2024 Transmission getting HOT in 4x4 climbing hills, skidplates?

OH FOR SURE! You can't do that in any vehicle...

 

Thanks - that is what I needed to see. I did look at it and the process is exactly what I did on my Tacoma - external oil/air cooler in series and it worked wonders. I did not install fans - just used air flow from traveling speed to provide cooling. Kept my tow and normal use temps sub 195 at all times. I will be adding this to my Gen3 Tundra. Very simple to do. Just have to take your time and not hurry.

 

Yea, I think the concept is a pretty good idea, but I didn't really like his execution of it, so I didn't post it. I didn't like some of the janky mounting and how he had metal on metal contacts in certain areas. Electrical tape and foam, no thanks. I would have spent some time to make some better brackets and use washers too, along with making something to better route the hoses. There's a better way, but the idea of the series cooler add is decent.

 

I think long term Gen 2 owners possess really good "dry" senses of humor. lol

You must own a Gen 2? lol
maybe the Volvo station wagon my wife had at the time is responsible for our fraternal twins.

I could not include your whole quote because it is too long but it had really good info. Very interesting comments from an experienced tow-er and 3rd Gen owner. There is no question from reports that it tows well on highway and at speed. But slow it down, with heavy load, on a long hill and .... well interesting.

@SDHNTR
the dealership never called me back on max speed with 4 Lo. They don't know, its not common knowledge, and its not in the manual apparently. So Toyota assumes anyone that gets the blinking lights should slow down I guess. If I get an answer I will post it.
So try 4 Low next time and let us know if it still over heats and maybe more important, if you can live with driving like that.

 

Cant do what? Drive up a long hill on a paved road in traffic in 2wd without overheating the transmission?

 

I haven't done that.

 

That's the plan. I'll be back at the ranch in a couple weeks and will report back with my findings. Going to experiment with 4L and tow/haul. Gonna take my skidplates off too.

 

Welp, 20mph felt like warp speed. 25mph felt like Ludicrous speed. Though I got her up to 30 I never got to the nirvana of Plaid. Then I remembered I have a transmission cooler.

 

I agree on the workmanship stuff. Only one way IMO to do things and that is the right way the first time. I will do more first hand review before gathering parts. Proper brackets and connections are a must. No way you want any contact between parts/ piping/hosing or metal frame.

 

I wouldn’t take off the skid plates, it will skew your results. You want to replicate the conditions as close as you can while only changing one variable at a time.

 

I was thinking about this based on the conversation yesterday. The dealer won't be able to give a max speed for 4 Low because all our conditions vary on our use, and they have no idea how we are using the vehicle. 1) Hauling or towing or both 2) Terrain. 3) Speeds being used. Other factors.

So I guess you use 4 Low until you get the blinking light. (if you can put up with it) 8^0
If enough people complain to Toyota about this type of towing and terrain (long hill/slow speed) maybe they can do a software change, if possible, to the transmission.
As a future update.

 

Pretty sure someone in the 3rd gen forum has already done a write up for a thermostat-controlled aux transmission cooler.

 

so you got a tail on that?

 

We take our rig that's overlanded out up into the mountains going from 4300 to 9700 ft elevation consistently, loaded out with 600 lbs of weight, and been doing that pretty often. We also recently purchased a Taxa Mantis loaded out is around 3k in weight have do the same drive on tow mode. Haven't seen any overheating issues but you got me worried now. We push our rig hard, already have 46k miles after a year and half of ownership.

 

too late. Already took em off. And at this point I dont care what solves the issue as long at it gets solved. Even in just looking at the Talon's garage skidplates, they cant help but hold in heat. They really enclose the trans and T Case thoroughly, with 1/4" thick aluminum. Even if they aren't actually causing the problem, they can't help either. If I do put them back on at all, I will be getting out the hammer drill and going to town on them with a 1/2" drill bit.

 

Anything 20 MPH and under is 4Lo territory. I've been at 20 MPH in both my Tundra and Tacoma in 4Lo with 6 speeds. They are fine with it.

That's what happens in a high load scenario. If you want low RPMs when making it work, get a diesel. Gassers use revs.

What you like/dislike doesn't really play into whether or not the solution is the proper way mechanically. If you are averse to RPMs then you need to not ask a lot of your vehicles. That's the nature of the beast. Work = revs.

 

BS! Anything under 20 is not necessarily 4Lo territory. Not if it's not steep. I'm not new to this. I've done this same drive with 7-8 other vehicles, only one diesel and the rest gas, and NONE of them struggled this way. Most of those lasted well over 200K with hard 4x4 use. This truck is unique. It may be mechanically operating the way it was designed, but not the way I need! And not the way other vehicles operate on the same terrain and under the same usage conditions.

 

Did the other vehicles have external transmission coolers? What years and make/model?

 

To clarify, I meant anything that needs 4x4 and is under 20 MPH is 4Lo. Purely because it will keep the transmission temps lower.

 

Nothing aftermarket. Everyone was completely stock. Some had the same radiator heat exchanger design too. 2015 Jeep Rubicon. 2017 4runner. 2019 F150. 2023 Ram. None ever even came close to needing 4Lo for this same drive. None showed any sort of overheating of any kind. Not even warmer than normal at all. Just to name a few of the more recent vehicles, there have been plenty older too. This wouldn't be hard for Toyota to address, just kick the fan on sooner.

 

I disagree.

 

Then you’ll keep cooking your ATF.

It’s not really debatable - monitor temps each way and there is a HUGE difference.

 

How is it not 4Lo territory? I've been told by almost every single dealership regarding EVERY 4WD truck I've owned that you don't want to go over 15 or so with 4Lo, regardless of terrain.

As Godzilla mentioned...did the others have external tranny coolers? I've owned many trucks, and only ONE didn't have a full size aux transmission cooler. I'll let you guess which truck that is. It rhymes with "2020 Schmoyota Shmundra"

Does it suck? Sure. Can one purchase a supplemental transmission cooler to assist with the issue - OR put it into 4Low to rectify the transmission temps issue? Also yes.

I don't disagree that it's silly that they don't make an aux transmission cooler available...but I mean, 6 pages of discussion for an issue that HAS workarounds or solutions. If you don't agree with those workarounds...sell the truck, I suppose.

 

Ha. If that were true I would have blown up multiple transmissions already. And that's not true. Only had one tranny give up in my life and that was after 120K hard miles on a 99 F250 that was known to be a weak transmission to begin with.

 

[/QUOTE]
Nowhere did I say that you should be able go over 15ish mph in 4LO. Quite the opposite. I said if the terrain is not steep or difficult, you shouldn't need 4Lo at all. You should be fine in 4H, regardless of speed. It's not 4Lo territory because it's not steep! It's not deep snow or mud. The truck shouldn't be working hard. This is child's play.

 

You just improved your deep snow off road capability by removing the skidplates. 8^)
just don't hit any rocks.

I just did an oil change on my truck and I was so tempted to leave the skid plate off because of the hassle to remove and re-install. But I put it back on.

My beloved 2018 Tundra - and you know something, with every year that passes, this freaking Transmission Cooler on my truck seems to become a more valuable "thing" than the year before.
(According to this forum)

 

If it's not steep or difficult, why are you in 4WD in the first place?

 

I read what you said. I'm just reporting what the dealerships have told me.

I get and mostly agree with the fact that the truck shouldn't be working hard enough to require using 4Lo to mitigate the temps; I get that it's not deep snow or mud, etc.

Doesn't change the fact that your temps are rising AND that putting it in 4Lo resolves the temp issues....just not in the way you want.

Aside from what we'd ALL like to have (the ability to drive along slowly without engaging 4Lo to mitigate high temperatures - and maybe an ACTUAL aux transmission cooler) what is it you want, or want others to say? I feel like neither side is going to budge here.

 

Almost like turning two driveshafts is twice as hard as turning one… use the extra torque.

Comparing your F250 (an HD truck) to what’s happening in your tundra is 1000% irrelevant.

 

I have to side with the OP on this one. This sounds like a major engineering flaw with our trucks. Many of us travel at slow speeds on roads that don't necessitate 4LO from a traction, obstacle, or steepness perspective. Now, we're forced to use 4LO to prevent the trans from burning up? That's utter nonsense, and very disappointing to me.