Transmission fluid level confusion

I have a used 2006 Toyota Highlander 3.3L V6 (3MZ-FE engine) AWD with automatic transmission. I just changed the transmission fluid as I was not sure when the previous owner last changed it. I drained the transmission fluid only (did not replace transmission filter). I measured the amount of old ATF that came out and measured approximately 5.2L (5.5 US quarts). Most websites say a refill without filter replacement takes only 3.5L (3.7 US quarts). I added 4L (4.2 US quarts) as I figured over-filling by 500mL shouldn’t damage anything. I drove around for 20 minutes and parked on level ground to check the transmission fluid dipstick while the engine was running. Surprisingly, the level on the dipstick was too low (I’ve attached an image below to show the approximate fluid level when I checked it with a red arrow). I’m baffled on why it’s reading low. I have the same dipstick on my Toyota Corolla and never have this problem when I change my transmission fluid. It always reads where it should be when I check it. Maybe the Highlander needs more than 3.7 quarts or perhaps the dipstick is wrong? Any thoughts would be appreciated. Thanks


Why is this confusing? You drained 5.5 quarts out and only put 4.2 in. That says to me you are 1.3 quarts low assuming the trans wasn’t overfilled to begin with. Add at least another 1/2 quart and measure again. Repeat until you reach the proper level.

Don’t overthink this.


This is true. Always use the dipstick and correct measuring procedure to fill transmission. Just curious why did you not replace the filter also?

Probably because you have to drop the pan and Toyota (my 2013 at least) still has a drain plug on the transmission pan. Much easier to just drain and fill with the drain plug than drop the pan and change the filter. Yes, I know. It would be better to change the filter. I haven’t done it on our Toyota either, although I’ve changed the fluid twice. I guess I’m partially lazy. :grin:

I halfway wonder if by the time the filter actually clogs with clutch material and debris if your trans isn’t done anyway.

I did not replace the filter because one of the transmission pan bolts was stripped. I will be replacing the filter at next change.

It’s confusing to me that 5.5 quarts drained out, when every website and manual says a refill without filter change takes 3.7 quarts. That makes me think that it’s overfilled by 1.8 quarts, however, that is not reflecting on the dipstick. I’ve read that it’s not good to overfill an automatic transmission.

Do you believe the dipstick?

@Ross85 what you have in front of you is real life. The manuals are a guide. The real life definitive answer is the dipstick.

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I usually measure what comes out when I drain the transmission. An old empty 5 qt oil bottle works well. If I measure about 4.5 quarts came out, and I put 4.5 quarts back in, and the dipstick agrees by showing the proper level….then for one brief shining moment, all is right with the world.

The AT in a 4 cylinder Corolla takes 3.5 qt when just using the drain plug, 4.1 qt after dropping and cleaning the pan. I think you better use the full 5.5 qts.

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A slight overfill of the transmission fluid will hurt nothing.
Running it a quart or two down can.


I have 73K on my 2015 rav. changed trans fluid about 10 or 11X so far. Once (low 60K area) I changed the filter. About 2.6 qts come out from the drain plug. When I dropped the filter, more came out (about 3.6 qts total now). I saw yesterday that my trans was 3.2L on a service (assuming service means filter too) and 6.5 qts total. So it makes sense more fluid comes out with the filter. Not sure what your highlander Vt is.

Seriously ? That is about every 7300 miles . Talk about overkill :astonished:

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This link isn’t directly applicable to OP’s vehicle, but may still be of help.