2016 transmission temps

[kthaxton]

Is the engine temp measured at the top where the thermostat is?

It is in the head, back a ways from the t-stat.

Yes, as I was posting this I was wondering about these same things and wondering if a few degrees would make that much difference on seals and clutches. I don't expect a few degrees would make a significant difference as long as the lubricant is not burned or degraded and doing it's job.

But we are talking 30º above what others see.....that is reasonably concerning especially when other's trucks do not run in this range. It logically makes one wonder what would happen when it is loaded.

Certainly nobody is saying there is imminent danger of trans failure, but 200º is above ideal and if it runs that way all the time, that means shorter life.

 

[kthaxton]

You're surly correct. I am an ignorant sob. I'm so ignorant that I can't imagine someone who's concerned over 10f temp difference that they don't even positively know exists.

You can jump to that conclusion if you like....but again, you couldn't see how it was possible to be cooler than the engine temp. Further, both you and News's math is off. The op stated 201-203º, myself and others stated that we normally see 170-ish. That's roughly 30º.....you should stop now.

I'm ignorant alright.*

Now that just sounds like pouting, I didn't say ignorant....but if that's what you feel like after what I pointed about your statement, more power to you.

 

[DonFitzwater]

Cmon girls, hug and play nice.*:-laf

 

[kthaxton]

Gotta agree here with this. A 10-20° difference in operating temps is nothing like the 100° diffetence between a cool transmission and a transmission at operating temp. Seals clutches won't even notice that. And on cooler days, 150+ degree differences between a cool transmission and operating temp transmission. Seals and clutches are designed to work at a wide range of temps. Thermal expansion/contraction of most materials is linearly proportional to temperature change as long as no phase change occurs.

This has nothing to do with the discussion.

 

[transe]

ATF+4 is rated to handle 315 degrees for 1500 hrs before expected degradation happens, ...

What that statement implies, unfortunately, is completely false. Your transmission would probably last less than 20 hours (total) at 315°F.

.... don't think 201-205 is going to hurt it any time soon.

Now THAT statement I agree with. Running at 201-205°F will not instantly kill your transmission, but it WILL result in much shorter life than at 170-180°F.

 

[transe]

Also, (News Flash!) the transmission oil cooler in these trucks isn't in the radiator. It is an air-to-oil cooler. So all the discussion about coolant temp is mostly irrelevant to trans temp.

 

[jhenderson]

We know there's an air cooler. *We also know colder isn't better, hence the engine mounted heat exchanger. The *fluid has an optimum temp. You imply it's 170-180. How about a little insight as to the situation with this truck. Can the displayed temps be trusted? Do the new trucks have a different cooling strategy? What's the opening temp for the bypass *on a 16 ? If the thermal bypass is operating, what next? *By the way, Kthax, you didnt understand my question about rad temp. You made it sound like a dramatic difference in temp in to out and my point was to show what it actually was. Not so dramatic. And it's designed to raise the trans temp to engine temp before cooling.*

 

[transe]

We know there's an air cooler. *We also know colder isn't better, hence the engine mounted heat exchanger. The *fluid has an optimum temp. You imply it's 170-180. How about a little insight as to the situation with this truck. Can the displayed temps be trusted? Do the new trucks have a different cooling strategy? What's the opening temp for the bypass *on a 16 ? If the thermal bypass is operating, what next? *By the way, Kthax, you didnt understand my question about rad temp. You made it sound like a dramatic difference in temp in to out and my point was to show what it actually was. Not so dramatic. And it's designed to raise the trans temp to engine temp before cooling.*

Whether "colder is (or isn't) better" depends on what you are concerned about. If you're talking efficiency (fuel economy), then yes, colder isn't better. But if you're talking durability, colder definitely IS better (as long as you're talking about the normal operating range, and not 0°F or something).
Yes, the displayed temp can generally be trusted, as long as it isn't blatantly wrong (like 700°F or something).
I could be wrong (I don't handle cooling systems), but I don't think newer trucks have the engine-mounted water-to-oil cooler. Only an air-to-oil cooler.
The TBV should be fully open at about 170°F.

 

[kthaxton]

Also, (News Flash!) the transmission oil cooler in these trucks isn't in the radiator. It is an air-to-oil cooler. So all the discussion about coolant temp is mostly irrelevant to trans temp.

My 2015 has a cooler inside the radiator followed by the air to oil cooler.

Edit: dang photo rotating board software!

 

[transe]

My 2015 has a cooler inside the radiator followed by the air to oil cooler.

Sorry, I stand corrected!!

 

[kthaxton]

And it's designed to raise the trans temp to engine temp before cooling.*

These coolers do both, they are indeed coolers, that also have the advantage of bringing up the trans temps when it is very cold, but make no mistake, they are indeed coolers. In many light duty applications, and in some heavy duty applications (at least in older setups.....my old 77 motorhome for example) the radiator cooler was the only one supplied from the factory. They are very efficient for their size because they are being cooled by liquid, not air.....with liquid being a better conductor of heat, they do quite well. But obviously, not the best by themselves when worked hard. That's why it is best to have both.....the best of both worlds.

 

[Jared Herzog]

Hauled a load of metal roofing yesterday. Weight was about 12,000 and the truck had another 1000+ pounds in the bed and another 500+ in the cab. Temp was 80-88. Hauled through the hill country of Texas. Trans temp after three hours was 163 with the Aisin. Coolant ranged from 190-208. 200+ unloaded is just not right. Over 200 may not damage it right away but we are talking 30-40 degrees hotter than others report. If coolant were 30-40 over what others report i would worry. I never have heard any additional fans kick on in my truck. Sorry, but if it was my truck i would take TransEngineers advice and check that block thermostat thing.
Is atf+4 that is in the 68fre from the factory synthetic? When i have bought it for past trucks it was not but it could be now i guess.
Good luck. I hope you get your possible issue resolved before it ruins a camping trip and such.

 

[kthaxton]

Is atf+4 that is in the 68fre from the factory synthetic? When i have bought it for past trucks it was not but it could be now i guess.
Good luck. I hope you get your possible issue resolved before it ruins a camping trip and such.

What I was always told (but have never verified) is that ATF+4 is a synthetic blend. In any case, it was always mentioned as being a high quality fluid.

 

[cerberusiam]

What that statement implies, unfortunately, is completely false. Your transmission would probably last less than 20 hours (total) at 315°F.

That was only concerned with the fluid and the mistaken opinion is was going to to degrade and kill the transmission. It is assumed that the trans components are not going to like extended high temps in the 300 degree range but there are no proven absolutes. At 200 degrees give or take 10 degrees even the 48RE has been proven to live long and prosper. One should be able to draw the inference that the newer units are not going to suffer either.

At this point you have not commented one way or another on the range of observed temps. Some are saying 170 is the absolute and anything else is too high, a supposedly factory trained tech has stated the 201-203 is normal and as designed. It has been noted extended temps up to 230 when towing is an indication of problems. With all that, factory has stated that 160-240 is designed 100% duty cycle operating range for the transmissions and fluid. Is there any solid info on any of it or only interpretations?

Based on what I have seen, and the range reported here, either the sensors are NOT consistent across trucks, or, the platform configurations contribute a lot more than is known, or, there are a lot of misinterpreted readings. So far, no help narrowing down what is correct.

These coolers do both, they are indeed coolers.

Correct term is heat exchanger when used in a fluid to fluid configuration. The question is whether all trucks are configured with the aux air to fluid cooler or that is only an AISIN HD component. That will skew the number considerably.

What I was always told (but have never verified) is that ATF+4 is a synthetic blend. In any case, it was always mentioned as being a high quality fluid.

Group 3 synthetic, a blend of of base oils and synthetic additives.

 

[transe]

201-203°F is NOT normal for a 68RFE running unloaded, on level ground, at highway speeds. Something is wrong. Maybe not dangerously / blatantly wrong, but nevertheless abnormal.

 

[kthaxton]

Correct term is heat exchanger when used in a fluid to fluid configuration. The question is whether all trucks are configured with the aux air to fluid cooler or that is only an AISIN HD component. That will skew the number considerably.

My truck is a 2500 with the 68rfe.....which has both coolers (one cooler, one heat exchanger )

 

[Micsol]

Damn i didn't mean to start a major argument on here lol

 

[kthaxton]

Micsol, I suppose it is worth asking.....do you have any aftermarket accessories mounted up front that might limit airflow? Seems an unlikely concern since the trans cooler is in the upper portion of the front end...but its worth asking.

 

[Micsol]

No truck is bone stock

 

[Micsol]

I took it out yesterday on a 60 mile run all pretty much flat and the trans leveled out at 195-197. And the first 30 miles never hit 180. So I don't know. Maybe running through the mountains while they're not large mountains still do have some grades. Maybe this is the difference in temp


Ambient air temp was 60 degrees