Excess Tranny Fluid from Factory?

Hey All,

Just did my 1st tranny fluid drain & fill at 57,500 miles. I have a 2020 TRDORP. Went off without a hitch but noticed something a little strange. I positioned the truck so that my pan was level and did this first thing in the AM when things were cool. Pan temp. read 90F from my OBD scanner before draining. I cracked open the fill plug and when I cracked open the overflow next about a little less than a 1/4 of a quart of tranny fluid came out which surprised me since things were cool and I hadn’t even reached 104F. Has anyone else experienced this on their first drain and fill? I can only guess there was a little “excess” in there to begin with? All in all I drained like 3.25 quarts from the pan. I filled up with 4 qts. and after I cycled through the gears and reached 104F I wound up draining 1qt. back out. This whole setting the fluid level from how it dribbles down the overflow is so subjective. Wish there was a more precise way to refill.

On another note I was also surprised how easy it was to crack open all the bolts. Thought I’d need some PB blaster or liquid wrench to help out.

 

Smart to check the level first.

I haven't read the owners manual but multiple videos say when it starts to dribble screw the level plug back in. Like you said super subjective but the few transmissions I've changed fluid for seemed to really like to be on the high side of full. Had a BMW slipping unless it was slightly overfilled (had to jack one side of the car up higher).

Maybe toyota is doing you a solid putting in a little extra or maybe too lazy to let it get down but either way shouldn't hurt.

When I did mine, pretty much as soon as it started dribbling, well before level would be for the fluid I put the plug back in to give it slightly extra. Seems to be running well.

 

The way I measured was plugging it back up after seeing a few breaks in the steady stream. Seeing as the truck is still new-ish I also didn’t want to drain more than I first took out.

I don’t imagine you lose tranny fluid within the system barring any leaks? Similar to loss of engine oil from it getting burnt up? Still learning all this as I go along so some of that might not be phrased correctly.

 

Nope. Different kinda thing. You don't lose fluid in a transmission.

As engines wear there might be more space between their pistons which let's oil get past and into where combustion happens.

Or - if it's really cold and you start driving quickly or even during warm up oil can get past and burn up since the metal is really cold and slightly smaller so it's not sealing like it should. And also oil doesn't work or work like it should if it's cold.

 

I just did a cold drain and fill.

Put in exactly the amount I took out.

No need to hotwire the OBDII. No need to play Mortal Combat with the shifter knob. No need to overanalyze a subjective fill hole drip.

 

I just did drain & fill on 2019 with ~70K miles.

Drained 3.75qt cold.

Filled with 4qts.

Used the dash lights to tell when up to temp.

Got a small stream out overflow that ran for a bit and then started dripping. Did not drain a lot out the overflow.

So I ended up putting slightly more in than I drained out.

 

Except you don't know if it's at the correct level. Many came underfilled. Cheap infrared temp gun is all that's needed.

 

This is the way

 

Cept most aren't doing this til they rack up miles.

If you weren't worried before why worry now?

 

The hot-wire and dash lights is fairly easy to do. I documented the steps here:

https://docs.google.com/document/d/1Q7trJy3NU5dI0kF2gQA5qrAb55b8OG9LKXcmxeUPYQ8/edit?usp=sharing

It helps to go through a dry run first to make sure you understand the process before draining your transmission.

Here are also some screenshots from the manual:

 

Many coming under-filled from the factory sounds like an old wives tale. Those get perpetuated a lot around here.

How many 5th gen trans failures do you know of?

Changed mine at 75k. Now I have 116k.

Hasn't blown up yet

 

I am not worried at all-I checked the level the correct way.

 

I've seen some of those temp guns read quite a bit different than what the ECU reports. Not sure why, maybe inside oil temp vs outside pan temp?

Regardless I installed the scan gauge II for temp monitoring a while back so this was very easy to do.
Now that I've verified the level is correct I'll likely do what @nimby suggested next time.
It's a closed system so as long as I put in the amount I take out it really shouldn't be a problem.

 

Yea all the videos says if you're using a temp gun then 103/104 is good, taking it from the center of the pan - is what I did.

Edit: when procedure is between 104 and 113°F from ECU

 

FWIW answered my original question by researching more videos. Mine wasn’t filled w/ excess from the factory. You can expect a little fluid to come out of the overflow if opened before the drain when cold.

I plan to do a bit of both methods. Temp. method so that I get a feel for it and know what to expect using the amount taken out as a rough guide. I already use a scan tool on the regular and it’s a long enough interval that it’s not a big deal.

Any ideas how much can you be over or under? 1/4 qt. max?

 

I don't think anyone is going to have a good answer for that one. Don't over think it. Yolo.

 

Yup did the same. Keep it simple.

 

I don't think 1/2 qt would make a difference either way. I have seen reports of underfilled by 1-2 quarts caused strange shifting-it was fixed once the level was correct. Most put back aprox. 4 qts, do level check and 1/4 to 1/2 comes out before it dribbles.

 

Anyone notice a smoother drive after doing the ATF? Might be placebo effect but I think mine is a tad bit smoother now. Those cleaning additives at work? Didn’t think I’d notice any difference at 57k.

 

I changed mine after 60k on the he tundra and definitely got smoother especially when towing.

 

Makes me wonder if it should’ve been done sooner. Shorter thank 60k intervals? Car Care Nut says he wouldn’t do it shorter than 30k. Maybe somewhere in-between?

 

I’d do 40-60k. Wife’s 4runner just passed 50k so I’m doing it. Wouldn’t hurt since it’s on 35s haha