Transmission cooler or not Thread

It is actually tied to engine temp. Mine will not shift till the engine temp hits 139 degrees. In the winter this can take a while Watch the engine coolant temp on your Scan Gauge sometime.
This is common for many Toyota vehicles. My 80 series would not shift out of 3rd till somewhere around this same temp. They do this to get temperatures up AND to not rely on thick oil to make to the bearings while lugging the engine. Some additional revs keeps the thick oil flowing.

 

I'll watch the coolant temp next time I'm out and see where it is when I get into 6th.

 

I dont disagree that keeping the fluid cooler is a good thing but I have a different experience and mind you I have a 20 row setrab cooler. Pinned open I did not see temps much different. The problem with pinning it open is that it takes the fluid longer to warm up, especially in the winter and having it too cold is a thing, blow 60° the torque converter will not lock up so getting it up to temp faster with it unpinned does serve a purpose.

 

agreed on the Cold thing.

In Houston, we don't even know what cold means.

 

Try driving one of these when the trans temp is 0 degrees. They don't love life very much. Can't wait of the trans temp to come up

 

we rarely crack freezing down here!

 

I noticed the same thing w/my '21 (won't shift to 6th until warm), but the '08 doesn't care...

 

Anyone on here with a cat shield notice much change in transmission temps before and after?

 

I think I recall a comment on that in the RCI / Catguard threads...

It was brought up a few times, but the responses were that it did not have a negative affect on temps. I have not checked this on my own rigs though....

 

I would be surprised if it did. The little bit of cooling that is provided by the airflow over the pan vs. the liquid to liquid cooler/heater that these all have is negligible. Not to mention the guys who have the additional air/liquid cooler in front.

 

Ended up installing one recently on my 19. Used to see over 230 when towing. Wow, this thing never goes above 200 when towing now. Makes me feel good when I see these low temps. Did a drain and refill also.

 

What gear are you towing in?
What are you towing?

Trying to see if your results are consistent with others.

 

I have a GCS kit and keep it pinned. These trucks don't take long to get up to temp, even if you baby the throttle. With the thermostat pinned, I see temps of 175ish while cruising on the freeway and the truck is perfectly fine.

 

No. The max pan temp I typically see is 203F. Same prior to cat shield.

I should add I installed a transmission cooler and I have a Millercat shield. It has some venting in it, but it covers that area completely between the frame rails and crossmembers.

 

This is my 1st Tundra and first truck that never had a trans cooler. I was definitely skeptical after I found out, but after owning and towing my boat all the time and reading from this forum, I always do Tow/Haul and S5. If I know it’s flat ground, than I will bump it into 6th but SHIFTS create HEAT. So I just usually leave it in S5 and let it eat

 

5000lb camper or 6500lb bobcat rig. Letting tow haul do its thing. Saw several hills on last two camping trips.

 

Thank you for sharing.
This is consistent with what I have seen. Let the truck run on OD (5th or 6th) and the trans will heat up. You will likely need a cooler to keep things below 240ish. Lock the truck in S4 and the trans pan temps stay sub 220.

 

Just FYI tow haul only changes the shift points to give you more power starting off from stop and will hold a gear longer before shifting, doesnt really do anything as far as heat goes, it doesn't lock out 5th or 6th which is where you will see the most heat build up

 

blackstone report back today. I guess looks aren’t everything…

 

Good for you and your transmission, very nice. Cracks me up how they try to make the response seem so natural.

I am putting on a cooler soon.

Wondering if I should drain and fill first? I heard Toyota factory oil is crazy expensive...what is your experience with that?

I kinda want to see what is on the drain plug because I was in a rear ending that totaled my tundra and I bought it back. Just did rear diff and got a single small shaving from a gear. Curious as to what is on the Trans Plug or in the oil that will come out. I only have 22K on her('21).

 

The Toyota ATF WS fluid was about $15 a quart. Not too bad. I installed the cooler as a precaution since we tow a good bit.

 

Good report! Thanks. Have you checked your thermal degradation number yet?

I'm curious if it is only thermally related or has other factors (such as time). My '20 was at 60k miles and just had the cooler installed when i checked it. It was at 3699 at that time. I'm 7k miles later now, pan temp has not been over 200F again, i need to check the number again to see if its changed.

 

Do tell!
What is this number and how do you check it?

 

You can read the thermal degradation number with an OBD reader, the OBDlink MX+ comes with the ability to read it out of the box, not sure about other adapters.

 

I agree - now the trick is getting it to stay at 200 or so under sever strain that cannot be helped in any way. What strain - Stop and Go repeated - its cannot be helped - even accelerating at Slow speeds staying behind everyone mine still got to 248 - do you think that is acceptable long term?

I did not and did something about it with a cooler (one which opens up at 185) and a fan - now under the same severe situation it only hits 204 = ahhhh. It cannot be done without the factory cooling or similar. Can it live indefinitely hitting 248 - maybe yet I don't want to find out the hard way - Luck all deciding what to do.

 

I assume that you are towing in this situation?
Mine says very cool at lower speeds even doing stop and go. I think that this is because I am not using a whole lot of horsepower. The transmission temperature is directly related to how much horsepower you are pushing through it.

 

No - that is normal driving - no jackrabbit starts or stops - I even stay behind other traffic in attempting to not accelerate too fast (I watch the temps via torquepro for accuracy of both pan and tc temps). I am in central texas heat yet its 'only' 100 or so this summer.
248
The OEM dash gage is an interesting setup - it reaches the middle at 125-130 (trans temps) and stays there without moving at least until 248. Not terribly useful to me.

That is why I decided to do something about it and do what Toyota should have done when they labeled this vehicle as having a "tow" package. I think all they include are stiffer rear springs - a hitch and the supposed trans cooler that is really mostly a heater to get it to operating temps faster. maybe it would be fine with that setup yet I can't stand 248 showing constantly. Luck all.

 

That is interesting that you see temps that high. I wonder if it is because the Sequoia is geared differently than the Tundras? If I recall correctly the Sequoia runs 4.10 gears or maybe even 3.73 where the Tundra is 4.30.

I have seen temps in the 220s in similar conditions. I am not loosing sleep over trans temps. I run the WS fluid and I am old school. I drain and fill every 30,000 miles.

 

I've seen those temps only very briefly on my Scangauge but it's neen TF2, which is considered to be fluid very near the torque converter. And that's pulling a trailer westbound I40 going up Black Mountain just east of Ashville.

 

how long should it reasonably take to install the GCS kit?