To be absolutely sure:
* Check the transmission case itself: The model number (TH700-R4 or 4L60) is usually stamped on the side of the transmission case. You might need a flashlight and possibly a mirror to see it clearly.
* Look at your vehicle's documentation: The owner's manual or build sheet (if you have one) will specify the transmission type.
* Check the VIN: A dealer or a VIN decoder website might be able to tell you the transmission based on your vehicle's VIN.
Internal Changes:
Internal changes to a TH700-R4 or 4L60 transmission are extensive and depend on the specific needs. Common upgrades and changes include:
* Hardened shafts: Replace weaker stock parts with more durable components to handle increased power or stress.
* High-performance clutches and steels: These improve shift firmness, durability, and holding power, especially useful for towing or performance modifications.
* Improved valve body: This can improve shift quality, shift speed, and potentially line pressure. A shift kit is a common modification.
* Torque converter: A higher stall speed torque converter is often used to enhance acceleration, but should be matched to the engine and intended use.
* Servicing: Replacing worn components such as seals, filters, and gaskets during a rebuild is also a common 'change'.
Before making any internal changes: It's highly recommended to have a professional transmission shop assess the condition of your transmission. Improper modifications can easily cause further damage. They can advise on the best approach based on your vehicle's condition and intended use. Simply replacing parts without proper knowledge can lead to a worse-functioning transmission.
