How-To: Install Transmission Magnetic Drain Plug and Fluid change on 2010+ Mazdaspeed3

Click on the photos below to purchase the drain plug and fluids

There have been alot of questions about the drain plug size for the MS3 but I’ve never found an answer so I figured now would be a good time to get some high performance fluid and toss in a Dimple Magnetic drain plug.

I tossed in Motul Gear 300 oil since Motul is known for making some of the best oils on the market and we’ve had awesome results especially with this gear fluid.

Here is the drain plug once you get the under panel removed from your car. You’ll need a 24mm sock and wrench to get this out. You’ll also need the 24mm to remove the fill plug.

Drain plug:

Fill Plug:

Here is the Dimple M18x1.5×12 on the left and the stock fill and drain plugs on the right and middle.

I opted to reuse the factory drain plug washer in place of the one that Dimple includes since it is much beefier.

Once the fluid is drained install the Dimple drain plug ensure you torque it down properly.

Dimple Drain Plug Socket Size is 17mm
Tightening torque
28-S0 N·m {2.9-S.1 kgf·m, 21-37 ft·lbf}

Fill the new fluid while the car is level and only fill it to the bottom of the fill hole. Torque the fill plug down reinstall your under tray and you are done.
What is really cool is you don’t need any special funnel or hoses to fill the transmission with Motul. Their bottles actually have a built in next that extends once you open the bottle and I was able to feed it to the fill hole and squeeze the fluid in very easily.

Manual transaxle oil capacity (approx.
2.4-2.6 L {2.6-2.7 US qt, 2.12-2.28 Imp qt}


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