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I just picked up a 2010 Platinum to replace my 2007 DC Limited Off Road and noticed that the transmission cooler that sits in front of the rad on my 07 is not there on the 2010. The truck has the tow package and it lists a transmission cooler on the window sticker ???
 

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Search the forum, its been discussed before and someone has a picture showing it. Its there, its smaller and in a different place on the 2010's apparently
 

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Actually, they changed that in mid 2010, some 2010 5.7s have the separate cooler but most have the trans cooler redesigned and integrated into the ac condenser in front of the radiator, ALL 4.6s have the integrated type. I know this from looking at the TIS system diagrams for early and later Tundras.

When you open your hood you will see the cooler lines are now routed into the top area of the condenser, if you look closely at that you will see a small separation point, the trans cooling area of the unit takes up about 25% of the cooler in the top area. I contaced Toyota about this and tried to get and answer as to why they did it, but did not receive anything but the company line....I wanted to know if the new unit is as efficient or less or more, and if it had any effect on ac efficiency....no real answer was forthcoming just something about how it was tested by engineers.

On the upside, the new unit probably has better air flow. On the down side, it has to share space with the ac condenser. I think it was a cost saving move. Looking at it though, one could easly add an xtra cooler where the old one used to be located. All that said, I have towed now for around 5000 miles and been up some pretty steep grades in the heat of summer with the ac on full blast. The trans temp gauge never moved, nor did the engine temp.
 

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Actually, they changed that in mid 2010, some 2010 5.7s have the separate cooler but most have the trans cooler redesigned and integrated into the ac condenser in front of the radiator, ALL 4.6s have the integrated type. I know this from looking at the TIS system diagrams for early and later Tundras.

When you open your hood you will see the cooler lines are now routed into the top area of the condenser, if you look closely at that you will see a small separation point, the trans cooling area of the unit takes up about 25% of the cooler in the top area. I contaced Toyota about this and tried to get and answer as to why they did it, but did not receive anything but the company line....I wanted to know if the new unit is as efficient or less or more, and if it had any effect on ac efficiency....no real answer was forthcoming just something about how it was tested by engineers.

On the upside, the new unit probably has better air flow. On the down side, it has to share space with the ac condenser. I think it was a cost saving move. Looking at it though, one could easly add an xtra cooler where the old one used to be located. All that said, I have towed now for around 5000 miles and been up some pretty steep grades in the heat of summer with the ac on full blast. The trans temp gauge never moved, nor did the engine temp.
I do have an early 2010, so that would explain why mine is hanging out there in plain sight.
 

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the new incorporated design is cheaper to produce and install on the line.cooling may improve also since even more of the fan airflow goes over it.
the original design showed it's limitations during high temp low speed use hence the relocated cooler in later revisions.
 

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I will have to concur on the low temp cooling ability of the new design. The tow I described above was over an 8%+ curvy slow grade at 6000 feet. Temps were in the 90s, I was towing a 6000 pound trailer and my truck was full of gear. I was using 3rd gear mostly and running 3500 rpm. AC was on full blast. As I said, heat guages did not move, performance was perfect and all this with the 4.6. I was skeptical of the new system, but after using and abusing it, I think it works.

On a side note, compare the same tow with my 09 Silverado 5.3 (towing the same trailer on the same hill) and temp guage went up steadly, tans temp reached 230 degrees and I ended up having to turn off the AC just to help it out. In fact, this may have been the tow that half way fried the torque converter and where the rear end got so hot the paint blistered.....or was that just rust causing the paint to peal??
 

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On a side note, compare the same tow with my 09 Silverado 5.3 (towing the same trailer on the same hill) and temp guage went up steadly, tans temp reached 230 degrees and I ended up having to turn off the AC just to help it out. In fact, this may have been the tow that half way fried the torque converter and where the rear end got so hot the paint blistered.....or was that just rust causing the paint to peal??
Your experience there caught my interest. I'm assuming you had the HD cooling pkg on the Silverado, so that's the highest temp I've seen anyone mention. Based on (a forum) conversation w/ a GM engineer, 230F is right on the edge of where they start to care w/ the Dex-VI fluid (limp mode for forced cool down starts ~260F). A question that I keep having is "what kind of temp measurement does the Tundra actually have for the transmission?". Every post I've read says "the needle never moved". One post I read (somewhere) was a guy that drove his Tundra (unloaded) across town and he measured the trans. temp casing w/ an infrared gun. It showed 200F, and the ambient temp was pretty low (maybe 50F?). Does anyone know what "normal temp" means on the Tundra, and how it can remain steady regardless of load or ambient temp? Does it have a thermostat or something to that effect? Every other transmission I've seen varys temp with load (as expected), so it raises the question about what the Tundra is measuring and how?
 

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Your experience there caught my interest. I'm assuming you had the HD cooling pkg on the Silverado, so that's the highest temp I've seen anyone mention. Based on (a forum) conversation w/ a GM engineer, 230F is right on the edge of where they start to care w/ the Dex-VI fluid (limp mode for forced cool down starts ~260F). A question that I keep having is "what kind of temp measurement does the Tundra actually have for the transmission?". Every post I've read says "the needle never moved". One post I read (somewhere) was a guy that drove his Tundra (unloaded) across town and he measured the trans. temp casing w/ an infrared gun. It showed 200F, and the ambient temp was pretty low (maybe 50F?). Does anyone know what "normal temp" means on the Tundra, and how it can remain steady regardless of load or ambient temp? Does it have a thermostat or something to that effect? Every other transmission I've seen varys temp with load (as expected), so it raises the question about what the Tundra is measuring and how?
I believe there is a thermostat on the side of the Tundra tranny. The FSM mentions bypassing the thermostat when checking the fluid level.
 

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Does anyone know what "normal temp" means on the Tundra, and how it can remain steady regardless of load or ambient temp?
Since the mid-1970's Toyota has engineered it's trannys to run so cool (around 150 degrees) that you can usually drain fluid without needing to wear gloves whereas GM engineers its trannys to be at 180-200 degrees even on level ground unloaded. So it stands to reason a mildly loaded GM truck will cause the fluid temp to spike up to 230-260 whereas 180-200 is about as hot as a Toyota automatic can get under severe conditions.

Ditto in regard to coolant temps. Toyota has always used 180 thermostats and the truck has to be driven really hard uphill to get the coolant temp to climb higher than 190-195. But a GM truck has a 195 degree stat and coolant temps routinely get up to 220 on grades.

Americans are experts at...planned obsolesence.
 

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Not sure on the trans temp as an actual temp on the tundra, I am on the chevy I had because it was a digital read out as part of the DIC.

I do have a KIWI connected to the Tundra however, it does NOT give me trans temp, however it will give engine coolant temp. On my particular truck, the KIWI reads 195 when at normal temp, and at this temp the analog gauge on the dash is in the middle of its range. I have never seen the temp rise beyond 203 degrees on the digital read out (at that point the fan clutch is kicking in), I mean never - not in 105 degree traffic stoped on the freeway with the ac on, towing up steep grades or running the truck hard up a slow windy grade in hot weather. When the digital readout is at about 203 I can't tell any difference in the gauge on the dash as compared to 195. One of the reasons it is hard to tell though is the fact that if I spend too much time trying to see that particular gauge down in that tube I may wreck. This is the main reason I now keep the KIWI set to give me coolant temp (since I have done the DIC mod and don't need it for gas mileage read outs anymore). Overall, after having both and towing the exact same trailer, I can assure everyone, the Chevy does run hotter under load. I will be testing this further soon as we are heading through the Canadian Rockies for a 3 week rv vacation.

My theory on why the Tundra's transmission temp remains steady during load conditions is because there are two trans coolers when you have the tow package, an oil to water and an oil to air system. The oil to air cooler is also on the large side, is unobstructed and in line with the engine driven fan system (as opposed to the electric fans on the chev which may or may not be better, I am not sure on that, but common sense points at 300+ hp turning a rather large fan as the more effective though less efficient way to go). In addition, the 4.6 Tundra six speed trans holds 3 GALLONS of trans fluid. For that matter the differential holds 4.9 quarts.

Personally I have owned a 77 Toyota truck, a 94 Toyota 4WD Truck, an 02 Tacoma 4WD and an 06 Tacoma 4WD, I towed and hauled with all of them and never once have I had a problem with engine or trans cooling, in fact I can't remember a single time with any of these trucks where the temp moved much off normal. I have developed quite a bit of personal confidence in the cooling systems developed by Toyota for their trucks.
 

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Thanks for the feedback. I guess my questioning had more to do with the lower range than the upper, and the system holding "steady" regardless. Towing a 7k lb camper w/ the GM, the transmission coolant temp is pretty much always right at ambient + 100F (within reason). So, if it's 50F outside, the transmission may be running 150 to 170. If it's 90, I expect to see 190 to 200 (normal terrain), etc. Engine coolant holds steady, as it has a thermostat to bring up the low end, but not the transmission. The Tundra showing the same trans temp regardless indicates a thermostat or some type of heat exchange to bring the temp up to some "normal operating level". Either that, or the gauge shows "normal" for any temp below some threshold value... or they're measuring the temp at the radiator itself (which is influenced by water temps). Interesting to learn about it.
 

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Yes I would find that interesting also I would like to know where the temps are measured. I can say that the oil to water trans cooler on the tundra does have a thermostat for sure, I think its main function is to help the transmission temp warm up faster for more efficient operation, it may also function to stabilize the trans temp somewhat also. I am not sure at all what the parameters are associated with the analog gauge on the tundra, I would find it interesting to know also, personally I will not be happy if I find out the gauge is actually set to read normal for a wide range of temperatures below some threshold value. Wish my KIWI would show actual trans temp.
 
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