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

Does Toyota make a factory upgrade cooler? I don't want to modify anything under warranty that could give them a reason to void a claim, even for something that's supposed to help.

 

So does anyone actually know what the fluid temps are rather than just reading the bar?

 

You are in Low Range territory based on the conditions. If you go too fast it will start flashing on you in Low Range.
I have asked my dealer to let me know what the max speed allowable is in Low Range.
They said they will call me back. Service guy said the manual does not cover maximum speed ?
This is no different than trying to bike up a hill on a 10 speed. You won't get very far in gear 5 and up.

 

Then I'd say there is a significant cooling issue here. S2 and still overheats (did you actually measure the temps BTW) or just use the silly dash gauge - I'd say this vehicle needs some auxiliary cooling - I use a haydon 699 - doesn't open till 185. Luck

 

For those of you running this thing in 4Lo in similar conditions, how frustrating is it to drive in low under these conditions? In my previous vehicles, 4 Lo was a 5-10mph max thing. That's not going to work for me. Can you drive a little faster in these 10 speeds in 4Lo? Can I run at 20-25 mph without annoyance and 4000 rpms?

 

Ouch

 

Sweet baby Geezus! Are you still on the same fluid? Or did you change it out? Burned? With no dipstick how do you even check?

 

Important to note whether that’s converter or pan temps.

 

I feel your frustration. I drove my 2008 and 2015 Tundras all over the Colorado back country and only needed 4LO a handful of times, and those were real 4X4 2-tracks, not maintained gravel roads. This is definitely disappointing news to me, just when I was starting to really enjoy my Gen 3.

 

If pan temps are 297, converter temps were likely much higher.

 

Before using 4LO, use tow/haul or tow/haul+ as that forces the transmission to hold lower gears and reduces the converter torque multiplication and heat build up. Running in normal mode ranges has a tendency to lug and get into the torque converter stall ranges

 

@SDHNTR: use 4LO, plz.

 

Doesn't help that Toyota warms transmission to near engine temp in the first place to reduce fluid viscosity for improved fuel efficiency. Then any additional "stress" just builds more heat from there. (Gen 2 series Tundras did this as well)

 

Experienced similar situation this year hunting. As others stated, 4L does the trick. I did play around couple of runs up same ridge. 4H with Auto shift select in 4th gear with Tow - haul. This did help quite a bit.

 

Gen 3 Tundra, being a glorified passenger car, behaves just like a passenger car when you put it to real work. You have to introduce an aftermarket ATF cooler.

 

He perhaps can walk up and down the hill a few times, with hunting gear on his back, in less time than it would take him in 4LO.

 

Totally understand, I was/am an old Volvo fanboy, which leads the automobile safety competition.

For getting there and back I get a proper vehicle, though.

 

awwwww. yaaaaaah

there's the Volvo again

 

@Terndrerrr have you ever looked at your ATF Thermal Degradation estimate?

 

That was a joke. The guy didnt even climb 2000' feet and he said it was in the 30's out. How this thing could survive towing over a real mountain pass is beyond me.

 

Isn't the obvious solution to this whole thing to treat the road like a rally track, use 4hi, and go much, much faster?

 

I have

 

Is that OBD Fusion? I have never been able to find gear status and TC lockup.

 

I think my Volvo wagon experience is more relevant to gen 3 than gen 2 experience to gen 3. It is turbocharged, handles like dream, no transmission cooler, fine interior materials, very ergonomic layout, coil springs in rear, only 1 inch less ground clearance. 5 star crash ratings. Corrosion resistance is in order of magnitude better than gen 2 has. Half of Sweden population was conceived on the rear bench folded down (in similar wagons). It also blew a valve because of excessive pressure, heat and oil consumption via turbo-complicated PCV, had the turbo prematurely replaced, wastegate control repaired, wire harness and vacuum hoses dried up and replaced, and electronic glitches fought off as well. I don't drive it far without packing up all the tools I have and dealer-grade diagnostic hardware + software.

Meanwhile, gen2 is just a truck. Loud, rusty, does not want to accelerate, handles like shit, gulps gas.

 

Yes, both in here

 

Agree about adding the Transmission Cooler. I have found no published resale options - even DM'd the Gen2.5 source and got no response about one for the Gen3. Someday in the near future I'm gonna check the passenger side of the radiator and look for the oem feeds for the transmission integrated cooler and see if an external oil/air cooler can be added in series. Did this option on my Taco and it worked wonders.

 

Wow! Turbo does work! The highest I've seen in my previously coolerless 2.5 was like 270. That old V8 just does not have all the guts to heat it up properly!

 

It's not unique to the Tundra, my wifes pc of shit jeep you have to be in 4lo to keep temps down while slow rolling in 4 wheel drive. 2 buddies who wheel their 4Runners religiously always use 4lo and manual shift them. I use 4lo and manual shift mine as well. Never see high temps that way.

 

There's a video on Youtube of a guy doing this with a cooler and fan setup. However, it's kinda janky and not thermostat controlled, so makes you wonder if there will be cold weather issues with this approach.