How do I know what transmission I have in my Chevy?

The quickest way to know is to check the vehicle’s records or the transmission tag on the unit itself; the VIN/build sheet or window sticker will identify the exact transmission installed in your Chevy. If you don’t have easy access to those records, you can also inspect the car for labels and gear patterns that point to the correct model.

Check official vehicle records

Use the car’s documentation and official records to identify the transmission. This approach relies on the VIN, the build sheet, and the labels that GM provides with the vehicle.

• Locate the 17‑digit VIN (vehicle identification number) and use Chevrolet’s official VIN decoder or the My Chevrolet/GM service portals to pull the build sheet. The build sheet or “RPO” (Regular Production Option) section will list the transmission model or code that was installed at the factory.


• Inspect the driver’s side door jamb sticker or the glovebox/monroney window sticker for RPO codes. Cross‑reference any transmission‑related code with GM’s published RPO lists to determine the exact transmission.


• Review the window sticker (Monroney) if you still have it; some builds show the transmission as standard or optional, which can confirm the type used in that trim and year.

Relying on official records is the most reliable way to confirm the exact transmission for your Chevy. If you can’t locate the build sheet or sticker, contact a dealer or GM customer care with your VIN for a definitive answer.

Physical inspection and on-vehicle clues

If official records aren’t readily available, you can sometimes identify the transmission by examining the vehicle itself and noting certain clues.

• Look for a tag or stamped label on the transmission housing (often on the bell housing side or near the cooler lines). The tag or stamping typically lists the transmission model code or family, which you can cross‑reference with GM documentation.


• Check the transmission pan or the area around the transmission for a model/series plate or sticker. Many GM transmissions carry a readable code or part number that identifies the exact unit.


• Observe the shift mechanism and the number of speeds shown by the gear selector. Modern Chevrolets commonly use 6‑, 8‑, or 9/10‑speed automatics; manual transmissions are rarer in new Chevys but can be present on specific trims or older models. The gear count can help narrow down the likely transmission family, though it may not be definitive without a code.

Physical clues can be helpful, but they may not distinguish between closely related GM transmission families. If you’re unsure after a visual check, move to the professional routes below.

Getting a definitive answer from a dealer or shop

When records and visual checks aren’t conclusive, involve a dealership or a trained shop. They can pull the exact transmission information using GM’s diagnostic tools and official data sources.

• Provide the VIN to the service adviser; they can retrieve the vehicle’s build sheet, RPO codes, and the exact transmission specification from GM’s databases.


• Ask for the transmission code or model name as listed in the vehicle’s service history or production documentation, or request a copy of the build sheet if available.


• If you want to verify yourself, request a printout from the dealer or use a reputable VIN decoding service that includes transmission information tied to GM vehicles.

Dealer or certified shop access to GM’s tooling typically yields a precise answer, which is especially important for maintenance, parts compatibility, and future repairs.

Summary

To know which transmission is in your Chevy, start with official records: pull the build sheet via the VIN, read the RPO codes on the door sticker or window sticker, and confirm with the dealer if needed. If those records aren’t available, inspect the transmission tag or label on the unit, and note the gear count as a clue. When in doubt, a dealer or qualified shop can pull the exact specification using GM’s internal systems and provide a definitive answer for maintenance and parts purposes.

How do I tell if my transmission is a 4L60E or 4L80E?

You can tell the difference between a 4L60E and 4L80E by checking the transmission pan shape, which is a reliable visual cue: the 4L60E has a rectangular pan with 16 bolts, while the 4L80E has a larger, more irregular (often described as rectangular with clipped corners) pan with 17 bolts. The 4L80E is also physically larger, heavier, and was used in heavier-duty applications like 2500/3500 series trucks and SUVs.
 
Pan shape and bolt count

• 4L60E: Rectangular pan with 16 bolts.
• 4L80E: Irregularly shaped pan (like a rectangle with two clipped corners) with 17 bolts. 

Size and weight

• 4L60E: Lighter and smaller, weighing around 150 lbs.
• 4L80E: Significantly larger and heavier, weighing around 236 lbs. 

Vehicle application

• 4L60E: Used in light-duty applications like 1500 series trucks and SUVs. 
• 4L80E: Heavy-duty transmission used in 2500/3500 series trucks, heavy-duty Suburbans, and vans. 

Will my VIN number tell me what transmission I have?

Yes, you can often tell your transmission type by checking the VIN, but it's not guaranteed because transmission data isn't always encoded in the VIN according to a single standard. To find out for sure, you can use the VIN with an online decoder like the NHTSA VIN decoder, check with a dealership's parts department, or look for physical identifiers on the vehicle itself. 
How to find your transmission using the VIN

• Use an online VIN decoder: Input your 17-character VIN into a decoder, such as the one provided by the National Highway Traffic Safety Administration (NHTSA). Look for a "Transmission" or "Engine" category in the results. This is the most direct way, but it may only provide basic information like "manual" or "automatic". 
• Contact a dealership: Provide the VIN to the parts department of your vehicle's dealership. They can look up your specific vehicle's original factory options and tell you the exact transmission it was built with. 
• Check the vehicle's build sheet or window sticker: If you have them, these documents will list the original factory options for your vehicle, including the transmission type. 
• Use a specialized decoder (if available): For certain vehicle brands, like BMW, there are specialized online resources (e.g., RealOEM) that can provide detailed information by inputting the last seven digits of the VIN. 

If the VIN doesn't provide the answer

• Inspect the physical transmission: Crawl under the vehicle and look for a tag on the transmission itself, which will have a specific model number. You can also get a general idea of the type by looking at the shape of the oil pan or checking online for images of your vehicle's transmission.
• Provide other vehicle information: If the VIN decoder doesn't work, provide your vehicle's make, model, year, and engine size to a knowledgeable person or online forum, and they may be able to determine the correct transmission based on that information. 

How do I know if I have a 6L80 or 6L90?

The main ways to identify a 6L80 from a 6L90 are by the RPO code (6L80=MYC, 6L90=MYD), the length, and the pan shape. The 6L90 is a heavier-duty version that is approximately 1-3/8 inches longer and has a pan with a flatter corner, while the 6L80 is shorter and has a more rounded pan corner. You can also check the part numbers or look at specific internal components if you have the transmission disassembled.
 
Key identification methods 

• RPO Code: Look for the RPO (Regular Production Option) code on the glovebox or vehicle service tag. 
  • MYC: indicates a 6L80. 
  • MYD: indicates a 6L90. 
• Transmission Length: The 6L90 is longer than the 6L80. 
  • 6L80: Case with bell housing length is approximately 23.5 inches. 
  • 6L90: Case with bell housing length is approximately 25 inches (1-3/8 inches longer). 
• Transmission Pan: The shape of the transmission pan is a reliable indicator when the unit is out of the vehicle. 
  • 6L80: The pan has a rounded corner on the back. 
  • 6L90: The pan has a flatter corner on the back. 
• Part Numbers: GM part numbers for transmission parts often begin with 242. The specific part number on the TEHCM sticker (under the transmission pan) can help identify the exact model and year. 

How do I tell which Chevy transmission I have?

You can identify your Chevy transmission by checking the vehicle's owner's manual, looking for a label or stamped code on the transmission itself, or finding a RPO (Regular Production Option) code on a sticker inside the driver's side door jamb or glove box. Alternatively, you can use your vehicle's VIN to look up the transmission details online or identify the transmission by its physical characteristics, like the pan shape on automatic models.
 
By checking the vehicle

• Owner's Manual: This is the most straightforward method. Look in the specifications section for the transmission model. 
• Driver's Side Door Jamb: Open the driver's door and look for a white sticker with a list of codes. You may be able to find a code starting with "M" that corresponds to the transmission. 
• Glove Box: Check inside the glove box for a similar sticker with RPO codes that can identify the transmission. 

By inspecting the transmission

• Labels and Tags: Look for a metal tag or sticker on the transmission itself. This tag will have codes that can be used to look up the specific model. 
• Stamped Codes: Check for a stamped code directly on the transmission case. These can sometimes be found next to the engine. 
• Pan Shape (automatic transmissions): The shape of the transmission's oil pan can identify the model. For example, a Turbo 350 has a square pan with one corner missing, while a Turbo 400 has a more distinctive "Texas" shape. You can also count the number of bolts on the pan for confirmation. 
• Casting Numbers: Some transmissions have identification numbers cast directly into the case. 

By using the VIN

• Decode the VIN: Use the VIN to look up the vehicle's specifications online or through a service that decodes VINs. The transmission model may be listed in the data.
• Contact a Dealership: Provide the VIN to a Chevrolet dealership, and they can look up the transmission information for you.