Chevy Max Trans Temp

[TitanMike]

Originally Posted by babock

My Ford F-150 keeps the temps right over 200. That was it was designed to run at with its newly designed fluid.



I need to call up my old buddies at the GM transmission group and ask them why they did it too. BTW, many newer transmission's ECU controls the shifting based on temperature to change how the transmission shifts as its warming up. Not sure I would prefer to alter what their design intention was.

I enjoy reading how some are certain they can do a better job than the vehicle engineers who have all the education, millions of dollars worth of test equipment, and thousands of hours of test data that goes into their decisions to build it the way they do.

Then again, it's there vehicle and they can do what they want.

[babock]

Originally Posted by TitanMike

I enjoy reading how some are certain they can do a better job than the vehicle engineers who have all the education, millions of dollars worth of test equipment, and thousands of hours of test data that goes into their decisions to build it the way they do.

Then again, it's there vehicle and they can do what they want.

On the Ford forum, there was a long discussion on how to permanently disable the engine stop start feature when you come to a stop. One genius decided he would start pulling connectors below the dash until he disabled it. Of course he has no idea which control module he has now disabled along with the stop start mode.

[TitanMike]

Originally Posted by babock

On the Ford forum, there was a long discussion on how to permanently disable the engine stop start feature when you come to a stop. One genius decided he would start pulling connectors below the dash until he disabled it. Of course he has no idea which control module he has now disabled along with the stop start mode.

Around the office we had a saying for people like that ---- "bubba knows best"

[AlaskaErik]

Originally Posted by Crusadernoob

Optimal temperature range is something between 190-210 IIRC. Too cool is not any better than too hot.

That's right where my 2016 Silverado with 5.3 and six speed is at. Lower end during normal ops, middle when towing on flat ground and higher end when towing uphill.

[AlaskaErik]

Originally Posted by babock

On the Ford forum, there was a long discussion on how to permanently disable the engine stop start feature when you come to a stop. One genius decided he would start pulling connectors below the dash until he disabled it. Of course he has no idea which control module he has now disabled along with the stop start mode.

autostopeliminator.com if you have a Ford F-150 or GM 1500.

[babock]

Originally Posted by AlaskaErik

autostopeliminator.com if you have a Ford F-150 or GM 1500.

I just use Forscan and set the auto stop start to disable for my Ford. Basically free and is the most elegant solution.

[MR.M]

Originally Posted by TitanMike

I enjoy reading how some are certain they can do a better job than the vehicle engineers who have all the education, millions of dollars worth of test equipment, and thousands of hours of test data that goes into their decisions to build it the way they do.

Then again, it's there vehicle and they can do what they want.

Because we know the vehicle engineers get it right all the time and the first time . the T-stats help get the fluid up to temp quicker then with out . Chevy has them in their 1500 line up 6 speeds and 8 . the HD's do not use T-stats in the trannys 6speed . guess they figure hauling will keep temps where they need to be along with the cooling lines and all the great aftermarket add on coolers for transmissions . I do know with 197,000 on my 2500 hd keeping the temps when towing at around 165 hasn't hurt anything 145 when not towing . but maybe 197,000 just isn't long enough to determine if lower tranny temps hurt . some of the newer transmissions with their special fluids may require different temp perimeters . but it's not across the board and this is about chevy max trans temps and most are towing with 2500 or bigger not the 1500's

[67L48]

Originally Posted by AlaskaErik

autostopeliminator.com if you have a Ford F-150 or GM 1500.

For GM, which is what this thread is supposed to be about, then that may be a good option.

For Ford (how did we start talking about Ram and Ford in a Chevy Max Trans Teamp thread?), then definitely not. It's $90+ and a complete waste of money. For $18, you can get an ODB II USB device and use the free FORScan program to turn it off ... and do a bunch of other cool things in your truck's interface (like turning off annoying event-driven chimes/honks).

[dannko]

not related to Chevy, but what do you think if mine Cummins/Aisin runs in the 160's? Changing needed often or should get long life from the fluid?

[67L48]

[Mad Cow]

One can mitigate the events that cause hight temps with trans fluid. One is keeping the trans in manual mode to eliminate constant gear hunting on hills under a load if the trans is allowed to use all the gears.

What follows is based on my 2018 2500 6.0 gasser automatic with 4.10 diff ratios.

For instance, if I am towing heavy and am running rolling hills, I will generally keep the manual selector in M5 and not allow the trans to go to M6. This way, the rpms are up already for the next hill pull (without screaming RPM's) and the engine and trans are at optimum power band for the pull. If I left the trans in Auto and allowed it to go to 6th on it own, once it started loosing momentum it would drop to 4th or even 3rd and put the RPM's on the roof to compensate. That creates an inordinate amount of shifting all the time and that can really ramp up the heat.

I may manually allow the trans to go to 6th on a nice easy stretch, but before the next hill, I will drop the gear and get things ready for the pull. Else the Auto will be pegging several gears trying to get the right one.

Also, by keeping the transmission shifting to a minimum as much as possible also keeps torque converter clutch lock up in place longer. That greatly reduces heat generation in the transmission also.

I sometimes will even go as low as M4 if I am on two lane rolling hills where the speeds are lower than freeway speeds. One has to use a little judgement. But suffice to say, I never get temps anywhere close to the limit as expressed at the start of this thread or the link provided by the OP. And it centers around keeping automatic transmission shifting to a minimum and lock up at a higher percentage of time.

[stealth2715]

Originally Posted by TitanMike

I enjoy reading how some are certain they can do a better job than the vehicle engineers who have all the education, millions of dollars worth of test equipment, and thousands of hours of test data that goes into their decisions to build it the way they do.

Then again, it's there vehicle and they can do what they want.

What you're missing with your hundreds of engineer test hours and millions of dollars theory is that the product development targets are not always what you think they are. Many times the design suffers in performance to meet cost and legal targets. What this means is that you can modify to get better performance. like reducing heat to increase longevity if you tow a lot. Many people modify or remove the T-Stat on GM's with no ill effects. The smugness some of you display in your own enlightened opinions over those still willing to think for themselves only displays your ignorance.

[DieselDrax]

Originally Posted by stealth2715

What you're missing with your hundreds of engineer test hours and millions of dollars theory is that the product development targets are not always what you think they are. Many times the design suffers in performance to meet cost and legal targets. What this means is that you can modify to get better performance. like reducing heat to increase longevity if you tow a lot. Many people modify or remove the T-Stat on GM's with no ill effects. The smugness some of you display in your own enlightened opinions over those still willing to think for themselves only displays your ignorance.

Speaking of t-stats, did you know that removing them can actually cause overheating? Yup, it’s true. They regulate flow in addition to temp.

Not to say there aren’t vehicles that would run cooler without one, but sometimes doing something has the opposite effect of what you would expect.

Nothing wrong with thinking for yourself as long as you have an understanding of the logic/physics behind it.

[babock]

So what design constraints and tradeoffs did the engineers use to put in the thermostat?

Originally Posted by stealth2715

What you're missing with your hundreds of engineer test hours and millions of dollars theory is that the product development targets are not always what you think they are. Many times the design suffers in performance to meet cost and legal targets. What this means is that you can modify to get better performance. like reducing heat to increase longevity if you tow a lot. Many people modify or remove the T-Stat on GM's with no ill effects. The smugness some of you display in your own enlightened opinions over those still willing to think for themselves only displays your ignorance.

[Mad Cow]

I am not convinced that there were any short cuts or design flaws. It is far easier to convince me that there are operator flaws.

[TitanMike]

Originally Posted by Mad Cow

I am not convinced that there were any short cuts or design flaws. It is far easier to convince me that there are operator flaws.

So true. However it's darn near impossible to convince the operators that they are often the "flaw".

[MR.M]

Originally Posted by DieselDrax

Speaking of t-stats, did you know that removing them can actually cause overheating? Yup, it’s true. They regulate flow in addition to temp.

Not to say there aren’t vehicles that would run cooler without one, but sometimes doing something has the opposite effect of what you would expect.

Nothing wrong with thinking for yourself as long as you have an understanding of the logic/physics behind it.

Engine T-stats are one thing . transmission t-stats another . just because they put them in some transmissions does not mean removing them will cause over heating . they were installed to bring the tranny up to temp faster . not a problem towing and since this is only in the chevy 1500's not the hd trucks . and others brands who knows and don't care

[DieselDrax]

Originally Posted by MR.M

Engine T-stats are one thing . transmission t-stats another . just because they put them in some transmissions does not mean removing them will cause over heating . they were installed to bring the tranny up to temp faster . not a problem towing and since this is only in the chevy 1500's not the hd trucks . and others brands who knows and don't care

Yes, that is true, just pointing out that reality and expectations aren't always the same. Some trans fluid is designed to have the correct properties within a certain temp range or above a certain temp, thus the use of t-stats for transmission coolers. Overcooling COULD result in improper or hard shifts because the fluid isn't performing per spec. Could also result in extreme overcooling if you live where it's very cold and the fluid may be unable to get anywhere near minimum operating temperature. I expect this would result in more drivability-related issues than technical issues that would damage the transmission, but I'm not an transmission engineer so that's just a guess.

The bigger theme I see across the board has to do with folks set in their old ways and thinking the old ways are better, such as cooler trans temps are better, higher viscosity oil is better, leaf springs are better for heavy loads, and so on, so they modify their modern vehicles to try and have them operate in ways they weren't engineered to, creating problems when the original setup was working as designed and there were no problems.

This phenomenon goes beyond vehicles, my brother has messed up his computer lord knows how many times because he constantly runs 3rd party tools to try and fix problems that don't exist and those tools end up causing him problems, so he looks for a tool to fix the problem the other tool created and the cycle continues. Had he just left things alone and didn't try to find solutions for non-existent problems he wouldn't be in that situation.

If there's a legitimate deficiency with how something was designed then by all means look for a solution, but don't make changes just because you think you know better than the engineers and think the new normal is wrong and causing problems. That's all.

[TitanMike]

Originally Posted by DieselDrax

The bigger theme I see across the board has to do with folks set in their old ways and thinking the old ways are better, such as cooler trans temps are better, higher viscosity oil is better, leaf springs are better for heavy loads, and so on, so they modify their modern vehicles to try and have them operate in ways they weren't engineered to, creating problems when the original setup was working as designed and there were no problems.

If there was an award for "Hitting the Nail on the Head" I think you should get one for each of the situations you pointed out!

You definitely made a direct hit

As for the "Cold" part, I traveled to Alaska during my working career, often during the winter. Picking up a rental car in Fairbanks usually went like "Go out and find your car. Start (or at least try) your vehicle and store the engine heater power cord in a coil hanging from your rear view mirror. Go back into the terminal and have breakfast. Come back and scrape the rest of the frost off the windows/windshield. Put engine in gear, let idle for a few minutes, shift to reverse and repeat. Once you felt transmission shift like it should then go ahead and drive away. Outside temp during this? About -50 F and MAYBE rising to - 35 around noon (with little or no sun).

That's probably why some vehicles have thermostats in their tranny's today. The mfr sells vehicles that are used in Alaska and Northern Canada and once the fluid has heated the thermostat is just "there".

[stealth2715]

back when there were no t-stats in trannys plenty of them burned up, I know because I was there seeing the poor schleps paying for rebuilds. I burned one up myself bolting a turbo 350 to the back of a 454 in an impala with no trans cooler. After that everything got a trans cooler and guess what happened? absolutely nothing. I have never burned another trans since and never worried it would be too cold to work properly because it always just did. The t-stat is there on a GM 1500 to get the fluid hot quicker, Hot fluid will save a few drops of fuel and bump the MPG up a fraction of a percent. The design target was weighted toward efficiency on a model (1500) that is a commuter much of the time. A 2500 is designed to tow/haul, ...people commute with a trailer attached or monster truck out so more heat is the last thing they need. Go to the Chevy truck forums and look around. There are thinkers that have painstakingly documented temperature plots over the same road with the same load from stock to modified t-stat to none. running too cold is not a problem and overheating will just never happen with the t-stat removed. And operating temps are much reduced. FWIW I haven't yet modded my 1500 trans T-Stat. I got the dreaded chuggle at 25k and if it happens again at 50k I will pull it. Seen temps ~235 in manual mode, tow mode didn't matter. Heat is not your friend.