Towing problems- No transmission cooler on 2020 TRD Pro

Mike is towing the corparate line.

 

You have a cooler.

 

Bean EATERS ruin even more things ...

 

However Toyota spins it, when a sticker in the USA says "tow package" and "cooler" the vast majority of buyers assume that the vehicle has a stand alone cooler designated for the transmission. This could get expensive for Toyota if they have to add transmission coolers due to a lawsuit.

 

So there are AC lines running to the external cooler on 2018 and older Tundras with the factory cooler? In addition to the trans fluid lines coming from the transmission?

My aftermarket cooler just has lines to/from the transmission. Still keeps the pan at 200°F or lower.

 

2007-2014 have a normal air cooled separate cooler up front
2014-2018 have the transmission cooler as part of the AC condenser up front. it's not cooled by the AC, it's just a dual purpose cooler.

either way adding the OEM Toyota thermostat to the 2020s seems dirt simple, I would just look around for a dealer who is willing to install it.

 

Thanks for clarifying. I meant to say the AC condenser and tranny cooler are built as on unit but there is no heat exchange that takes place between the ambient coolers.

 

Interesting read

https://bobistheoilguy.com/forums/threads/2019-tundra-atf-burned.332138/

 

Looks like this forum is not the only one that goes sideways once lubricants are mentioned.

 

The pin is only really there for when you would change or add fluid as pinning allows the fluid to flow to the cooler before it gets up to temp. I leave mine unpinned.

 

Right, like I said, this is just to compare my temp, in specific conditions, to the '19+ without the cooler.

 

Just to further clarify, 07-mid 10 had the separate cooler. Mid 10-18 it was combined with the ac condenser. My 2010 was built in may and it was integrated in the condenser. 2010 was the year of the change.

 

If there is no heat exchange between the AC condenser and the transmission cooler, how would a change in AC refrigerant make them drop the ext trans cooler?

Edit: looks like Ruggy’s link answered my question. The new refrigerant needed a larger heat exchanger/radiator to run efficiently, so the previous radiator that was half for the transmission and half for the AC was dropped in favor of a larger AC-only radiator.

 

Very interesting, thanks for posting that. Those Blackstone results V/S the color of the fluid is intriguing.

 

Nice to see someone do a lab analysis of WS fluid from a transmission that has done towing without a dedicated air to liquid, or liquid to liquid cooling loop. Despite high temps the fluid held up fine and there was no excessive particulate in the fluid.

Maybe, just maybe Toyota and AISIN know what they are doing. I wonder if a lot of the angst in here is based on what ATF fluids used to be capable of withstanding vs modern fluids. Look at how amazing modern engine oils are versus what was common 40 years ago.

 

This! I agree 100%. I never tow anything of any weight over 62, 63. T/H mode, s4. . Not even because of the lack of cooler. I've been that guy who has had bearings come apart at 70, 75 mph. . .and a couple blowouts on trailers. . Thats why and if it helps my truck last longer, all the better. I just dont get in a huge hurry when towing. I realize I don't tow for work so for those that do and want a cooler, add one. I think some of us will be ok without it.

 

That is what I needed to know. Thanks.

sometimes it is discussed as an alternate way of running during normal operation.

 

Some people do leave it pinned during normal driving. I tried it out once. It just makes the fluid always flow to the cooler. But that’s against Toyotas design of the atf thermostat and makes it harder for atf to get to normal temps. Mine stayed around 170 pinned and stays at 190s unpinned during normal driving not towing anything.

 

But why would you ever leave the pin in and prevent the thermostat from doing it's job?

 

Yes, the fluid may be able to handle 260°-300°F, and apparently Toyota says it can, as they removed the cooler and raised the warning temp.

What remains to be seen, however, is how the transmission’s internal parts (e.g., the rubber seals) handle repeated/sustained temps of those kinds over time, particularly at mileages/time frames after the warranty expired. We haven’t got there yet. And I know I didn’t buy my truck just to safely get through the warranty or to 100k miles. I bought it based on its reputation and history of easily reaching 300k miles and beyond.

I don’t doubt that most 19-21 trucks will make it through the warranty period without issue. But in a few years, when the warranty is expired, I can’t help but think that problems from this cooler-less system going to start showing themselves. Gears slipping, the dreaded rumble strip feeling, etc… If you repeatedly tow even smaller loads (<5k lbs) or drive through the mountains, and your transmission temp is consistently north of 230° or 250° with no thermostatically controlled cooling system to keep temps in check, how is that not going to haunt you later on down the road?

Everyone says, “trust the engineers!” Well, I generally do. I bought the truck because it’s generally overbuilt for its capabilities. But when they delete an entire system (that they designed!!!) because of a change in a completely unrelated system (the AC), that doesn’t seem to follow Toyota’s history of careful, over-engineered designs meant to give extremely long service life to overbuilt parts well past the warranty period.

And then the kicker, for me anyway: the anonymous Tundra engineer who criticized the decision for all the same reasons and who said Toyota has seen failures due to high temps. “Oh you tRuSt aN AnOnYmOuS iNtErNeT eNgInEeR?” Yes. I don’t believe COTJ is lying, and I do trust someone speaking candidly off the record more than another engineer speaking as a public relations apologist on behalf of Toyota.

Others disagree. That’s fine. I added the cooler. $750 and a couple hours of my time to have it perform the way it was originally intended, the way that earned the Tundra its track record and reputation for reliability well past the warranty, was very much worth it to me.

 

Well said!

 

I wouldn’t and I don’t. I just tried it out once in the summer to see what happened.

 

Maybe I missed it but did someone from Toyota say that's why they deleted it?

 

Aren't you driving a Toyota as well even with their rusty frame and leaky tower history?

 

Had not heard before that they raised the warning temp. Is this true?

 

Would be interested to know how many of the 4.6 tundras without the tow package made it over say 200k miles? Wouldn’t this setup be somewhat similar to that? You don’t hear anything about those tundras having failing transmissions.

Everyone knows good and well some average joe that has no idea that 4.6 is missing a trans cooler has put his own hitch on there and been towing stuff around with no problems. Until we have significant documented cases of this trans failing without the cooler the debate is really just personal preference.

 

Aren't the two million mile Tundras 4.6s? I know at least one was used for hot shot, so heavy hauling if not towing.

 

I trust the numerous Blackstone reports that normal.

 

I would like to know this as well the failure rate of transmissions behind the 4.6l pulling heavy loads. In all fairness though the 4.6l HP and torque numbers are not at the same level as the 5.7l so the transmission is under less stress.

 

All those reports show is that the fluid can handle 260°-300°F. But that does not mean the internal parts and seals of the transmission can handle repeated/sustained temps at that level, especially for the 300-500k miles people routinely got out of their Tundras that came with the factory ext coolers.