[Canadian ZL1]

So I am hoping I can get some good advice. Let me set the stage first.

I managed to book a track event in Bowmanville Ontario (2,459 mile 10-turn road course).

As part the prep I had DOT 4 Motul brake fluid, the Transmission fluid was changed the year before as well as the Rear Differential and of course put fresh 0W40-Mobil 1 oil in her.

The weather conditions were a gorgeous 65F which are very ideal for any supercharged cars.

I have the A10 and it should be noted I like to use the paddle shifters when I am on the track. Everything was going great and I had the car on the track for 4 sessions each lasting approx 20 mins.

My fifth session I decided to keep the car in D this time and let it shift for me. My first observations was it obviously liked to hold the gear longer and personally it was not as engaging compared to using the paddles. Towards laps 6 & 7 I noticed the car was hesitating and or the shifts started to feel clunky and not as smooth.

Then all of sudden the car started to chime and I received the message on the dashboard "Transmission Temperature High, Idle Engine". I pulled over immediately and turned off the car. Fortunately for me it was right near the pit lanes and so I was able to pull over safety. I looked underneath the car and a small pool of fluid (transmission fluid) was leaking.

My day was done and to be safe I ended up having the car towed to the dealership. It turns out I could of been able to drive it to the dealership but I wanted to be safe rather than be sorry.

Since I recorded the session with my PDR I was able to pull some interesting stats from the GM Cosworth Toolbox (see pictures below). Note the Max Transmission Oil Temp reached 280 F and this was on Lap 7 where I received the chime/alert of high temp. While I was on the track I did not have the data displayed in terms of oil & transmission temp. For next time I will be sure to have this visible.

The dealership is unable to tell me why the temperature reached as high as it did. They did tell me there is an insulator the engineers are requesting gets replaced as is has been saturated with fluid due to the excess heat. There is a fire hazard with track use if this not replaced.

I have an amazing dealership and of course this will be covered under warranty.

My only problem is I still don't why this happen?

It should be noted that the transmission fluid was not over filled or under filled and in terms of traffic on the road course it was minimal and so lack of air (cooling) was not a problem while on the track.

My question is when they fix the problem for me has anyone elected to upgrade the transmission fluid from the stock GM stuff to an aftermarket or higher grade? My thinking was like I did with the brake oil (moving from a DOT 3 to DOT 4), if I apply the same theory in terms of upgrading to a higher tranny transmission oil might that solve my problem?

If you are still reading this I hope I might get some suggestions on how to prevent this from happening again. All in all I still had a fun day and love this car!!!!!

[SFV1LE]

Overheating like that on a 65 F day is strange. Haven't kept track but I believe there have been some reports of this.

[Stephen12ZL1]

fluid level is likely too high & huge difference in temps in my car with the tranny in "D"...use the paddles as the car is very busy upshifting and downshifting a lot causing the fluid to overheat. Was the correct ULV fluid used during your previous service visit?

[Canadian ZL1]

Originally Posted by Stephen12ZL1

fluid level is likely too high & huge difference in temps in my car with the tranny in "D"...use the paddles as the car is very busy upshifting and downshifting a lot causing the fluid to overheat. Was the correct ULV fluid used during your previous service visit?

Yes the correct ULV fluid was used prior to me running on the track. It was also set at the proper level.

I am thinking of using the Royal Purple 12320 Max ATF High Performance Multi-Spec Synthetic Automatic Transmission Fluid or something similar?

https://www.amazon.ca/Royal-Purple-1.../dp/B000BQ4WZ2

Anything to help curb the high temperatures when I am at the track?

Has anyone else upgraded your tranny fluid?

[Chris 2018 ZL1 A10]

Are all the heat exchangers free and clear of any debris?

[Canadian ZL1]

Originally Posted by Chris 2018 ZL1 A10

Are all the heat exchangers free and clear of any debris?

I did leave my lic plate holder on the front. The thing is when I tracked the car last year I left it on as well and had no issues then.

https://zl1addons.com/products/camar...e-plate-holder

[Mikael]

in the gm performance manual the say its best do trive in D when tracking the car to avoid trans heat

[cdszl1]

Had one incident on track - got the meatball flag because the tranny fluid was spewing out and smoking off the exhaust. Had a nice puddle under the car after I made it back to the paddock. Turns out the dealer did not have experience with the A10 (very few do) and had overfilled it by about 2 quarts! They were stand up about it and made it right.

Lost confidence in the first dealer so I took it to another dealer and had to go over the proper procedure with them too. Just not many of these A10s have gone through the process yet I guess. I double checked it myself at home before the next event. I'd ask the dealer exactly what procedure they followed to determine proper fill level.

I have been to Road Atlanta several times since in miserably hot temps. No problem - not even a hint. Stays right in the normal operating zone. I do not paddle shift.

I called Chevy to discuss the ramifications of the overfill. They gave me a claim number but said that engineering indicated that it should cause no damage. Maybe they're right as I have had absolutely no issues since.

[SFV1LE]

Originally Posted by cdszl1

Had one incident on track - got the meatball flag because the tranny fluid was spewing out and smoking off the exhaust. Had a nice puddle under the car after I made it back to the paddock. Turns out the dealer did not have experience with the A10 (very few do) and had overfilled it by about 2 quarts! They were stand up about it and made it right.

Lost confidence in the first dealer so I took it to another dealer and had to go over the proper procedure with them too. Just not many of these A10s have gone through the process yet I guess. I double checked it myself at home before the next event. I'd ask the dealer exactly what procedure they followed to determine proper fill level.

I have been to Road Atlanta several times since in miserably hot temps. No problem - not even a hint. Stays right in the operating zone around 212. I do not paddle shift.

I called Chevy to discuss the ramifications of the overfill. They gave me a claim number but said that engineering indicated that it should cause no damage. Maybe they're right as I have had absolutely no issues since.

You're trans is probably fine, the overflow is designed to adjust for that and prevent damage. The fact that the flag ppl at the track caught it is good, so you didn't drive long with that condition.

Is there a trans fluid dip-stick? My Evo X MR (SST) didn't have one, the fluid level check was a ridiculous difficult process many dealers wouldn't even do.

[cirpower]

These are the temperatures I was getting on my ZL1 when running at the Heartland Topeka track in approximately 75 degrees F:

Max water temp 228
Max engine oil temp 280
Max transmission temp 243

Max boost 12.3

My engine is tuned and I am running Kooks headers. All runs were in D.

cheers
cirpower

[h018871]

I was at Cresson 3.1 in June with 100+ ambient temps, highest temps were seen during the second to last session
water 241
oil 289
trans 257

drove all day in D

I agree, in D the trans holds the gears longer which I feel pushed up the engine oil temps for me. I'm considering going to a lower thermostat. The trans and engine oils are both moderated by the radiator as well as have their own aux coolers.
I think Stephen has a good theory about too much fluid

[Badmojo]

I had pulled up some hot data for a 95 deg ambient day during an SCCA Time Trial.


Coolant Max 248 F
Oil Max 298 F
Transmission Max 241 F

[Exgermanowner]

Originally Posted by Stephen12ZL1

fluid level is likely too high & huge difference in temps in my car with the tranny in "D"...use the paddles as the car is very busy upshifting and downshifting a lot causing the fluid to overheat. Was the correct ULV fluid used during your previous service visit?

I am at the track with Stephen a lot and he has seen me experience this now in two different ZL1's. The first met it's demise, don't ask, but it was way overfilled from the factory.

The second and current car I'll add my own story - When I bought the car, I did two things - 1. Purge the air from the intercooler system. It definitely burped a lot of air and car pulls great, no issues on that front. My previous car I had a lot of issues. 2. Trans fluid - i got the car heated up to 210 on the temp gauge, got it up on jack stands while idling hot, checked the fluid. NO overflow - Oct 2019 zero issues at the track. Was out this past June and it started the mis- shift, sloppy slow shift crap again after 6- 7 laps. Guaranteed it's still over filled. The procedure is to get the car to 210F, but it really needs to be 240+ to really expand the heck out of it, but you can't do that on the street, at least not legally.