[h018871]

GA_ZL1
Apologies that I don't answer your question of where in Atlanta to get your trans properly serviced.
Anyway, I hope the below helps you understand what's going on.
Most of what's been posted is correct, some less so.
Below is from my experience and what I've learned from others. Take from it as you will

I have a regular ZL1, you have the 1LE variant. That gives you the better, for tracking, trans pan. More on that in a bit.

Short version: Heat needs to be reduced, engine oil is the hottest. Since they all share the engine coolant, if one system is high it effects all of them. Add an engine oil cooler.

Long version:
The A10 is fantastic on the track, I manual shift mine all the time in the TX summers.
Bone stock the car was great although the oil temps got to 300F fairly easily and all of the temps were high.
First I switched to M1 15w50, this helped a little and the oil life did not drop as quickly.
Next was to swap the thermostat to the Katech 174F, you can do this without a tune change. Again a slight improvement, but not fixed.
The ZLE's trans pan has a shorter "fluid level pipe" in it when compared to the regular ZL1 and SS pans. This means it runs less fluid, which reduces foaming of the fluid, aerated fluid doesn't cool as well. This shouldn't be an issue for you, I don't think that fluid level is your problem since you have the ZLE pan. They'd have to way overfill your trans for that to be an issue. However GM did come out with a tech bulletin stating that the transmission is not to be "flushed" it is to have a drain and fill only. Most dealers push the flush anyway. It is critical that the all of the trans fluid be at the specified temp when the level is checked and the car should also be level. I did switch to the ZLE pan.

Back to overall cooling. The engine oil, trans and therefore the differential are all cooled or at least partially cooled by the engine coolant. the hotter the engine coolant the less heat can be removed from the other fluids. The trans seems to be the first to suffer from high heat
I saw Travis Lambert's post about the C&R, now PWR, aux oil cooler and SC intercooler.
here: https://www.camaro6.com/forums/showthread.php?t=583742
This is a pricey fix, he did a great job of documenting the changes in his oil, water and SC temps. I bit the bullet and got one of the early kits and installed the same as he did. The oil temp dropped 40-50F, water temps dropped to where they rarely get above 210F and the trans temps are now 200F.
Rapid_blue_zl1_22 did a different, less expensive install by placing the oil cooler on the passenger side and not changing the SC intercooler. He also removed the engine oil heater/cooler so that the oil is no longer cooled by the engine coolant.

Add an engine oil cooler

I searched GM performance shop Atlanta GA and got several suggestions. Call them and talk to them about your issue and what they think. Pick one that addresses your problem without trying to sell you "other things while they're there", go look at their shop. Good luck

[Stephen12ZL1]

the tranny is definitely overfilled and hopefully has the correct fluid in it. The techs are lazy and get it "close enough" and don't get the temps high enough to bleed off the correct amount. You can do it at the track but you have to be careful and wear gloves...the hot fluid is no joke so be careful. I personally have adjusted standard ZL1 fluid levels on 3 different cars at the VIR garage. Two of them the fluid level wasn't correct from the factory which isn't surprising...overfilled.

Manual vs auto shifting (no matter what GM says) is simple...more shifts equals higher transmission temps and less shifts is cooler. At VIR "A" mode shifts and downshifts many more times than paddle shifting making temps soar. I also have an opinion about 15w50 causing the oil temps to be higher from parasitic drag of the oil pump. Stirring that molasses is tough for the oil pump and makes oil temps 20° warmer in my experience. I use Motul 5w40 competition and it has worked great.

For tranny fluid I have been using Amsoil fluid (signature series fuel efficient) which is appropriate/approved for the 10spd with success. It comes in squeeze bags and makes it a breeze to place the fluid through the necessary port.

Hopefully some of this helps and I wish you success getting your temps down!

[GA_ZL1]

Thanks for the info. I am beginning to wonder if it is a general over-heating issue. I had a 2018 ZL1 1LE M6 before my 2023 ZLE A10, and I never had any overheating issues (oil, coolant, or tranny). The A10 seems to be another animal. How does one diagnose a water pump issue?

Alternately, I might just shift manually next time out and bit below red line to see if I can reduce the number of shifts and time running wide open--and hopefully run cooler all around. I was at Road Atlanta, which has some really long straights you run with WOT that taxes all cooling systems. Still, I'm disappointed given my prior experience with the ZLE M6.

Originally Posted by chevroletman

This may not be related but I had issues with my 2019 ZL1 1LE getting hot - coolant 280ish and 300+ oil temps- car was completely stock. dealer tried to help, but couldn't duplicate problem, of course. dealer changed t-stat bled intercooler ect. same issues. I was lucky enough to have my PDR data from the 2017 ZL1 i had previous to compare with, showed dealer data from same track under same conditions. GM engineering and dealer were stumped ( car had only about 1500 miles on it at this time). long story short I determined that holding the engine at high RPM, above 5300 of so, for longer periods would cause temps to climb. So for example in a long sweeping turn with trans shifting on it's own and holding RPM at say 6000 temps would climb. Did some of my own testing and drove a mile down the highway holding RPM at 6000 no load on engine temps went up 15+ degrees on coolant in 1 mile at 60 mph. So I determined that coolant temp was RPM related. Dealer ended up changing the water pump and problem was solved. After my coolant temps stayed manageable around 225 trans is running cool and shifting issues are gone. Oil temps now stay around 260. Again sorry for the long post

[GA_ZL1]

Thanks again, Slurpee!!! I just realized that you have ZL1 in A10 but not the ZLE like mine. Doesn't my ZLE ready have extra radiators for cooling? Disappointing, given I never had this issue with my 2018 ZE M6 overheating the oil, coolant, tranny etc.

Originally Posted by Slurpee

I do not believe this is ATF temp related....I believe the only remedy to this is to reduce engine oil temperatures, either by adding an air oil cooler...

[GA_ZL1]

Geoff: Thanks for the detailed, thoughtful response. I have been taking my ZLE to a really good speed shop in the North Atlanta area, and they did my last tranny change and bleed. They tune GM cars and know ZLEs, so I trust them. Maybe I'll ask them to check and bleed the coolant again one more time before my next track event.

Given your and the other informative responses, I'm leaning toward the following conclusions:

1) The ZLE A10 just produces more heat than a ZLE M6 (my 2018 ZLE M6 NEVER overheated any fluid). There may be some fixes or moderating approaches to the A10 heat, as you and other have suggested, but I suspect this may be something I will just have to deal with.

2) I'm going to try shifting manually at my next track day at Road Atlanta. The old GM 2019 Bulletin (see attached) said one should NOT shift manually because it would promote overheating, but I wonder if that is still their stance? I imagine that by me shifting manually (maybe a little short-shift of 300-500 rpm short of red line?), I will reduce the number of up/down shifts and reduce the excessive heat?

I'll report back after my next Road Atlanta event in June.

2019 ZL1 1LE A10 bulletin.pdf

Originally Posted by h018871

GA_ZL1
Apologies that I don't answer your question of where in Atlanta to get your trans properly serviced.
Anyway, I hope the below helps you understand what's going on.
Most of what's been posted is correct, some less so.
Below is from my experience and what I've learned from others. Take from it as you will

I have a regular ZL1, you have the 1LE variant. That gives you the better, for tracking, trans pan. More on that in a bit.

Short version: Heat needs to be reduced, engine oil is the hottest. Since they all share the engine coolant, if one system is high it effects all of them. Add an engine oil cooler.