I strongly recommend taking your vehicle to a qualified transmission specialist or mechanic. They have the experience, tools, and knowledge to do this correctly.
However, if you're determined to attempt this yourself, be aware of the following general steps. These steps are simplified and may vary slightly depending on your specific transmission type (e.g., 47RE, 48RE). Always consult a repair manual specific to your vehicle's transmission for detailed instructions and torque specifications.
General Steps (Highly Simplified):
1. Safety First: Disconnect the negative battery cable. Support the vehicle securely on jack stands. Wear safety glasses and gloves.
2. Drain Transmission Fluid: Completely drain the transmission fluid using the drain plug.
3. Remove Transmission: This is the most challenging part. You'll likely need to disconnect various components connected to the transmission (driveshafts, cooling lines, electrical connectors, etc.). You'll almost certainly need a transmission jack to safely lower and support the transmission.
4. Disassemble the Transmission: This requires removing the valve body, separating the transmission case, and accessing the pump itself. You will need specialized tools to carefully disassemble the transmission without causing damage. This often involves removing various clutches, bands, and other internal components. Refer to a detailed transmission repair manual for precise disassembly procedures.
5. Replace the Oil Pump: Once the transmission is disassembled, you can remove the old pump and install the new one. Ensure the new pump is properly seated and aligned.
6. Reassemble the Transmission: Carefully reassemble the transmission, paying close attention to the correct placement of all parts. Use new gaskets and seals as needed.
7. Reinstall the Transmission: Carefully reinstall the transmission, making sure all connections are properly made.
8. Refill Transmission Fluid: Fill the transmission with the correct type and amount of fluid as specified in your owner's manual or repair manual. You may need to use a transmission fluid measuring tool to get the correct level.
9. Check for Leaks: Check for any leaks after reinstalling the transmission.
10. Test Drive: After completing the repair, test drive the vehicle to ensure the transmission is functioning correctly.
Tools You'll Likely Need:
* Transmission Jack
* Various Sockets and Wrenches
* Torque Wrench
* Transmission Repair Manual (Specific to your vehicle's transmission)
* Pry Bars
* Seal Installation Tools
* Drain Pan
* New Transmission Fluid (correct type and amount)
* New Gaskets and Seals
Again, I cannot stress this enough: This is a complex repair. Unless you have extensive experience working on transmissions, it's best to leave this job to a professional. A mistake could lead to expensive repairs or even irreversible damage to your transmission. A repair manual specific to your transmission is absolutely crucial.
