Last week I changed the oil and automatic transmission fluid. I drained the transmission from the plug on the pan by removing it with an 8mm torx bit, and expected to see a washer on the plug (part number 9956-21-800, a brass washer which the dealer looked up on his computer). There was no washer, the plug itself has a large flat surface like it's a built-in washer, and the brass washer described above looked to be a sloppy fit, suitable for a much larger plug.
My car is a 2006 Mazda 6 with a 4 cyl engine. I believe the 6 cylinder car uses a different transmission, so is thatwasher for the 6 cylinder car? Is there supposed to be a washer on my drain plug? Part number?
FYI, the refill is about 3 quarts for the transmission on the 4 cyl car, and the type of fluid is Mercon V. The 6 cylinder car uses a different fluid, and my advice is don't use a "compatible" fluid or one-type-fits-all. Transmissions are too expensive to take the easy way solution.

 

The 4/6 cyltransmissions are made in completely different facilities. You may possibly have the wrong seal, but it wouldn't be from the 3.0L tranny.

 

I'm wondering if there's a seal at all. The plug looks like it's a combination plug/washer. And my bad, the plug is removed with an 8mm hex (allen) wrench bit, not a torx.