2011 CX-9 Sealed Transmission Service

2006 Mazdaspeed6
Hello all,

I've purchased a used 2011 CX-9 a few months ago with just over 100k. I couldn't find any record of the transmission being serviced and park-to-drive isn't as smooth as I think it should be.

I'd like to go ahead and service the tranny as I typically do for all my other cars. That is; drain, remove/clean pan, replace filter, fill, then proceed to flush out old fluid still in the torque converter by running the engine and capturing/replenishing dirty fluid in intervals one quart at a time from the transmission cooler hose.

Since this is a "sealed" transmission, things are a little different and I'm having trouble finding reliable information.

I have already done searches and haven't come up with the specific info I'm looking for. Any help is greatly appreciated.

-First; Does this car have a replaceable transmission filter accessible via the pan?

-Second; I have found that the transmission drain actually has a removable overflow fill plug. Obviously the best method is to replace fluid with the exact amount that was removed. However, this gets tricky especially when removing the pan. Can the fill plug be used to top off the transmission with the correct fluid level? Recall there is no dipstick on this car. I assume that's what the drain plug is for but would like some confirmation. If so, do I top off with the engine running as normal or with the engine off?

-Third; From what I've read it seems capacity is 7 quarts. Is that just the drain and fill volume or the total fluid in the transmission? Anybody have experience doing a flush as described above and if so, how much fluid did you go through?

Any other tips or lessons learned with this job would be great.

Thanks in advance.


2011 BMW 528i, 2015 Mazda 6, 1995 Nissan Maxima Manual
Im pretty sure the filter is somewhere in the pan or in the valve body

7 quarts is probably the total capacity, you will remove less from initial drain and fill

Use redline transmission fluid

Replace shift solenoids and valve body while youre in there

Ensure the new pan is properly sealed with a gasket

When draining the fluid, just drop the pan. It will be faster and easier vs draining through the hole.

When adding new fluid, keep filling until some fluid comes out the hole indicating its full.

Go got a drive after to mix fluid in the torque converter and then do one more drain and fill.
2006 Mazdaspeed6
There are a few threads on this subject. Here is one I participated in: https://www.mazdas247.com/forum/sho...luid-Changes&p=6326764&highlight=#post6326764

I am not aware of any accessible transmission filter. There is a pan on the front side of the transmission but from everything I have seen it just houses the valve body. Hope this helps.


Thanks Charles. Your write up there was pretty helpful. I don't see anyone anywhere discussing changing the filter or using the flush method. Guess I'll just do a drain and fill and maybe a subsequent one soon after depending on how burnt the tranny fluid looks.