ATF Temperature for Level Check?

Howdy,

Did a flush and fill on my 2013 TRD 4x4 today. I swore I read temp had to be between 113° and 119° and when double checking found a LOT of various temperatures.

Some being a max of 113° and others the 119°

6° shouldn't be that much of an issue but ...... since I want to do this just once.

Please clarify,

Thanks,

W

 

https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/

 

Yea,

This uses the jumper wire method. I have an OBD that gives temperature and much easier IF I can get the actual temperature confirmed.

Maybe I was jettisoned into the 3rd gen forum but I have been seeing a variety of temperatures in the threads.

Thanks though!

W

 

Wish I could help more. No idea about correct temp.

 

I thought 115° but I think anything in that area will be fine. Don't overthink it. It's not THAT critical.

 

well the thread from post#2 says

 

I found a page from a manual that says that too. Attached it here.

Clearly read other threads that say 96° so that makes it a 40° swing....

But yea, not gonna over think it. Mine was 119° which seems to be the idling temp as it peaked there for ~10 minutes as I checked, added then rechecked.

Thanks,

W

 

Nothing could be simpler than the paper clip method. The vehicles internal system will let you know when it's time to pull the overfill plug.

 

Don't really understand why factory can take something simple and make it hard...Should just be like a differential check.. Should come out of overflow at full operating temperature..

 

Well it "seems" 113° to 119° IS a typical operating temperature. Took about 15 minutes to reach 113° then the temperature lingered in this window for a good 15 minutes. Could have been longer but I was done...

Average AZ day of 70°-75°

As per wire technique, that just sounds incredibly hit or miss.....

Thanks,

W

 

If you want better accuracy, get a Scanguage. That is what I used.

 

I can't determine for sure if Scan Gauge reads ATF temps on a 2013. I used OBDFusion and and user defined PID that reads pan temps.

I'd like a scan gauge for other reasons though! Obviously it works for you. Did it do so out of the box or was there user added PID's as with iPhone type apps?

Thanks,

W

 

I do not believe that anything changed from 2013 to 2015 so it should work on your truck. I did have to enter a code on the scanguage in order to monitor the ATF fluid temperature. I believe that I found the code here on TW.

 

Yup I'm a big proponent of doing it with a jumper wire like the FSM says.

But after I've seen guys on this forum do all sorts of stupid things to their trucks, I don't know if I would recommend any of them do it this way. LOL.

 

I know this thread is a bit old. I did just find this info.

http://www.ttguide.net/adjustment-932.html#:~:text=(Recommended ATF temperature: 35°,95°F) or less)

NOTICE:

• If the fluid temperature is below 45°C (113°F), proceed to the next step. (Recommended ATF temperature: 35°C (95°F) or less)
• If the fluid temperature is 45°C (113°F) or more, turn the ignition switch off and wait until the fluid temperature drops below 45°C (113°F).

This guide is for 2015-2018 so it covers 2nd/3rd gen. The last time I worked on the trans I believe I went to 119f. The resource I posted here says do not go over 113f and that 95f is optimal.
So...ummm. why so many different numbers lol. I guess I will go with 115f.

 

The fill procedure works with fluid expansion . 15 to 20 degrees does not make that much difference . As long as the fluid trickles out the overflow while warm is by far the most important step . New transmission fluid has re-agents just in case you accidently overfill .Some shops that repair these transmissions purposely overfill because they believe that the overflow was engineered too low . There are no re-agents on the market to assist with an underfilled transmission .

 

Good points! I feel like after i refill the trans pan it all comes back out when i pop the overflow plug. So maybe it is off?
Could you explain what reagent is and how that helps if you fill the trans too much?

 

Is your truck running when you pop the overflow plug ?
Re -agents are the additives that are placed in new transmission fluid . Re-agent depletion is the reason we change the fluid . After many heat cycles , the re-agents in your fluid diminish completely . Even when The colour of the fluid still looks good, your additives can be completely gone . Just because Toyota says the fluid needs to be replaced at 60K , its up to you as the owner to decide if the fluid should be changed out sooner than the 60k rule .If you are towing or in stop and go traffic or 4x4 low on a constant basis , the additives in your fluid are going to diminish quickly . A lot of members watch their transmission temps as well as add a transmission cooler in an effort to keep their transmission fluid cool ,in good condition and prevent the fluid from overheating . Heat kills the additives .
There are anti-foaming additives as well as demulsifiers added to new transmission fluid to assist with an overfill condition . There are ZERO additives in new transmission fluid to assist with an underfilled transmission. In other words , make sure the trans is properly filled

 

No my truck is off when I do any work on it. I got it to 113 degrees this last time per the ScanG and I do watch the temps each and every day while I am driving. Usually sits around 185-195 consistently. Every time I have done a trans pan fluid exchange the fluid is bright red when it comes out and there is no burnt smell so I feel like it is holding up to the tasks I am asking of it. I usually go into 4x4 10 times a month and 4LO once or twice a month. Shifting all feels great, no strange noises, and the temp stays at a good constant temperature. I am confident I have the right level of fluid in the trans.
I really appreciate you explaining what all is in the trans fluid and how that interacts with our transmissions. A day that I learn something (which is every day) is a good day!
You take care and have a Happy Thanksgiving!!

 

Just to confirm , your engine needs to be running when you pop the overflow plug . The engine drives the transmission pump . The transmission pump charges the torque converter and hydraulic circuits . As soon as you shut the truck off , the transmission pump stops charging the torque converter and hydraulic circuits and all that fluid drains back to the transmission pan . If you pop the overflow plug with the truck off , the transmission will drain a lot of fluid . You will be incredibly low on trans fluid if you are checking for level with the truck off .
If you check it with the truck running , disregard the above