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.....

 

I believe it says 2008 which would be a 6spd..:surprise:

 

Built transmissions tend to run a little hotter correct? So what is the actual temp your talking about?

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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.

 

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.

 

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).

 

I did not flush the lines but my programmer says when the TCC is on and the shop I took it too says it runs perfect.

 

ATS said I should run Dex 3 and up

 

Sorry ATF +4 and up

 

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.

 

Do you have a deep pan on it by chance? Has it always ran hot or did this just begin? Did you change anything?

 

I didn’t notice it running as hot on normal driving till this last summer. But maybe if I drop the pan I will go to dex 3 but ATS said 4 or above so not sure.

 

Yes it has a deep pan

 

Where is the fluid on the dipstick?

 

The fluid levels are a pain in the ass to read on my dipstick. Checked 15 times and had a transmission shop confirm so it was good and still is. Right at the lower hash marks on the hot side at 180

 

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.

 

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.

 

With a deep pan fluid should be mid way of cold mark or bottom of hot when up to temp.

 

I will maybe take a little out it is mid level in the hot hash marks at operating temp

 

Has anyone been passed there radiator and just used the trans cooler?

 

Trans fluid doesnt touch the radiator, just the trans cooler, so theres nothing to bypass there.2 lines come from the passanger side down the side of the block then up in fron of the radiator to the cooler.

 

Mike L is the resident trans guru. When theres a problem, he gives a no bs answer on the problem. One of the most knowledgable people on here when it comes to our allisons, just look around the tranny section.

I seem to recall Mike saying I could run dex 6 with my built trans, so its not that they cant or shouldnt run, just that most dont. Still, ive stuck with the dex 3 reguardless.

The cooler lines have nothing to do with TCC, they are there to cool the fluid, period. If you have a blockage in the lines to or from the cooler, fluid will get hot. There isnt a code to tell when that happens.

 

Trans fluid comes out of the converter into the heat exchanger within the radiator for the intial heat knock down. Then it goes to the cooler up front. Bypassing the radiator is a mistake and will cause trans over heat. The outside air to oil cooler cannot handle the heat by itself because there is no air flow below 35 mph.

 

Thanks for that update. Won’t do that then. Would you run dex 3 instead of dex6 in an ATS transmission and with the deep pan where should the level be at operating temp. Middle of the hot hash marks? Thanks for all the help.

 

I stand corrected. Thanks Mike.

 

What fluid to use 'dunno;, your question would be better to ask ATS, it was built by them.

 

They said dex 4 and up

 

Never heard of Dex 4.

 

This is what they emailed back to me.

all we require is the use of ATF+4 or better quality fluids)

 

ATF+4 is the fluid used in the Chrysler transmissions.

 

so I guess I should maybe go back to ATF 4 ? Not sure now what I need

 

Nothing unusual or scary about a trans temp of 240f, anything under about 280 is ok. In fact getting the oil above 212 is preferred as it gets rid of any water.

 

Wouldn't want mine that hot.

 

I have read the whole thread and I need to confirm it's the trans fluid temp and not the engine cooling temp. If in fact it is the trans fluid temp their is a definite problem. To confirm did you bypass the radiator trans cooler and are using only the PPE trans cooler. I have an 07 LBZ with a stg V built Allison and a Suncoast triple disc TC. Towing a 13K lb 5th wheel I usually run 85-90 deg over ambient outside temp. I had an eng cooling temp problem and fixed that but didn't want to hunt and peck what I did to correct it. I usually tow my 5er at 63-65 mph in 5th gear on the level 4 tune. No problems

 

It is the trans not engine coolant. Engine temp is fine. I have a brand new motor with only 8k miles on it now.