Max Chevy Trans Temperature

Doesn't the Allison/gm go into limp mode and de-fuel when trans overheat occurs?
The 08 duramax for sure has the cooler mounted underneath the truck and just ahead of fuel tank..
I wonder how optimal that is ?
I've been looking for a small shrouded fan to mount on it but its a pretty small cooler@ 8-1/2 by 10-1/2.

Turbs

that is a fuel cooler, not trans.. my engine code is not reliant on this cooler but the LLY is because your FICM is cooled with fuel, no fan is required on any trucks at this cooler
 
Last edited:
that is a fuel cooler, not trans.. my engine code is not reliant on this cooler but the LLY is because your FICM is cooled with fuel, no fan is required on any trucks at this cooler

My bad your right.
I thought I traced the lines.
6 two many buds I guess.
 
Good info!

Thanks Lou. I asked my dealer service department what the max temp was when I bought the truck and they did not know. They "thought" 220 was max. I did not know until your post that the DIC gives an alarm at 250. That is good to know. On our trip to Big Bend last spring I had a long climb into a strong headwind. The trans temp got to 216 and worried the heck out of me. Knowledge is good, thanks again.

I am glad to learn this as well. While pulling my 25ULA behind my (now replaced) RAM 1500 HEMI I had trans temps get above 210 on a couple of occasions and it concerned me. On one trip through west Texas, on a long grade it got to 217 and I too was sure I had done damage - now I know while it wasn't good, no significant damage was probably done.

Transmission concern was one of the reasons I upgraded to 3/4 ton CTD.

Good info all around.
 
I recently bought a 2008 Surveyor SV-291 that I'm towing with my 2006 Yukon XL.

This truck is (from an power train perspective) a Chevy 1500. 5.3l V8 flex fuel with a 4l65e Transmission.

I added a 40k GVW transmission cooler and a ScanGauge II to monitor the transmission temps. Prior to the cooler I sat around 176F, after the transcooler the truck barely gets over 125F while pulling. It gets up to about 190 (highest I've seen it go) when the truck is idling for 10+ mins. This is a result of the fluid being warmed up as it passes through the radiator by the engine coolant.

The faster you go the lower the temps it seems, even when pulling up grades the temp does not climb hardly at all. I'm very happy with the unit, it replaced the factory tow package cooler, and will hopefully provide a longer life for my 4l65e.

I also put some lucas oil severe gear 85w140 in the rear diff, and replaced my track bar bushings and the truck tows beautifully when the Reese hitch and 1200lb bars. I'm really impressed. I was very afraid that I was going to end up wanting to buy a heavier duty truck because I would be "white knuckle" driving with a 1/2 ton
 
I recently bought a 2008 Surveyor SV-291 that I'm towing with my 2006 Yukon XL.

This truck is (from an power train perspective) a Chevy 1500. 5.3l V8 flex fuel with a 4l65e Transmission.

I added a 40k GVW transmission cooler and a ScanGauge II to monitor the transmission temps. Prior to the cooler I sat around 176F, after the transcooler the truck barely gets over 125F while pulling. It gets up to about 190 (highest I've seen it go) when the truck is idling for 10+ mins. This is a result of the fluid being warmed up as it passes through the radiator by the engine coolant.

The faster you go the lower the temps it seems, even when pulling up grades the temp does not climb hardly at all. I'm very happy with the unit, it replaced the factory tow package cooler, and will hopefully provide a longer life for my 4l65e.

I also put some lucas oil severe gear 85w140 in the rear diff, and replaced my track bar bushings and the truck tows beautifully when the Reese hitch and 1200lb bars. I'm really impressed. I was very afraid that I was going to end up wanting to buy a heavier duty truck because I would be "white knuckle" driving with a 1/2 ton

Blackseven: does your truck have the same interior as a chevy pickup truck??????

Nevermind, just noticed its a 2006;)
 
Has anyone else noticed that the manufacturers are running higher temps in the new transmissions? The six speed in my 2015 Silverado runs 195 to 200 degrees wether I am towing or not, no matter the outside air temperature (it just takes longer to reach 200 in the winter). The only logical explanation I have heard is that the warmer fluid flows easier increasing the efficiency of the converter and the gear train as well.
 
That's about what my 2010 ran when daily driving - I added an additional cooler and now it is around 170 although that fluctuates more depending on ambient air temp.
 
Turbs, that cooler is for diesel fuel. For the return. To cool down the fuel going into the fuel tank. It's not a transmission cooler. Jfyi.
 
Has anyone else noticed that the manufacturers are running higher temps in the new transmissions? The six speed in my 2015 Silverado runs 195 to 200 degrees wether I am towing or not, no matter the outside air temperature (it just takes longer to reach 200 in the winter). The only logical explanation I have heard is that the warmer fluid flows easier increasing the efficiency of the converter and the gear train as well.


The newer transmissions are thermostat controlled, you could have a cooler the size of the bed in my truck and it will still be 195F loaded or not.

I guess, according to that chart, my trans will only be good for 85K miles?? :roflblack::roflblack:
 
The newer transmissions are thermostat controlled, you could have a cooler the size of the bed in my truck and it will still be 195F loaded or not.

How do you explain the noticeable drop in my tranny temps after adding an additional cooler? It is the newer 6L80 used in the Caddy/Chevy/GMC truck lines.
 
How do you explain the noticeable drop in my tranny temps after adding an additional cooler? It is the newer 6L80 used in the Caddy/Chevy/GMC truck lines.


Sorry bubba! I did not notice until just now that this was about Chevy, I am a Ford guy, I know nuttin about Chebby, please disregard.
 
It would be odd if Ford now regulates the minimum tranny temps. All the research I did before I added my additional cooler says that you can't cool a tranny too much. The lower you go, the longer it lasts.

With the bitter cold now in place I kept an eye on my temps yesterday and today. At highway speeds it hovered around 100 F once it was fully warmed up, plus or minus a few degrees. It slowly warmed while stopped. I wish I could maintain that temperature going up a steep slog!
 
Just to add another point of view, I have a 2014 1500 silverado v6 long bed. My tt is a same year canyon cat 17qbc. TT weighs in at about 4000-4500 loaded. I watch my trans temp and the highest it has ever gotten is 207%. That was in very slow almost stop and go traffic for about 45 minutes. It normally runs about 198 or so when towning level or to speed.
 
It would be odd if Ford now regulates the minimum tranny temps. All the research I did before I added my additional cooler says that you can't cool a tranny too much. The lower you go, the longer it lasts.

With the bitter cold now in place I kept an eye on my temps yesterday and today. At highway speeds it hovered around 100 F once it was fully warmed up, plus or minus a few degrees. It slowly warmed while stopped. I wish I could maintain that temperature going up a steep slog!


Well, they are not regulating a minimum temp, it is not like they add a heater to the cooling circuit, the tranny will do it, even if it takes a while in very cold temps. The thermostat in the Ford 6 speed torqeshift does not even send fluid to the cooler until it reaches 190F. It also will not go into 6th if the temp is too low, viscosity rules inside a hydraulically actuated machine that is a transmission. I would imagine GM also uses some sort of thermostat as well. I am sure dodge uses duct tape and popsicle sticks... :roflblack:
 
Well, they are not regulating a minimum temp, ...The thermostat in the Ford 6 speed torqeshift does not even send fluid to the cooler until it reaches 190F.

That's what regulating the minimum temperature means. Without a thermostat the minimum temp will go lower as the ambient temp drops. With the thermostat the fluid is retained until it gets up to 190.
 
I think we are at two different angles on the same problem...

Have a good one!
 
If your truck is a Chevy the DIC information center will tell you if you have exceeded maximum transmission temp.
 
If your truck is a Chevy the DIC information center will tell you if you have exceeded maximum transmission temp.
Might even go into limp mode.

TURBS
08 duramax tuned n modded, 32bhok Sabre
 
I would imagine GM also uses some sort of thermostat as well. I am sure dodge uses duct tape and popsicle sticks... :roflblack:

Now that's funny! [emoji12]

TURBS
08 duramax tuned n modded, 32bhok Sabre
 

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top Bottom