A4x
04-14-2018, 08:49 PM
Overall pretty straight forward drain and re-fill. I was a little unsure of the location of the fill plug before starting this so I grabbed some pictures to help others. I suspect the procedure is the same for 6 MT transmissions.
I think the front differential is more critical to get fresh fluid into than the rear. Reason is the front shares the same housing as the transmission, also it sits right below the exhaust catalytic and downpipe. Temperatures in this region are much hotter than what the rear differential experiences. Looking at the old fluid vs new fluid, I'm glad I got this done. Just crossed over 80k miles (130 km).
Tools you'll need:
1. 8mm allen/hex bit socket + 10 inch extension to remove the fill plug. Allen key probably wont work because you need the better leverage of a bit socket to remove the plug.
2. 5mm allen/hex bit socket or hex key to remove the drain plug. Socket recommended. It needs to be shorter than about 2.5 inches or else you'll have trouble clearing the chassis crossbrace that is right under the drain plug (more on this below).
3. 10mm socket to remove fender liner nuts.
4. 1 L 75W-90 GL5 fluid (OEM part number G052145S2).
5. Fluid pump.
6. Some clean up supplies like shop towels, brake cleen to clean up the drained oil you will spill.
7. Torque wrench recommended, however I didn't use one. Fill plug spec is 27 Nm, drain plug 10 Nm.
We're going to be attacking plug #2 and 3 in this diagram,
https://i.gyazo.com/41d474d2626d71fff512c3aeae1dc3f0.png
https://i.gyazo.com/a8e9f1b07938a32d9fc5ea4daff8e582.png
Step 1: Loosen the front passenger wheel lug bolts a quarter turn. Jack up the front passenger side so that the tire is off the ground. Secure the car with a jackstand or 2, block the rear wheels from rolling and/or engage the parking brake. You will be crawling under and working in the wheel well. Remove the tire.
Step 2: Remove the 2x 10mm plastic nuts that hold this plastic fender liner support on. Then remove this plastic support altogether, it just wiggles out. Tuck the rear-most fender liner behind itself so it is out of the way.
https://i.gyazo.com/4aa164925a4306e699fd3503156016f4.png
Step 3: The fill plug is located behind the plastic piece you just removed. Use a 10 inch extension, and an 8mm allen socket to remove the fill plug. No oil will drain out. You can see the oil level sitting just at the bottom of the fill plug hole.
https://i.gyazo.com/d8b525e99e3ba03effdc0b879cda0c87.png https://i.gyazo.com/3cd898881a589609f690c21ce099badb.png
Step 4: Crawl under either from the front of the car, or from the side where the fill plug is and locate the drain plug. It is a small 5 mm plug right on the bottom of the differential housing. There is not a lot of clerance between the drain plug and the black chassis cross-member. An allen key should fit fine, and a small socket. The total height of the key or socket needs to be less than 2.5-2.75 inches. Here is mine pictured below, and it was just small enough to fit in the drain plug but I could barely get it out. Took me a few minutes of cursing to get it unstuck from the chassis cross-member support.
https://i.gyazo.com/eb7c6dc532e416c8e1c9c4da7604d2fb.png https://i.gyazo.com/b19745f226e5c22a0fe6a50abed78024.png
Step 5: Remove the drain plug and get ready for a flood of dirty gear oil. It will fall directly onto the chassis cross-member. I just let the shit flow downhill, but you might want to rig up some sort of funnel or guide ahead of time to keep the oil off the cross-member. Let it drain for a good 15 minutes then replace the plug, torque to 10 Nm.
Drain plug and fill plug side by side. Notice the black crud on the fill plug, it took some scrubbing to get it off. The drain plug also had it but was already cleaned for this picture.
https://i.gyazo.com/7fef01cac85d5d0149b7f3fa08eb0499.png
Step 6: Use a clean fluid pump to pump in 0.9 L of 75W-90 GL5 fluid. Fill until it starts draining from the fill plug. I went with OEM since I trust it is good (I believe it is made by Fuchs). You could probably easily rig up a funnel and tube setup. You just need tubing at least a few feet long to clear the obstacles in the way.
https://i.gyazo.com/7039fd58c360bb7e03ea0f3d8bc39e79.png
Step 7: Replace the fill plug and torque to 27 Nm.
Old fluid vs new fluid. Definitely time for a change (80k miles).
https://i.gyazo.com/0e636c010867d849c59a2543c59b25fa.png
Clean up any mess, replace the fender liner support and 2x 10mm nuts. Put the tire back on and lower the car. Your car will thank you for the fresh oil!
I think the front differential is more critical to get fresh fluid into than the rear. Reason is the front shares the same housing as the transmission, also it sits right below the exhaust catalytic and downpipe. Temperatures in this region are much hotter than what the rear differential experiences. Looking at the old fluid vs new fluid, I'm glad I got this done. Just crossed over 80k miles (130 km).
Tools you'll need:
1. 8mm allen/hex bit socket + 10 inch extension to remove the fill plug. Allen key probably wont work because you need the better leverage of a bit socket to remove the plug.
2. 5mm allen/hex bit socket or hex key to remove the drain plug. Socket recommended. It needs to be shorter than about 2.5 inches or else you'll have trouble clearing the chassis crossbrace that is right under the drain plug (more on this below).
3. 10mm socket to remove fender liner nuts.
4. 1 L 75W-90 GL5 fluid (OEM part number G052145S2).
5. Fluid pump.
6. Some clean up supplies like shop towels, brake cleen to clean up the drained oil you will spill.
7. Torque wrench recommended, however I didn't use one. Fill plug spec is 27 Nm, drain plug 10 Nm.
We're going to be attacking plug #2 and 3 in this diagram,
https://i.gyazo.com/41d474d2626d71fff512c3aeae1dc3f0.png
https://i.gyazo.com/a8e9f1b07938a32d9fc5ea4daff8e582.png
Step 1: Loosen the front passenger wheel lug bolts a quarter turn. Jack up the front passenger side so that the tire is off the ground. Secure the car with a jackstand or 2, block the rear wheels from rolling and/or engage the parking brake. You will be crawling under and working in the wheel well. Remove the tire.
Step 2: Remove the 2x 10mm plastic nuts that hold this plastic fender liner support on. Then remove this plastic support altogether, it just wiggles out. Tuck the rear-most fender liner behind itself so it is out of the way.
https://i.gyazo.com/4aa164925a4306e699fd3503156016f4.png
Step 3: The fill plug is located behind the plastic piece you just removed. Use a 10 inch extension, and an 8mm allen socket to remove the fill plug. No oil will drain out. You can see the oil level sitting just at the bottom of the fill plug hole.
https://i.gyazo.com/d8b525e99e3ba03effdc0b879cda0c87.png https://i.gyazo.com/3cd898881a589609f690c21ce099badb.png
Step 4: Crawl under either from the front of the car, or from the side where the fill plug is and locate the drain plug. It is a small 5 mm plug right on the bottom of the differential housing. There is not a lot of clerance between the drain plug and the black chassis cross-member. An allen key should fit fine, and a small socket. The total height of the key or socket needs to be less than 2.5-2.75 inches. Here is mine pictured below, and it was just small enough to fit in the drain plug but I could barely get it out. Took me a few minutes of cursing to get it unstuck from the chassis cross-member support.
https://i.gyazo.com/eb7c6dc532e416c8e1c9c4da7604d2fb.png https://i.gyazo.com/b19745f226e5c22a0fe6a50abed78024.png
Step 5: Remove the drain plug and get ready for a flood of dirty gear oil. It will fall directly onto the chassis cross-member. I just let the shit flow downhill, but you might want to rig up some sort of funnel or guide ahead of time to keep the oil off the cross-member. Let it drain for a good 15 minutes then replace the plug, torque to 10 Nm.
Drain plug and fill plug side by side. Notice the black crud on the fill plug, it took some scrubbing to get it off. The drain plug also had it but was already cleaned for this picture.
https://i.gyazo.com/7fef01cac85d5d0149b7f3fa08eb0499.png
Step 6: Use a clean fluid pump to pump in 0.9 L of 75W-90 GL5 fluid. Fill until it starts draining from the fill plug. I went with OEM since I trust it is good (I believe it is made by Fuchs). You could probably easily rig up a funnel and tube setup. You just need tubing at least a few feet long to clear the obstacles in the way.
https://i.gyazo.com/7039fd58c360bb7e03ea0f3d8bc39e79.png
Step 7: Replace the fill plug and torque to 27 Nm.
Old fluid vs new fluid. Definitely time for a change (80k miles).
https://i.gyazo.com/0e636c010867d849c59a2543c59b25fa.png
Clean up any mess, replace the fender liner support and 2x 10mm nuts. Put the tire back on and lower the car. Your car will thank you for the fresh oil!