Trans Temps Over 200 This Week, 100+ Degree Weather...

[Pool Runner]

Just like it says, I have a 6.0L 2500 HD 2wd "Work Truck" but it's a LT1 package. Anyway my truck has 18K miles YTD and I bought it brand new a year ago with 20 miles on it. Since I use this truck for work it's been loaded up with tools and such, I think I always have around 800+ lbs in the box at all times. Anyway this is my first summer with the truck, I work in areas where I pull steep grades in the country, and rural suburban areas, and quite a bit of stop & go in town. Since time is money, I am not easy on this truck but don't beat it. That's why I bought a Chevy and a Heavy Duty because I needed a truck that can take the day to day abuse and grind I throw at it.

 

Anyway last week I was doing a lot of stop and go and had to climb a few hills to get to some job sites and the temp in the mirror said it was 105 degrees outside and the DIC said my trans temp read as high as 208!! Also as soon as my trans temp got over 200 the truck felt noticeably more sluggish and I can tell the engine fan was on for a lot longer than usual. Anyway there were no warnings, and after reading the owners manual it says if the trans temp gets too hot and out of the safe range a warning will be displayed and the truck will go into a limp mode or reduced performance mode until temps return into the safe range. Anyway just wondering if something is wrong with my truck? or is this normal for the high ambient temps outside and the duty I am asking of my truck i.e. heavy load, not taking it as easy as I should etc....

[oldschool327]

208 is no worries. When you hit 230-250 is when the limp feature will kick in. Now 208 is not great and your fluid will degrade quicker than say under 180 but still nothing to worry about. Find a good cooler (B&M) like most have and be done with it for good.

[dewfpo]

What your seeing is normal. High temps, climbing hills, 800 lbs. of gear in the back will give you those tranny temps all day long. I see that with my 2005 Allison as well. GM doesn't the consider the ATF overheated until something like 265F.

 

The DexVI in your tranny should be able to handle it no worries.

 

DEWFPO

[06yz125]

My first post..YEA.

 

We have the same combo. Tow about 13,000# through the

West Virginia mountains and beyond. Just came from the

Ford 6.uh oh <smile> Before that we had an 03 chev 6.0 2500.

Good motor just not right for 13K.

 

We now have the 2010 chev 6.0 again. Much better with the

6 speed and 360HP. The tranny temp does get warm on ours.

I kind of worried til I talked to a chev tech who I believe. Just

change the fluid at 50K if you haul heavy. Even if you didn't

he said it would still last to 100K. Better safe than sorry though

since the warranty would be out by then LOL

 

Hey oldschool..USMC here too. Semper Fi.

 

But, this combo is awsome. Hope it lasts.

[oldschool327]

Where you stationed. I just PCS'd from Cherry Point to I&I Sacramento.

[06yz125]

Guess I should have said former Marine. I'm an old guy. My last duty station was

Quantico Virginia in 1985.

[Pool Runner]

Hey thanks guys, and thank you for your service! Another question although I should probably create another thread but I will save the bandwidth. Anyway I love this GMT900 truck to death, it's screwed down better than my old '05 Dodge w/ cummins diesel was *shrug* anyway, one thing I notice is when the ambient temp outside is over 100 degrees it feels like the truck has a boat anchor hanging off the rear bumper? In other words it just usually feels very powerful under normal circumstances, but as soon as the temps get over 100 outside the fan clutch is engaged and it feels like my trucks overall power is about 50% is this normal?

[oldschool327]

You should not have a fan clutch. It should be an electric fan. Look at the front of the engine and see if you have just a nut where the fan should be. The fan should be located up at the radiator. I have never had a problem with heat. NC summer with 100 degrees and 90% humidity and now it was 103 yesterday here in Sacremento and no problems either like you describe. Might warrant a look at the dealer. Should be under warranty still right?

[jhplak325]

He should still have a fan clutch since it is an HD, my 09 has a fan clutch and does the samething when the outside temp is close to 100 or over. I have also noticed as soon as the truck feels like it has a boat anchor dragging behind, trans temp is about 190.

 

I beleive the half tons are the only ones with electric fans, I know my 05 had electric fans.

[oldschool327]

Thats why I asked, never know what is under the hood anymore. Fan clutch would rob power and therefore feel different. Black Magic fans are a great way to fix that problem though.....Worked great on my 68 Stepside 327 Fuelie!