wow this looks great. Wonder if it will kill the warranty though.
Transmission Overheating - anyone else?
- Thread starter fuzznuts
- Start date
wow this looks great. Wonder if it will kill the warranty though.
That is exactly what My Jeep Rubicon 4xe had with the towing package from the factory and never had issues with temps, highest temp I ever saw was 215 on some heavy duty rock crawling stuff. I wish Toyota did the same.
IMO, if there were a puncture to the Ext cooler or a cooler line that ruptured, causing a Xmsn failure, then one might have a warranty issue. Other than that, the Dealer/manufacturer would have to prove the Xmsn failure was caused as a direct result of the cooler.
Looks like the perfect solution, since they don’t ship to the US currently and it’s already $600.00, I’ve asked them which core they are using from Tru Cool.
I think I know but will wait to confirm, the price as available in the US is about $175.00 with a set of universal brackets in the kit I’m looking at currently.
If that’s the one I’ll pull the trigger and see if it can be installed with the universal kit or needs some bracket fab?
That've be awesome. Keep us updated please.
Kaon, got back to me the core is a Tru Cool LDP4454, I’ve ordered a universal kit from and transmission distributor stateside for $160.00 will update once I get home and get a chance to install.
Kaon, is also looking for a way to import that isn’t so difficult so they are trying to support US customers as well and will remove the banner on their website when they have the solution.
Kaon, is also looking for a way to import that isn’t so difficult so they are trying to support US customers as well and will remove the banner on their website when they have the solution.
Following!!! Thank you SO much for sharing
WookieBait
Active member
Will those do much for you at low speed with no fans?
Looking at the PDF, I posted it on here somewhere, the US variant LC has a Liquid (antifreeze) type cooler. Now the one in the video may have the exact same type cooler (IDK) and IMO, adding a Xmsn cooler has only one drawback...... possible warranty issues should a failure occur due to the installation errors or a failure of the cooler components leading to the loss of lubricant and Xmsn failure..
Legend! Let us know if it works out!
I’d have to look but the other cooler external to the radiator is likely an oil cooler/heater. My Volvo has two identical units for the Turbo which continues to ran the rad fans and circulate the oil after ICE shutdown when needed for Turbo cooling.
The OEM trans cooler is internal to the radiator (liquid to liquid to air) a radiator within a radiator and is both a cooler and a heater to aid in quickly reaching operating temp. Very important to keep the radiator fluid clean and neutral PH as if that corrodes the internal radiator then you’ll get contamination of the trans fluid which would likely result in rapid failure.
The aftermarket (liquid to air) will have the benefit of radiator fans to aid in cooling at low speed and the additional 30% cooling capacity will help even without the fans on. The design also allows for rapid heating to get to operating temperature.
Seems to be a great product used widely across fleet vehicles from multiple transmission specialists.
Important to note it will require slightly more fluid but the Toyota fill procedure would account for that so nothing different on the drain and fill procedure if properly filled when installed as show in the video other than the additional fluid.required during the Toyota drain and fill.
I would say one of these and the OTT tune that adjusts shift behavior among other things will do wonders for the temps.
Also I agree with @EOD Guy on the warranty issue and would caution one step further that you should completely remove if you chose to install and then at some point have trans issues under warranty. Doubt they would see it during regular maintenance but would likely find it during a trans issue troubleshooting event.
The OEM trans cooler is internal to the radiator (liquid to liquid to air) a radiator within a radiator and is both a cooler and a heater to aid in quickly reaching operating temp. Very important to keep the radiator fluid clean and neutral PH as if that corrodes the internal radiator then you’ll get contamination of the trans fluid which would likely result in rapid failure.
The aftermarket (liquid to air) will have the benefit of radiator fans to aid in cooling at low speed and the additional 30% cooling capacity will help even without the fans on. The design also allows for rapid heating to get to operating temperature.
Seems to be a great product used widely across fleet vehicles from multiple transmission specialists.
Important to note it will require slightly more fluid but the Toyota fill procedure would account for that so nothing different on the drain and fill procedure if properly filled when installed as show in the video other than the additional fluid.required during the Toyota drain and fill.
I would say one of these and the OTT tune that adjusts shift behavior among other things will do wonders for the temps.
Also I agree with @EOD Guy on the warranty issue and would caution one step further that you should completely remove if you chose to install and then at some point have trans issues under warranty. Doubt they would see it during regular maintenance but would likely find it during a trans issue troubleshooting event.
I kept track of all my temps over the last trip from sea level up to ~5,000 feet or so. Never had any temp spikes.
Yes , the petrol variants has an additional oil cooler and also not sure it'll fit the same way as the diesel variant shown in the video as the petrol one has shutters on front of the radiator.
I’ve put mine to the test with 8,000 or miles towing a #4,500 trailer over the past year. I keep it at around 70mph on interstate and drive very pretty conservative. It gets to the right edge of the “gear” symbol even when climbing and elevation. I flushed tranny at Toyota at 10,000 and tech said everything looked tip top on fluid but I will likely do every 25k since I tow with it. Toyota guy thought I was crazy and it was expensive but worth it to me.
Also, just observed last weekend when in the mountains off-roading and in steady slower climbs (under 15mph) in 4H tranny temp also climbed to right edge of gear symbol. I dropped to 4L and it quickly went back down to normal temp. I’ve read in other forums that the tacoma also has similar tendencies due to differential speed and torque converter overheating in 4H so 4L could be more appropriate depending on steady climb, or gravel road, for some off-road scenarios where typically I would have stayed in 4H.
Also, just observed last weekend when in the mountains off-roading and in steady slower climbs (under 15mph) in 4H tranny temp also climbed to right edge of gear symbol. I dropped to 4L and it quickly went back down to normal temp. I’ve read in other forums that the tacoma also has similar tendencies due to differential speed and torque converter overheating in 4H so 4L could be more appropriate depending on steady climb, or gravel road, for some off-road scenarios where typically I would have stayed in 4H.
Went to Mount Washington this past weekend. Manual mode kept temps right in the middle of gauge.
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WookieBait
Active member
OTT looks to be looking into this on the 4runner, hopefully a fix if not from Toyota a tune might be in our future.
www.4runner6g.com
Taking a Deeper Look at Transmission Overheating in 4Hi
Hey everyone, We’ve been following the discussions around transmission overheating—particularly when operating in 4Hi—as highlighted in these threads and others: 2024 Tacoma Transmission Overheating on Long Climbs Off-Road Transmission Overheating in 4Hi When Going Uphill – Toyota’s Answer (or...
www.4runner6g.com
I received my Tru-Cool core universal kit and did a quick test fit. It will require some slight trimming of the plastic below the grill shutters between shutters and intercooler to fit in front of the intercooler with the proper 1” gap called for in the instructions.
The additional cooler pictured earlier is for both the transmission and hybrid unit under the hood.
1 line from trans runs into the small cooler in the corner that you can see external to the rad and then into the rad after that and back out of the rad to the other transmission line going back to the trans.
Waiting for proper high pressure hose clamps and some ATF WS to install it.
Need to find out which is supply and return as well and then I’ll do a write-up on the install.
The additional cooler pictured earlier is for both the transmission and hybrid unit under the hood.
1 line from trans runs into the small cooler in the corner that you can see external to the rad and then into the rad after that and back out of the rad to the other transmission line going back to the trans.
Waiting for proper high pressure hose clamps and some ATF WS to install it.
Need to find out which is supply and return as well and then I’ll do a write-up on the install.
This guy's Tacoma transmission #2 sounds similar to the issue I see with mine in the LC - 230F to overheating in 4Hi. For me it doesn't matter whether you're in manual shift mode or not. Even in 4Lo, can't keep transmission temps lower than 230F on Imogene Pass. A number of these transmissions have overheating problems. I don't think I'll be keeping mine beyond the 6 year/ 60k powertrain warranty. I wonder whether Toyota will have it fixed in the '26-'28 YM when I'd plan to trade mine in.
WookieBait
Active member
On a dirt trail today, not off roading, a road that a Prius could drive easily, going around ~10-15mph on a very slight incline not even something your even think about normally watched my transmission temps on the digital gauge go right to red within a few minutes of driving. This was in manual mode in 1st gear. No idea the actual fluid temps just the dummy bar. Temperatures here around the high 70s..
I don't know how a transmission cooler would help when it's overheating almost instantly. This seems like I have a bad transmission. Or this is a major design flaw. Leaning towards design flaw seeing many others have reported same problem in Tacoma, 4runner and lc250...
Contemplating just selling this thing and getting a lc200.
I don't know how a transmission cooler would help when it's overheating almost instantly. This seems like I have a bad transmission. Or this is a major design flaw. Leaning towards design flaw seeing many others have reported same problem in Tacoma, 4runner and lc250...
Contemplating just selling this thing and getting a lc200.
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