Transmission Temperatures

you are right, just checked my 15 cooler is there and on the 19 no cooler in sight.

 

Well...

We're probably fretting about nothing.. as much as I'd like to see a big robust B&M fan cooled ATF cooler the bottom line is performance.

I've yet to see a post by someone who pushed their rig with a heavy trailer report extreme temps or any issues. I guess we're in the first summer with a bunch of them on the road ....so we'll see.

Problem is we really can't confirm prime operating temps and how to monitor them. That was my initial query.

We KNOW what temps ATF runs best at and at what temps it starts to "burn". If this set up keeps us in that safe range... I guess I don't care.

I'll be towing my rig in a week or so through desert up mountain and at least 80° if not hotter. I'll be in and out of desert SW all summer so will find out quick!

I'll report back what Scangauge tells me...

Still curious but not overly concerned..

BTW those ATF coolers on at least 4Runners and Tacomas were very small...I was always unconvinced they did much.....Lot's of guys bypassed them to avoid "pink milk shake" and I never heard of issues.....

G

 

Does seem like it is probably a non issue. Especially for a Crewmax as one would exceed payload long before hitting max tow rating. Two adults, two kids, dog and luggage = not much payload left for trailer so less likely to push the rock solid engine and tranny to the limits.

 

Just got home from a 280 mile round trip on the interstate. Outbound the oil ran about 216 deg. at 68 mph and 58 deg. outside air. Returning it was about 220 at 76 deg. outside. Peak was 227 in the pan and 250 off the TQ converter. Pulling about 1400#. Terrain was rolling hills.
FYI,
bc

 

That seems pretty high. Did you have it in auto or manual shift mode? I found that if you put it in manual shift mode in 5th it runs cooler when towing. I think the manual says to not go above 5th when towing.

 

Here’s a good read on transmission temps. The newer transmissions along with synthetic fluid are much more capable then in the past.

http://www.rvforum.net/SMF_forum/index.php?topic=86902.0

 

Hmmm...

What gear were you in? Keep in 4th? I can't recall if OD makes trans hotter or cooler.... I recall climbing the grade from Bull Head City to Kingman in 110° summer day with my 4Runner, not towing. OD on or off either engine or trans would ramp up..

I may try another OBD device to see if same readings.


G

 

I was using sport mode and tow haul. Ran in highest gear that kept converter locked. Towed just like I did with my old rig. Either the truck is getting too hot or my guage is inaccurate. I have pulled this rig for years without trouble. 1300# is not that much for a Tundra. No way it should need 4th gear or even 5 most of the time on this route.

 

I was always told and the manual (page 187) says shift range must be 4; do NOT tow in OD.

BTW I figured but haven't determined if the Tow/Haul dis allows OD....

This was more critical with my Tacoma and 1300lbs not excessive in my book..

I NEVER tow in OD. Maybe cruising on flats but even then... I keep it 1:1 max.

BTW I'm finding threads as far back as 2016 about high TFT... 220°F+

G

 

You folks that tow heavy will be the acid test. Hope more 019ers chime in.
Thanks,
bc

 

So I finally followed the lines from the transmission "cooler" and they lead to the "engine oil cooler" pictured here.

I am baffled.....How does this system work? They have to be separate systems but share end points....It makes zero sense.... "We'll cool the transmission with hot oil....!" The thermostat has moved from the drivers side of the transmission to behind the round ATF cooler...

It's just so strange the engineers have basically hidden this information from us. I defy you to find and show me operating temperatures for transmissions for the current models..... You'd think with a towing package especially there would be warnings "stop if ATF hits 250°" and if you push it there goes the warranty.. Seems like lawyers would be pushing for such monitoring. Now we just push it till it fails....

Oh well....

G

 

That is the engine oil cooler. The black lines are coolant lines that go to the heater core and the transmission warmer/cooler and of course the radiator. My dealer has promised to get the official OK temperature limits for the new setup. Holding my breath! I plan on doing frequent drain/refills.
bc

 

The transmission thermostat was always on the passenger side as you can see if my link above. Even if 19s go to the oil cooler, at least they have one. Now you know that you can tap in to the lines and add another cooler if you want to.

I added another cooler inline on my 10 that had the factory cooler on top of the ac condensor. Didn’t really lower temps, but kept them at a more steady temp especially when towing. I didn’t get huge spikes and climbs up in temp with it added.

 

Those lines have engine coolant in them, not ATF.
bc

 

There are 4 lines. Look at the picture on page 3 of that link. From 07-18 (not sure on 19) there are 2 different parts - an ATF warmer and a thermostat. The ATF warmer (as it is called by Toyota) has 2 lines with coolant in the lines. It brings the AT up to temp faster. The thermostat has 2 lines with ATF in them. It goes to the separate ATF cooler on 07-mid 10 and to the combined ATF cooler with ac condensor on mid 10-18. It has ATF in it.

I was referencing the post above which said it moved from drivers side. It was always on the passenger side, so it didn’t move.

I think this thread is creating some misinformation. Yes, there is an AT warmer and a separate thermostat on 07-18s. Now it sounds like there is a thermostat in the 19s, it just goes to a different cooler.

 

The trans in my tundra runs 20-30 degrees warmer than my Tacoma.
Just towed 4500lbs + wind resistance on a 7ft tall enclosed yesterday in my tundra
Avg temp was 197F which matched engine temp.
Max temp was 210F off of my scanguage however I am not sure if that is pan temp or torque converter temp.
If i hit 220+ in the tundra I will investigate pinning the thermostat and/or adding an additional cooler.
The Toyota red WS fluid is not known for being the most advanced ATF.
Valvoline Maxxlife WS seems to be a good replacement for toyota WS.
I have contemplated switching but have been to nervious to perform the drain and refill myself.
I just increased drain/refill intervals when i rarely go to the dealer.

 

Hey stuckinohio, with some past trial and errors I found that pinning the thermostat open while towing reduces the overall atf temps by average of 30 degress F. There is no atf flow to the air to fluid cooler that is built in on the top of the ac condenser until the thermostat reaches about 225 minimum and 240 full flow. This applies to 2018 and previous models but there could be late 2018 exceptions, who knows.
I use Valvoline and drain 4 quarts at 60 degrees F exactly level. Measure the first time and temp. Look at my previous posts for PIDs on the pan and torq conv temps equations and someone else had posted the scangauge settings. I use a Ultra gauge.
As far as a running flush and fill the hardest part is to fill while engine running and then someone to switch into all the gears while not running dry. Leveling is done after cool down at a easy pace. Best to buy on ebay or Amazon the 18mm fitting for the fill on the transmission that comes out to a 3/8 barb to hook up a funnel and a 3/8 hose with some extra hose to be able to hold the funnel vertical by the tire and pour the atf…..

 

I'm looking for info on the why my ultra gauge isn't reading my trans temp

Does yours read it

 

Did you buy the pre programmed Toyota spec version with pan and torque converter temp or another version? If not the pids are listed on this site and must be inputted exactly as written. I can take pictures if it helps.

 

Also confirm your trans outputs the the correct signals. Ab60 etc.

 

Ok. I have no idea. If it's the Toyota spec.

It read my FJ tranny temp but reads error
On the Tundra ..

Any help would be appreciated
If you can tell me how to input the codes
And what they are I am certainly willing to try

 

2019 Toyota calls it a heat exchanger. When cold, engine coolant heats it up. When its hot coolant cools it down. I it works if you stay with in towing guidelines . To me having a temp gauge on tranny need only when your pushing the truck to or past limits. Otherwise just another gaget. Even a ford focus as a trans temp reading really ?????

 

I like to know what the temps and other workings of the car and what they normally read

I think I figured out what it's not reading

Now to figure out how to change the codes as acmesupply. Said

 

Understand ! Me the more knowledge I have I worry about it when not necessary.

 

Lol......

I am totally opposite

If I can see it I dont worry

 

Dump the ultra and scan gauges! A OBDFusion iPhone app and $10 add-on package reads the ATF. No screwing around with PIDs. A $20 OBD device and you're done. Plus you wont have ATF temps haunting your every mile!

I had a scanguage and sold it fast! PITA!

 

https://www.tundras.com/threads/ultragauge-vs-scangauge.12472/

I have a 19 and used the 2012-2015 settings. They work. Temps run high when towing like everyone is saying. It stinks.

 

I agree the bluetooth units are cheaper and more user friendly but the scangauge is still my preference. Having a dedicated digital readout that automatically boots up @start-up is convenient . No phones to mount, no apps to open don't have to flip between apps while driving. (Say you want OBD readouts and navigation).

 

using phone apps, I always manage to run out of battery on my cell ...

 

My Scanguage 2 showed temp at Torque Converter hovering around 196-215. The temp on the pan was 2-3 degrees cooler at times.