* 4L60E: This is a four-speed automatic transmission. It's very likely the one your truck has, but not guaranteed.
* 4L65E: This is also a four-speed automatic, but generally found in heavier-duty models or those with more towing capacity.
To know for certain which transmission is in *your* specific 2004 Silverado, you need to:
* Check the VIN: Your vehicle identification number (VIN) will contain all the specifications of your truck, including the transmission type. You can use a VIN decoder online (many are free) to find this information.
* Look at the transmission itself: While this requires getting under the truck, the transmission case usually has identification markings.
* Check your owner's manual: If you still have the original owner's manual, it will specify the transmission.
Don't rely solely on assumptions based on engine size. The best and most accurate method is checking the VIN.
