There might be a better way to do this, but this is what I did.
*** Use this at your own risk ***
1) We need to raise both the front and rear of the car so it is level and off the ground. I started with the rear. My car is too low for the jack to fit under the sub-frame and have room to move the handle. I used the stock jack at the stock jack location for the rear to get the car up a bit more.
2) Jack the rear up from the sub-frame, do NOT use the diff. Also be sure you don’t put the jack under that aluminum drive shaft thing. I double check that I have the jack pad in the right place before putting any weight on the jack.
3) Support the rear on jack stands. I used cement blocks under the stock rear jack points. Using cement blocks is not as safe, if you do use blocks make sure you have them with the open side up as they are strongest that way.
7) I used a section of old cardboard to lay on (doesn’t hurt your back as much) and slid under the car. Locate both the drain plug (on the bottom – picture below) and fill plug (on the passenger side up about 6 inches on the transmission). Mine were stuck so I sprayed some PB Blaster on them.
10) While the fluid is draining we will setup our fill ‘device’. As you will have noticed there isn’t enough space to simply pour the fluid into the transmission. Lucky for me the Royal Purple Synchromax comes in a cool squeeze bottle. I rigged up 3 feet of tubing right into the fill hole on the tranny. You can see the clear plastic tube zip tied to the exhaust in this picture.
11) Here is the rest of my rigged up fill tube. The yellow cap is off one of the Royal Purple bottles. The tube is jammed on the cap and zip tied for good measure. If you’re wondering what the hell I’m doing, that is OK, I was thinking the same thing at this point.
12) I left the drain plug out and squeezed some fluid into the transmission. My hope was to flush out any residue or other junk that might be still sitting inside. Not sure if it worked or not but it didn’t hurt.
13) With that done I cleaned and put the drain plug back in. As you are tightening a steel plug into an aluminum housing you want to be careful with the torque. I used my torque wrench to be safe. Tighten to 44lbs-ft (I think).
14) With the drain plug back in we can now fill up the transmission. You fill the transmission until the fluid is level with the bottom of the fill hole (this is why the car needs to be raised both front and back so it is level). I used my fill tube rig to fill up the transmission until it leaked out the fill hole.
15) With the transmission full, clean and reinstall the fill plug and torque to 44lbs-ft (I think).
16) I sprayed the transmission off with a bit of brake cleaner to remove the fluid that leaked out of the drain hole.
17) Lower your car off the block by reversing what you did in the first few steps.
18) Go for a drive and appreciate the improved gear box feel!
Writeup by: tim330i