Chevy and GMC Duramax Diesel Forum banner

1 - 20 of 63 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
I have an ATS transmission in my 2008 GMC 2500hd duramax. This was in the truck when I bought it at 99k miles. It has 130k on it now. It was running hotter then I liked it to so I changed the fluid and external filter. Didn’t fix the problem so pulled the stock trans cooler and put in the PPE transmission cooler. Still no fix, not sure what to do next. Dip stick is hard to read so I made sure the fluid wasn’t too high. Even went by a trans shop and had them check the fluid levels.
Not sure what to do now. Any help would be great.
 

·
Premium Member
Joined
·
3,316 Posts
Welcome to the forum!! How hot is "hotter than I liked it"? Do you see high temps while in stop and go traffic? Are you sure the gauge is reading OK? Do you tow anything? Are you using an aftermarket grille? Have you tried cleaning the cooling stack? (search for how to). Is the dipstick tube fully seated? What year? Is it a 5 speed or 6 speed? Did the ATS trans replace a trans with burned clutches? If so, you might have burned clutch debris clogging the radiator heat exchanger.
You might provide some clues on what you have so folks can help figure it out.....
 

·
Registered
Joined
·
75 Posts
I have an ATS transmission in my 2008 GMC 2500hd duramax. This was in the truck when I bought it at 99k miles. It has 130k on it now. It was running hotter then I liked it to so I changed the fluid and external filter. Didn’t fix the problem so pulled the stock trans cooler and put in the PPE transmission cooler. Still no fix, not sure what to do next. Dip stick is hard to read so I made sure the fluid wasn’t too high. Even went by a trans shop and had them check the fluid levels.
Not sure what to do now. Any help would be great.
I believe it says 2008 which would be a 6spd..:surprise:
 

·
Premium Member
Joined
·
1,087 Posts
Built transmissions tend to run a little hotter correct? So what is the actual temp your talking about?

Sent from my SM-G977U using Tapatalk
 

·
Registered
Joined
·
7,248 Posts
What about the internal filter ?
Lasting a lifetime theory went out years ago.
What are the outside temps where your located, I’ll also throw in what are these trans temps running that your concerned about.
What fluid did you use? Did you contact ATS asking what fluid do they recommend.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #6
Well from what I read standard operating temp is 180-200 or 100 degrees over ambient temp. Yesterday it was 80 degrees and it got to 228 driving around town. Last weekend I ent up to the mountains where it was in the 70’s and 60’s. And going up the mountain it got to 240 and my programmer goes into defuel so I would pull over and let it cool down. I have the dash temp and the programmer reads temp as well. I don’t know if they read from the same spot or not. As for the transmission clutch debris I have no idea. I was told it was upgraded for towing. It is a 6 speed I used valvoline dexron 6
 

·
Registered
Joined
·
584 Posts
Well from what I read standard operating temp is 180-200 or 100 degrees over ambient temp. Yesterday it was 80 degrees and it got to 228 driving around town. Last weekend I ent up to the mountains where it was in the 70’s and 60’s. And going up the mountain it got to 240 and my programmer goes into defuel so I would pull over and let it cool down. I have the dash temp and the programmer reads temp as well. I don’t know if they read from the same spot or not. As for the transmission clutch debris I have no idea. I was told it was upgraded for towing. It is a 6 speed I used valvoline dexron 6
Most built transmissions use dex 3, you should contact ATS and confirm.
 

·
Registered
Joined
·
6,662 Posts
The biggest problem is its purple. Might be a blockage in a line to the cooler. Did you flush them when you changed the cooler? Could be the convertor isnt locking up as that will generate the most heat. Anyway to see if convertor is locking? Try driving in towhaul as the comverter will engage must sooner (between 2nd and 3rd usually vs 5th when not in towhaul).
 

·
Registered
Joined
·
10,129 Posts
If its had dex6 in it a long time that could affect the clutches. Being its from ats though i would guess its just the transmission itself, but i would do everything including running dex3 in it to make it last. Along with saying a prayer. Ive seen mike L say he wouldnt flush his toilet with dex 6, thats all i needed to hear to not run it in a built or stock allison. It will also ruin the seals in the older transmissions. Transynd in stock transmissions, dex 3 in built ones.
 

·
Registered
Joined
·
10,129 Posts
Do you have a deep pan on it by chance? Has it always ran hot or did this just begin? Did you change anything?
 

·
Registered
Joined
·
10,129 Posts
Where is the fluid on the dipstick?
 

·
Registered
Joined
·
7,248 Posts
If you haven’t yet, it might be a good idea to drop the pan to visually check inside if it’s clean or clutch material.
The fluid level is important.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #17
So I took it to a transmission shop today. What they said was:They drove it around, no TCC slipping at all the transmission runs perfect. But I had an accelerator pedal position sensor code. So I replaced it myself for 80.00 instead of paying there 180.00 in parts plus labor. They say this could help due to the computer getting the wrong signal from the APP and will not command the right gear or the TCC and get hot. We will see but I am not sure this will help. Next I guess drop the pan change the internal filter and maybe bypass my radiator.
 

·
Registered
Joined
·
10,129 Posts
With a deep pan fluid should be mid way of cold mark or bottom of hot when up to temp.
 
1 - 20 of 63 Posts
Top