Changing your automatic transmission fluid (ATF) and transmission filter is important to keep your drivetrain smooth. While performing this service isn’t technically hard, filling the transmission fluid to the precise level is difficult without some experience. Therefore, we do not advise you attempt to do-it-yourself unless you are comfortable working on cars.
Even if you don’t feel comfortable performing this service yourself, you can still save a bunch of money by purchasing the parts required online and paying an independent mechanic for just the labor. For an overview of the procedure, check out the procedure from the YouTube channel, Road and Race. While the video covers the procedure on a Porsche 986 Boxster, the process is nearly identical for the 996. You can find detailed instructions below.
Tools Required:
- Mechanic’s Tool Set
- Torx Bit Socket Set, T10-T60
- Metric Hex Bit Socket Set, 3mm to 10mm
- Etekcity Lasergrip 774 Digital Infrared Thermometer (to measure ATF temperature)
- 3/8 Inch Drive Click Torque Wrench (10-80 ft.-lb.)
- 1/4 Inch Drive Click Torque Wrench (20-200 in.-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, 16 Quarts Capacity
- Fluid Transfer Pump Kit
- Disposable Gloves
- Safety Glasses
Parts Required:
Torque Specs & Fluid Capacities:
ATF Capacity: 4.5 liters (measured when ATF is between 86-104°F)
Fill Plug (6mm hex bit): 15 ft-lbs
Drain Plug (6mm hex bit): 15 ft-lbs
Transmission Oil Pan Bolts: 6 ft-lbs
Transmission filter bolts: 4.5 ft-lbs
Aluminum crossmember bolts: 48 ft-lbs
Step-by-Step Instructions:
Step 1: Prepare your vehicle and work area
- Start with a cold engine.
- 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: Gain access to the transmission oil pan
- Remove the underbody panels on the bottom of vehicle and just ahead of the engine; these are just held on by Phillips screws and 10mm plastic nuts.
- To gain access to the transmission oil pan, you will need to remove the aluminum crossmember; remove the 15mm bolts that hold it in place.
- You should now have access to the transmission oil pan.
Step 4: Remove the transmission oil pan fill plug
- Locate the fill plug, which is located on the angled portion of the transmission oil pan.
- Break the fill plug loose with a 6mm hex bit and ratchet. Do not fully remove the fill plug.
- Place a drain pan under the fill plug in case ATF comes out, then remove the fill plug.
- Note: If you cannot get the fill bolt off, STOP and do not proceed with the procedure as you will not be able to fill your transmission with new ATF.
Step 5: Drain the automatic transmission fluid
- For an overview, check out the video from Prime Technology; while the video is for a 997, it also applies to the 996.
- Locate the drain plug located on the bottom of the transmission oil pan.
- Break the drain plug loose using a 6mm hex bit socket and ratchet, but don’t fully remove it.
- Place a drain pan underneath the drain plug, then remove the drain plug; be sure to catch the drain plug so it doesn’t fall into the drain pan.
- Clean off the drain plug threads, reinstall the drain plug, and torque it to 15 ft-lbs.
- Note: Porsche states to use a new sealing ring, however, one may have never been used from the factory. It is a good idea to purchase the crush washer assortment kit listed in the parts section in case your car does use a sealing ring.
Step 6: Remove the transmission oil pan
- Place drain pan below the transmission oil pan.
- While supporting the transmission oil pan (to avoid damaging anything), remove the six T30 Torx bolts that hold the transmission oil pan in place.
- Carefully pull off the transmission oil pan and watch out for any ATF that comes out.
- Inspect the mating surface where the transmission oil pan and transmission meet; if there is any residue or leftover gasket material, clean it off.
- With the transmission oil pan off, take a look at the fill plug baffle so you will be able to route your fluid pump hose through it accordingly.
- Clean the transmission oil pan thoroughly with a degreaser, then dry it off.
Step 7: Install the new transmission filter
- The transmission filter is held on by T30 Torx bolts.
- Remove these bolts, then pull out the old transmission filter.
- Pour any fluid inside the transmission filter into your drain pan.
- Apply a thin layer of new ATF onto the rubber seal on the transmission filter to help it seat properly.
- Install the new transmission filter and torque the bolts to 4.5 ft-lbs.
Step 8: Reinstall the transmission oil pan
- Place your new gasket on the transmission oil pan.
- Install the new gasket and transmission oil pan back onto the transmission.
- Screw in the six T30 Torx bolts by hand, but don’t tighten them.
- To ensure the transmission oil pan is seated properly, in a criss-cross pattern, torque the six T30 Torx bolts to 4.5 ft-lbs.
- DO NOT over-tighten the bolts or the gasket may leak.
Step 9: Fill the transmission with an initial amount of fresh ATF
- As shown in the video from BleeinJeep, attach the fluid pump to your container of ATF and route the other hose into the transmission oil pan fill hole; be sure to route the hose through the internal baffle or you will not be able to get the new ATF into the pan.
- Pump new ATF fluid into the transmission until fluid begins to drip out of the fill port.
Step 10: Add additional ATF and ensure you reach the correct level
- To ensure the ATF is at the correct level, your vehicle must be level and the ATF level must be measured once the fluid reaches between 86-104°F (30-40°C).
- With the brakes engaged, start your car and cycle the transmission from PARK to DRIVE and then REVERSE. Pause in each gear for 10 seconds.
- Go back under the car and add more ATF if fluid isn’t dripping out.
- Once fluid is dripping out, use a pyrometer to measure the temperature of the oil pan.
- When the transmission oil pan reaches the target temperature and ATF is barely dribbling out, you’ve reached the right level.
- Before the transmission oil pan reaches 104°F (40°C), reinstall the fill plug along with a new o-ring and torque it to 15 ft-lbs.
- Note: If the ATF pan exceeds the target temperature, install the drain plug, turn off the engine, and allow the ATF to cool back down.
Step 11: Reinstall everything and lower your vehicle
- Reinstall everything in reverse.
- Torque the 15mm bolts that hold the aluminum crossmember to 48 ft-lbs.
- Just hand tighten the fasteners for the underbody panels.
- Lower your vehicle.
- Save your old ATF in a contain, so you can drop it at your local auto parts store to recycle.
- Clean up your work area and put away your tools.
Andy says:
I have a 2002 Carrera C2. I had read in some magazine a while back that the Drain Plug should be torqued to 29 ft-lbs and the fill plug torqued to 59 ft-lbs which seemed extreme. Can you please confirm that 15 ft-lbs is the correct torque spec for both? This would be my first time changing the ATF and I am just want to get it correct.
I appreciate any input.
Thank you,
Andy
ecarguidesllc says:
Hi Andy. Does your ATF transmission pan look like the one in this video? If it does, then 15 ft-lbs is indeed the correct torque specs for both the drain and fill plugs. However, if your drain pan looks like the one in the initial video of the Boxster, than you want to torque the drain plug to 30 ft-lbs and the fill plug to 59 ft-lbs. Hope this helps.
Andy says:
Thank you so much for the information. My pan looks like the one in the video, not the Boxster.
I appreciate all your help.
Thanks Again,
Andy
Michael Higgins says:
Excellent Article –Easy to do –especially on a ramp–here in Galway Ireland -dealing with 2001 996C4 with 60K Kilometers LHD car like new -first oil change on transmission & front differential Michael