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Safety First! Always use jack stands and have a back-up in case the jack stand(s) fail. Yes, the RDX has enough ground clearance where it won't kill you, but I assure you, having a 4k lb vehicle fall on your face will ruin your day.
Tools Required:
-3/8" ratchet wrench
-Stubby 17mm socket
-Flathead screwdriver (stubby preferred)
-Drain pan
-Towels
-Funnel and vinyl tubing
So, it seems the service manual calls for the entire underside cover to be removed. This is not necessary with a little bit of hill billy engineering. Anyone who has tried to do it will see that this is a chore with the amount of bolts and plastic clips that are required to be removed. It takes longer to remove the underbelly cover than the rest of the entire service. So, instead, remove the metallic cover to access the transmission. It comes off easy enough with a flathead screwdriver, four screws total and the cover slides right off. Next, you want to locate the fill plug. Always crack the fill plug on any drain and fill service. It's a tight fit, but can be accessed with a stubby 17mm socket and wratchet:
Not the best pic, but it's tight under there.
So, after you crack the fill plug (or remove it entirely), you can drain the transmission using a 3/8" socket ratchet wrench. No pictures of it, but you can view where it is in the service manual linked above. Crack the drain plug, position the pan, unscrew the drain plug, drain fluid, cuss as the fluid still splashes everywhere onto your driveway, towel up the mess. This step is obligatory and must not be skipped. Wipe off the magnetic end of the drain plug as the fluid drains. You can remove the fill plug now as well if you haven't already done so while you're down there. Replace the drain plug once draining is complete. Now comes the hack.
You mightbe able to shimmy the tubing with a hand pump up there, but those things are always a pain in the rear, at least in my experience. Even in the rear diff which is insanely easy, it's still a pain with only two quarts, let alone 5.1qts. I don't even know if it's possible, but probably.
You can purchase vinyl tubing, size: 5/8"ODx1/2"ID from your favorite hardware store in the plumbing section. Home Depot has it, but I have no stake with them and I'm sure your local hardware store will have it. This size will fit perfectly into the fill plug and allow for most funnels to fit in the other end:
Attach the funnel to the tubing and feed the other end down into the engine bay towards the fill plug area. Now go back under the car and guide it into the transmission fill. Make sure you push it all the way in with some wiggling as it may get caught on the threads. The further you push it in, the less likely it will come out during the filling process. You can cut it or leave the full length, it's up to you. I decided to cut it to make it a little easier to work with.
Topside Underside
Those of you who are astute will see the tubing in the first pic with the ratchet. I simply moved it out of the way to take the pic, hopefully it doesn't confuse anyone.
Fill the transmission with ATF 2.0. Unfortunately, seems its a dealer-only item that's pricey with no aftermarket options yet. I really don't like that its advertised to maximize fuel economy. Makes me thing that's the priority over longevity of the transmission, but I digress. Ensure you drain as much fluid out of the funnel and tubing and then remove the vinyl tubing and plug everything back up. With this, the service time should be more or less the same as an oil change.
There are other pumps out there that could do something similar, but for the cost of a funnel (few $) and tubing ($6 with some excess from H-D), you can't beat it as far as cost.
I can't take full credit. This method was introduced and used on my GTO for it's Tremec M6 transmission that made filling much easier and less messy thru another forum years back. Hopefully this can help others. Cheers.
I did this about a month ago. I didn't realize it was enough to just remove the metal plate as opposed to the whole plastic underbelly thing. This would have been useful, as it did take a lot of time, and several of the "fasteners" got chewed up in the process.
Just to be clear though, you mentioned you had issues with spillage and a mess while you were draining. Ignoring the pain of removing the whole cover for an instant.....would the draining have been cleaner if the whole belly thing was removed, or does the oil dump out the drain hole without being obstructed by that portion of the belly pan you left in place?
No, the drain plug is far back enough that once you remove the metallic cover, you have more than enough clearance for the ATF to drain freely. It just hits the pan in just the right way to create a fountain of fluid that will get everywhere but inside the pan. Of course, you could put down a towel or plastic beforehand, but that's no fun. Seriously tho, there's no obstruction once you remove the smaller panel.
No, the drain plug is far back enough that once you remove the metallic cover, you have more than enough clearance for the ATF to drain freely. It just hits the pan in just the right way to create a fountain of fluid that will get everywhere but inside the pan. Of course, you could put down a towel or plastic beforehand, but that's no fun. Seriously tho, there's no obstruction once you remove the smaller panel.
Thank you for your post, I was able to change my transmission fluid without removing engine under cover. Also was able to use my 24 teeth torque wrench by using 2.25" long 17mm socket to open/close transmission fill bolt and also 2.25" 12mm to open/close level plug.
08-27-2020, 04:32 PM
