This is not a complete DIY. For a complete DIY on how to flush your ATF fluid see this link:
Click here for a DIY ATF Flush!
This is just to highlight some changes to the 2nd gens and some 1st gens, and to also provide a couple helpful tips. My car had 43,908 kms when I performed the service.
This morning I decided to flush my OEM fluid out of my 2012 Mazda 3 with the 5 speed automatic and wanted to highlight some of the things I encountered.
To start, for those wondering I used Petrocanada's DuraDrive MV Synthetic ATF, it meets Mazda MIII and MV specs. I also quite a bi of research and found nothing but good results except for the use in Toyota WS transmissions. Some people have even used it in their Mazda's for over 80,000 km and performing absolutely fine. It costs $7.10/L and you get it in a 12x1L case from a Petrocanada Distributor. Contact PC to find one near you:
http://lubricants.petro-canada.ca/en/products/612.aspx
After putting the car on my ramps, I crawled under the car and removed the plastic shield.
The thread I highlighted above states that there is a 3/4" drain bolt on the side of the pan to drain it. On my 2012 it was an 8mm hex located in the middle of the pan:
I drained out the fluid and as you can see, the fluid was looking pretty dark:
I also took a red marker and marked off where the fluid level was on my clear drain pan. I'll explain why I did this later.
I reinstalled the drain bolt and new crush washer from Mazda. I highly recommend buying a new crush washer instead of reusing the older one. You may get leaks, it costs $1.40 for the washer from my local dealer. (May seem crazy that a single washer is $1.40, but its worth it to me instead of spending time at Home Depot looking for the right size for $0.25)
I then poured the old fluid I drained out into an old oil container and as you can see, approximately 3L drained out:
Now I know to put in exactly 3L back in as I flush. I used a simple funnel as I do not have a tranny funnel and I just removed the cover from the ECU to make it fit. Careful you do not spill any tranny fluid onto your ECU. This was a comfortable position to pour for me:
Then I crawled underneath to the tranny lines and disconnected the output line and because my local store didn't care 3/8" I.D (only O.D.) I picked up some 5/8" hose. Way too big but nothing a zip tie couldn't fix. With the clear 5/8" attached I had my girlfriend cycle through the gears and back to park until 3L drained out. This is why I made the marking I discussed earlier. When I saw the fluid approach the line I told her to shut it off to avoid running the pan dry and getting air in the lines. Getting air in the lines isn't catastrophic, but its not good for your pump.
As you can see, after I drained the first flush into another oil jug, approximately 3 litres of more tranny fluid drained out:
I did another flush and by the end you can see the fluid is now nice and red coming out:
I reattached the lines. Added my last 2.5 - 2.7 L (I didn't put the full 3L as it's best to pour to little and add more later once the car is on a level surface than it is to pour too much and overfill the tranny although the last 300-500ml is likely exactly what is needed), and ran the car to check for leaks.
After all was good I reinstalled the plastic shield and since my screws and bolts were still nice and not corroded, I applied some grease over them to keep it that way. The grease just shields them from the salt and water especially in the winter time and keeps them rust free! A little trick I've been using on my last 2 cars.
Moved the car to a level surface and checked the tranny fluid (car running in Park according to the manual) and added fluid if needed.
First test drive and it feels great. Prior to changing the fluid, my tranny still shifted fine except for a noticeable 2-1 downshift when hot. I also know the OEM fluid from the factory is of pretty poor quality.
Piece of mind knowing I have a good quality synthetic in the tranny now. I'll post back in a week once I have more driving results.
Thanks for looking.