How to Identify a Chevy Automatic Transmission

by Cameron Easey

Chevrolet transmissions can be manual or automatic. Automatic transmission on a Chevy can be identified in one of two ways: You can look at the size of the pan on the transmission or you can search for the identification number that has been stamped somewhere on the casing. To undertake either method will require you to look under the vehicle.

Move the vehicle to a flat area where you can work, such as your garage.

Raise the front of the vehicle off the ground with a car jack. Lift the driver's side, then place a jack stand under the frame behind the front wheel and lower the driver's side of the car onto the jack stand. Repeat this procedure for the passenger side of the Chevrolet.

Slide on your back (or on a creeper) under the front of the vehicle.

Locate the transmission, attached to the back of the engine. Look at the shape of the pan and compare it to diagrams to determine the type of transmission that is on your vehicle See the GM Transmission Identification & Decoding link in Resources below.

Locate the "source serial number" that is stamped on the transmission. The source serial number location is typically found on the driver's side of the transmission on most Chevy vehicles.

Write this number down on a piece of paper with a pencil.

Compare the source serial number with a list of transmission types based on the RPO number. RPO stands for Regular Production Option which is used on GM parts such as the transmission.

Tip

  • check The RPO number on the transmission begins with the letter "M."

Warning

  • close Do not get under the vehicle without first setting the jack stands under the frame of the vehicle and lowering the vehicle onto the stands.

Items you will need

About the Author

Cameron Easey has over 15 years customer service experience, with eight of those years in the insurance industry. He has earned various designations from organizations like the Insurance Institute of America and LOMA. Easey earned his Bachelor of Arts degree in political science and history from Western Michigan University.

Photo Credits

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