2019 tundra transmission thermostat location

Why all the different warmers on Toyotas? Mine has the 2 lines coming out of the trans to the warmer. Along with the 2 larger coolant lines. The new tundras don't have the lines coming out of the trans to the warmer. Must have ports machined into the spacer between the trans and warmer that o ring seal against the trans. Maybe to keep people from easily installing an aux cooler.

 

It looks like you have the thermostat, just that the lines are sealed off with those metal square blocks. You could probably run an aftermarket cooler.

 

Mine doesn't have the thermostat.

 

mine looks just like this one

 

Your illustration is for the 5.7L A60 transmission. @Ghost23 has a 4.6L with the A760 transmission with threaded elbow fluid connections (circled red below) and rubber hoses to the warmer-cooler. There is no thermostat in @Ghost23 photo. There is an adapter plate (circled blue below) between transmission and warmer cooler. The A760 transmission has more flexibilty for elimination of the warmer-cooler if the owner desires.

The A760 is apparently an older design than the A60. The A60 was designed from the beginning for installation of warmer-cooler and thermostat. It has machined flat surfaces on the transmission case for o-ring sealing of a spacer or thermostat that bolts directly to the transmission case. The use of threaded elbow fluid connections go back to when Toyota first added external coolers, and those did not have thermostatic control.

 

Same problems here, jut got my 2020 Sr5 4x4 last week and using to move now. Very disappointing. I am not wanting to void my warranty but it may be necessary to not toast my new truck. Temps are 240-260 Pan and 230+ on the other. Been towing a 7x16ft trailer moving probably easy loaded to 8k+.

 

The hoses with the red circle looked like the thermostat to me, just closed off. I’ve never had a 4.6 so didn’t know what that trans looked like exactly.

 

What are the threaded elbow fluid connections for? Just wondering. Looks like they are supposed to go to something if not a cooler. What flows through them? Is it for drain and fills?

 

As I said, the elbow fluid connections were added by Toyota years ago to provide an external transmission cooler, back in maybe Gen 1(?). I don't know the exact year, but if you follow the parts history on TOCS site you can see where they began. When the warmer was added, the elbow/hose connections were simply made to either the adapter plate (no tow package), or the thermostat, which replaces the adapter plate (tow package 2010-2013).

Yes, I hadn't thought of it, but disconnecting the return hose from the warmer cooler would permit a full fluid exchange same as the video covers for the 5.7L. Simple drain and fill would still be handled the same way as all Tundras. Only difficulty I see for the full fluid exchange is that the hose from warmer to elbow is very short, inflexible, and will be difficult to remove with the warmer-cooler in position. When I retrofit the external cooler to my 2017, I plan to unbolt the adapter plate from the transmission, then temporarily detach and remove all attached hoses, adapter plate, and warmer-cooler to simply get all that out of the way for installation of the cooler pipe assembly.

 

One elbow and hose is fluid coming out of trans. Other is fluid returning to trans. That's how the trans fluid gets into the warmer. Picture those hoses longer, going to an auxiliary cooler.

 

JohnLakeman said it wasn’t a thermostat. I guess I thought it would need a thermostat for the atf fluid. But no matter what it’s called, why not just add an external cooler for $50 instead of trying to tie off your coolant lines?

 

This is what the 4.6L A760 transmission thermostat looks like when the truck is equipped with the external cooler (see link):

https://parts.toyotaofcoolsprings.com/oem-parts/toyota-thermostat-unit-3297134030

@Ghost23 photo does not have the thermostat because the 4.6L illustrated does not have the external cooler. Here is another diagram of the A760 without the external cooler.

 

Ok I see. I thought those metal squares were plugs.

 

Yeah, I knew what you were thinking from the beginning. Someone accustomed to buying standard generic pipe elbows in black iron or galvanized at HD would not recognize them as a simple pipe fitting.

Those are actually called "street ells", which means they are an pipe elbow with a threaded male pipe thread on one end (threads into transmission case) with a hose barb off the hexagonal body to accept the hose connection to the warmer, or in the original application, an external cooler.

They are a specialty fitting that Toyota has made to their specifications by some international supplier. If you order enough of anything at one time, you can find a specialty manufacturer that will tool up for a special run.

 

I said I wanted to add an auxiliary cooler.

 

Yes, but without rereading all the posts I thought you also said you wanted to tie off the coolant lines, which I said I thought wouldn’t do anything. I have the warmer and ext cooler and my trans runs 185-195, engine is usually around 200. So the cooler cools more than the warmer warms.

 

Hi All,
Quick update since I see the thread grew substantially. So on my 2020 I installed the trans oil cooler, similar setup to my 2010, with all OEM parts from Sparks and the B&M cooler from Amazon. Cost me under $300 shipped for everything.

I'm under full warranty, recent Toyota dealer service didn't mention anything about it, and the engine runs way cooler and no issues towing the same route and temps which caused the overheat warning. If I knew from day1, I would have done this right away.

Happy New Year!

 

Oh well , ended up adding a cooler myself for peace of mind and because I tow a travel trailer and don’t have / want to keep thinking this