Yes, the engine must be running.

Doing a pan drop and refill, how many quarts are you using? Since this stuff is only available at the dealer, I'd like to have enough on hand before starting this project.

I would buy at least 5 qts.

Great information. I'm unread with regard to the transmission fluid change and all that is associated with getting it right or wrong, so I apologize in advance if this question is obvious.

Is there a clear definition of what temperature is the right temp for fluid to begin to exit the overflow hole? Reason I ask is "operating temperature" of my transmission as revealed via Scangauge seems to vary widely. I've seen it as high as 180 and on cooler days be in the 120-130 degree range. As we go into the cooler season it might even be lower. I would imagine this line on the graph would stay linear and therefore the fluid would continue to rise as temperature of the transmission rises, thus my confusion about what temperature to validate the overflow hole at and/or what is considered "operating temperature".

Not exactly sure what you're asking but the temperature range targeted for checking the transmission fluid level is 97-115F.

If you pulled the overflow plug when the fluid was hotter than that, yes, too much would flow out.

For the most part, if you simply drive the truck until the engine coolant comes completely up to full operating temp and then let the truck idle and pull the overflow plug, everything takes care of itself as the transmission fluid should be very close to the lower end of the 97-115F range at that point.

Not a bad idea to let the truck idle for an 5 extra minutes or so, for good measure, and that gives you time to move the shifter through the gear range.

That's exactly what I'm wondering. Is it standard operating procedure to pull the overflow plug or are people only doing this because the fluid level on the dipstick is too high and this is the best option to remove excess?

There is no Dipstick on the "Sealed" WS ATF transmissions on 4Runners. The Overflow Plug is more accurately referred to as the "Inspection Plug" and has a calibrated tube that you use to determine the fluid level at a given temperature.

Checking it when it is too cold or too hot will yield an incorrect fluid level reading and thus skew your results. It should always be checked at the appropriate temperature range and after running the transmission through all its gears.

Umm... I have a red handled dipstick for the transmission right next to the yellow handled oil dipstick... 03 V8. Not sure what transmission we're talking about here. Since the OP has a V8, I assumed they were all the same. Was the dipstick removed on later models?

Correct. 03's have a dipstick. Later the transmissions were "sealed"

As was pointed out, '03 2UZ-FE Equipped V8's had a traditional dipstick equipped transmission that uses Type IV ATF, as did '03 & some '04 1GR-FE equipped V6 4Runners until they became standard with WS ATF "Sealed" Transmissions.

Ahh. All this makes quite a bit more sense now. Thanks.

Have you ever done the temp check mode at the same time to compare both methods?

Yes, that's exactly what this thread is about.

See first sentence of first post.

Apologies for the thread archaeology here...

Have owned my 05 Limited from new and it's just 500 miles short of 200k. Yesterday driving home it refused to shift past 3rd gear. The tranny has been a bit wonky for a while, not engaging immediately at starts, not releasing at stops.

It's entirely possible that I stupidly emptied some of the fluid during a recent oil change in a dark, cold garage, so I'm going to see about topping it off tonight in hopes of reviving 4th and 5th gears.

It seems like the general procedure is:

1. Open the overflow plug and add fluid through the fill plug until it dribbles out the overfill.
2. Close overflow and fill plugs.
3. Drive slowly around neighborhood to bring it up to operating coolant temp.
4. While still with the engine running, move shifter through all the gears several times.
5. Let idle five more minutes.
6. Open overflow and let excess run out until stream breaks.

I'm thinking #5 is done with the engine OFF, but that's not specified here.

Appreciate the knowledge here, and welcome input.

Indyota Jones, Thread Archeologist

To follow up for any future finders of the thread:

I had to repeat the process twice, as the first time nothing came out of the overflow after I removed the plug.

Also, the fill plug is high on the passenger side of the transmission at the rear, near the transfer case. You'll need a 24mm standard (non-deep) socket for it.

I now have all five forward gears, which is helpful on the rare occasion we get to the speed limit on the freeways around Seattle.

Thanks to all who contributed to this post...it saved me $500 at the tranny shop and a two week wait.