Changing your manual transmission fluid is important to keep your transmission healthy and shifts smooth. Over time, the oil loses its critical properties that prevent metal on metal contact. This is a easy do-it-yourself as long as you have the proper tools and ability to get your vehicle off the ground safely. If you are unsure, please visit a certified mechanic.
Before you get started, check out the video from Ovalbore to get an overview. While this video covers the 997 generation specifically, the procedure is very similar for the 991 generation. Detailed step-by-step instructions can be found below.
- Mechanic’s Tool Set
- Metric Hex Bit Socket Set, 3mm to 10mm
- 3/8 Inch Drive Click Torque Wrench (10-80 ft.-lb.)
- K Tool International Low Profile Jack (3.33 Ton)
- ESCO 10499 Low Profile Flat Top Jack Stands (Pair) (4 required)
- Wheel Chocks
- Oil Drain Pan, 6 Quarts Capacity
- Fluid Transfer Pump Kit
- Disposable Gloves
- Safety Glasses
Manual transmission oil capacity: 2.7 liters
Oil fill plug (10mm hex): 22 ft-lbs
Oil drain plug (10mm hex): 22 ft-lbs
Step 1: Prepare your vehicle and work area
- Starting with a cold engine, drive your car lightly for 5 minutes to get the drivetrain fluid warmed up; this will make it easier to drain the differential fluid.
- Park your car on a flat surface.
- Gather required tools and parts.
- Put on gloves and eye protection.
Step 2: Raise your vehicle off the ground
- To give yourself enough clearance to work, safely raise your vehicle using a lift or jack and jack stands.
- ENSURE YOUR CAR IS LEVEL! This is essential to ensure the correct fluid level.
- NEVER rely on a jack to keep your car up; use jack stands to safely support your vehicle.
- Also be sure to use wheel chocks to prevent your car from rolling.
- To lift your vehicle on jack stands, check out this helpful video from CarFanatic.
- While it is for the Porsche 997, the procedure for the 996 is the same.
- Once your car is on jack stands, give your car a hard shove to make sure it is secure.
Step 3: Remove the manual transmission fill plug
- Locate the fill plug, which is on the driver’s side of the transmission and in front of the rear axle.
- Use a 10mm hex bit socket to remove the fill plug.
- If you cannot remove the fill plug, STOP AND DO NOT PROCEED as you will not be able to add new oil.
Step 4: Drain the manual transmission oil
- Locate the drain plug, which is on the bottom of the transmission.
- Use a 10mm hex bit socket to break the drain plug loose, but do not fully remove it.
- Position an oil catch pan underneath the drain plug, then remove the drain plug. Make sure to catch it before it falls into the oil catch pan.
- Let the oil drain for at least 15 minutes.
- Clean the drain plug threads, then reinstall the drain plug along with a new sealing ring and torque it to 22 ft-lbs with a torque wrench.
Step 5: Fill the manual transmission with new oil
- Note: Before filling the transmission, make sure the vehicle is level so you can fill the oil to the correct level.
- As shown in this video from BleeingJeep, use a fluid transfer pump to add ~2.7 liters of new oil to the transmission.
- Once oil begins to drip out of the fill hole, you’ve reached the correct oil level.
Step 6: Reinstall the transmission oil fill plug
- Clean the fill plug threads and reinstall the fill plug along with a new sealing ring.
- Torque the fill plug to 22 ft-lbs with a torque wrench.
- Ensure there are no fluid leaks.
Step 7: Lower your vehicle back on the ground
- Lower your vehicle back on the ground.
- Clean up your work area and put away your tools.
- Save the used oil in a container, so you can recycle it at your local auto parts store.