Transmission temperature 10speed with 3.0 LZO Duramax

[repairman54]

23 hours ago, Grover67 said:

repairman54 do you have the Max Tow package?

 

-grover67

No just the standard tow package in a Z71

[LuvGinger]

Yes. Those are normal Temps.

 

I installed a PPE Trans Cooler, PPE Thermal Bypass, and PPE larger capacity Transmission Pan. Best thing I ever did. Transmission runs 130 degrees and never really deviates from that. When I stop cools a few degrees immediately.

 

[MrMagloo]

Just wondering out loud, at what point is the trans temp too cool?  I've read a lot of varying opinions, some suggesting you need to get at least into the 170-180 range on these new 10 speeds?  I've never heard of a trans running at a normal operating temp of 130.

[MrMagloo]

delete

Edited September 22, 2023 by MrMagloo
Dupe

[mjonesjr84]

49 minutes ago, MrMagloo said:

Just wondering out loud, at what point is the trans temp too cool?  I've read a lot of varying opinions, some suggesting you need to get at least into the 170-180 range on these new 10 speeds?  I've never heard of a trans running at a normal operating temp of 130.

I had a 2023 Silverado with the 5.3 and 10L80 10-speed for a rental earlier this year. The transmission temperature stayed between 130-140 at all times. It is the same 10L80 that is in the 3.0 Duramax trucks. 

 

I will keep my PPE cooler and PPE bypass valve in. 190+ temperatures are not good for a transmission.

[MrMagloo]

It's an interesting discussion as this vehicle is definitely running higher than what my past trucks used to run.  I've actually driven a number of 2021's through 2023's and they all ran in the 185 to 195 range. This seems to be the factory target.  Definitely not a range I'm comfortable with. 

Edited September 20, 2023 by MrMagloo

[Pbeau84]

I have a '23 Silverado RST 3.0. Normal Trans temps are 180-205, really varies a lot sometime while towing I'm below 180 and sometimes driving with no load I'm 200, weird. But I noticed when I'm parked, either idle or in park the temps can jump pretty quick. I was in a parking lot and just wanted to see where it would level off and got to almost 230 before I started driving again. Anyone know if this is normal? Ambient temp was only 59 degrees so not hot. It just didn't see like the temp was going to level off, just kept creeping. 

 

Any help appreciated.

[Pbeau84]

26 minutes ago, Pbeau84 said:

I have a '23 Silverado RST 3.0. Normal Trans temps are 180-205, really varies a lot sometime while towing I'm below 180 and sometimes driving with no load I'm 200, weird. But I noticed when I'm parked, either idle or in park the temps can jump pretty quick. I was in a parking lot and just wanted to see where it would level off and got to almost 230 before I started driving again. Anyone know if this is normal? Ambient temp was only 59 degrees so not hot. It just didn't see like the temp was going to level off, just kept creeping. 

 

Any help appreciated.

Spoke to one dealer and said not an issue until 260-270 and that its normal 

[redwngr]

Mine runs 190-200.

Colder weather it takes longer to get there.

 

The idling scenario wouldn't bother me at all. 

 

 

 

[Rick_]

My wife's '22 RST 3.0 with our 5000lb boat running 70mph in rolling hills at around 3000ft in low 90's temp runs up to 201* even with the Max Trailering package.  Looks like it's going to get the PPE bypass.  My '24 3500 Duramax barely cracks 150* with the same boat running between 70-75mph.  

[redwngr]

That's seems to be where GM wants them to run 190 -200. 

Probably also why they use a different fluid than the 8 speed, which has a different fluid than the 6 speed.

 

Mine does those temps winter or summer, lightly loaded or heavy.

 

I does take longer to reach that temperature if lightly loaded in cool weather. 

Once it does get to that range it does not increase any more (winter or summer, lightly loaded or heavy).

There must be a fair amount of bypass flow when the thermostat is 'closed'. 

 

 

10 speed in a 3500 is a different transmission and uses a different fluid. 

 

Edited August 14, 2025 by redwngr

[newdude]

22 minutes ago, redwngr said:

 

10 speed in a 3500 is a different transmission and uses a different fluid. 

 

 

 

All GM 10 speeds use the same fluid.  Dexron ULV p/n 19352619.

[Grumpy Bear]

On 9/20/2023 at 1:43 PM, MrMagloo said:

Just wondering out loud, at what point is the trans temp too cool?  I've read a lot of varying opinions, some suggesting you need to get at least into the 170-180 range on these new 10 speeds?  I've never heard of a trans running at a normal operating temp of 130.

 

I see we are neighbors. Good, then we have some common experience. How does the truck run on a -20 F winter day first start of the morning? Does is hang on to the 1-2 shift or the 2-3 a bit longer than when hot? Too cool. Then there are perhaps some parameters within the TCM or ECM that require a certain temperature to satisfy some requirement or another. Too cool. 

 

Now I don't own an Allison 10 so don't know it's programing but I'd still wager that the temperature in which ALL requirements are satisfied for 'normal' operation is something like 105-115 F AFT temperature. My 6L80E is 107 F. 

 

Anything between that trigger number and 'too hot' is a sound operating temperature. Too hot is over 175 F and will be for every transmission that uses hydrocarbon lubrication. So 120 F to 175 F is target. (120 F to 160 F for older boxes still using full conventional fluids). 

 

That doesn't mean the OEM designed it to operate in that area. Wear is not their first priority. Fuel economy and cost take priority over wear as long as wear keeps them out of the warranty claim box and they don't mind loosing a certain percentage of them even to that. Bean counters are not engineers and even engineers are subject to bosses whose priorities are not the consumer they sell to but the shareholders they placate. 

 

Anyone that tells you that 120 F is too cool and will accelerate wear is full of Internet regurgitated . Anyone that tells you that running over 175 F continuous will not shorten the life of the fluid/gearbox, ditto. 

 

There isn't any Kryptonite seals or clutch bonding materials saved only for Allison and no Unobtainium fluid that will take the heat of the sun. 

 

Does this mean that a box running 215/225 F is doomed? Not necessarily. It means the owner/operator will need to be more diligent about fluid exchange and live with less cushion for that long grade or silly hot day. 

 

 

Transmission life follows fluid life and the fluid doesn't know or care what box it is in.

 

 

This information originally came from Kendal Oil and has been displayed two dozen different ways by every Internet concern there is; often corrupted to read transmission life and not fluid life. 

 

You may notice that the OEM temperature range and the fluid change intervals come pretty darn close to the chart. You will also notice that when they don't the warranty miles isn't all that. There is no 'forever fluid'. 

 

Do with this information as you please. It will have no effect on my equipment whatsoever.    

[PunchT37]

The cooler the trans the better. My 10L80 with NHT package stays 145`ish most of the time. That`s down here in the heat. I damn sure don`t want to run a ULV oil at 180 plus. Or, any ATF for that matter.

 

Show a bad trans that was removed because it "ran too cold".

 

Then, show a bad trans that was removed because it ran too hot.

 

Wonder how different those numbers would be?

[redwngr]

19 hours ago, newdude said:

 

 

All GM 10 speeds use the same fluid.  Dexron ULV p/n 19352619.

Thanks for the correction! 

 

Is there an Allison fluid that is also recommended?