar to verify RPO code M3U and engine code LYX or LSD.
- Verify the GM Part Number or Broadcast Code on the transmission tag matches a 9T45 AWD unit.
- Physically confirm a Power Transfer Unit (PTU) is bolted to the passenger side of the transmission.
What the install really takes — plan and budget with confidence:
Special tools this job needs:
- Engine support bridge/fixture
- Transmission jack
- DT-47811-A Lift Plate
- DT-46409 Torque Converter Lifting Handles
- GM-compatible OBD-II scan tool with Techline Connect / SPS2 capability
Budget for these consumables at install:
- GM DEXRON-VI Full Synthetic ATF (GM Part # 88865601 or equivalent licensed fluid)
- Control valve body side cover gasket / Transmission filter kit
- Torque converter fluid seal (GM Part # 24266190 or 24262294)
- Left and right CV axle seals (GM Part # 24288437 / 24273970)
- Transmission cooler-line flush
What your vehicle’s computers will need after the swap:
What’s involved: Solenoid Characterization Programming, VIN-specific TCM Programming, and Transmission Service Fast Learn
Requires programming the 11-digit or 16-digit Part Unique Number (PUN) etched on the transmission case/valve body cover into the TCM using GM Techline Connect / SPS2. Additionally, a VIN-specific TCM programming and Transmission Service Adaptation (Fast Learn) must be performed to prevent immediate transmission damage.
Pro tips for a smooth first start-up — hand them to whoever does the install:
- Torque Converter Seating: Ensure the torque converter is fully seated (typically 2-3 distinct drops/clicks) before bolting to the engine to avoid cracking the internal fluid pump.
- AWD PTU Alignment: Carefully align and bolt the Power Transfer Unit (PTU) to the transmission, ensuring clean, lubricated splines and undamaged seals.
- Subframe Removal: Dropping the transmission requires lowering or removing the front subframe/cradle while supporting the engine from above.
- Fluid Level Check Procedure: No dipstick. Must check with vehicle level, engine running, fluid temp at 185°F to 203°F (85°C to 95°C), using the fluid level set plug on the side of the case.
- Solenoid Characterization (PUN): Record the PUN and TUN from the barcode labels on the transmission case before installation, as they are extremely difficult to see once installed.
Easy to get right once you know them:
- Ordering FWD instead of AWD: FWD cases lack the mounting bosses and output configuration for the PTU.
- Skipping Solenoid Characterization: Skipping the PUN programming causes immediate harsh shifts and can burn up clutches within a few miles.
- Checking Fluid Cold: Checking fluid level cold or with the engine off leads to severe underfilling or overfilling.
- Reusing Pump Bolts: Reusing single-use torque-to-yield pump bolts on units affected by TSB 25-NA-001 causes leaks.
- Using the Wrong Fluid: Confusion between DEXRON VI and DEXRON ULV. DEXRON VI is required.
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: Inspect the snap ring on the clutch spring or backing plate before installation. Replace if out-of-round.
🔎 Recommended at install: Replace transmission pump bolts using single-use bolt kit (Part # 24044946) before installation.
🔎 Recommended at install: Perform solenoid characterization or valve body cleaning if DTCs P0746 or P0747 are set.
🔎 Recommended at install: Diagnose high-pitched whine heard at 20–35 mph under light to moderate acceleration.
🔎 Recommended at install: Inspect fluid condition and check for internal mechanical failures.
Researched from factory recalls, TSBs and OEM service data (reference unit 400-12084-5326449). 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
2024 GMC Terrain 1.5L AWD 9T45: Problems, Identification, and Used Replacement
Identify the exact M3U transmission, understand common snap ring and fluid leak failures, and learn when to replace it with a verified used OEM assembly.
Read Full Guide →Related Trouble Codes (OBD-II)
3 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:
GM: 24047445
Fits Years: 2024
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Backed By The Selling Yard
This unit ships with the selling yard's 120-day warranty. Longer plans can be requested during checkout.
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