Question for our Automatic Transmission Experts.

[Larry E.]

Simple question. What would be the normal operating temp. for the fluid for the Corvette automatic transmissions? What

would be the "red zone" where we would have to start thinking that there may be a problem? Thanks in advance. Larry

[Jake D.]

Re: Question for our Automatic Transmission Experts.

Larry-- We have a 2012 Suburban with the tow package. We usually tow a 3500 Lb. boat. Last Sunday we went up to Lake Geneva Wisc. It was 90 degrees and we had 4 passengers and all their gear. The trans temps were 144 to 170. Never higher than 170. I would think if the trans temp ever got to the 300 degree mark it would trigger a message on the DIC. I know this is not a Corvette, but the temps would be similar.

[Larry E.]

Re: Question for our Automatic Transmission Experts.

Just an update: I have ask this question to 4 Chevy Dealerships and gotten 4 different answers. Does 300 Degrees as mentioned above seem correct to
everybody?? What does Duke W. or Joe L. think; as their opinions are as good as anybodys? IMHO Larry

[Terry M.]

Re: Question for our Automatic Transmission Experts.

I don't have the books here at work, but there are a series of transmission books published by Motor Books International. I have their How to Rebuild a Turbo 350 and [i]How to rebuild a TH 400[i]. Neither is in a very accessible location. Both books have sections on augmenting the transmission cooling system and adding a transmission fluid temperature gauge. I think, even though it has been a while since I looked at those books, they mention maximum trans fluid temperature ranges.

I am pretty sure they also have a Powerglide book. The maximum fluid temperature would be the same for all of those transmissions because it is dependent on the trans oil. Once the oil deteriorates its lubricating abilities go bad and it really doesn't matter what kind of transmission that fluid is in.

Edit add:
Just for S & G I Googled "ATF maximun temperature"
THese are just a selection of the many responses I got. I selected GM oriented responses and avoided 4x4 sites, but I expect a survey of those will yield similar results.

http://www.bobistheoilguy.com/forums...Number=1705531

http://www.forestriverforums.com/for...ture-9989.html

http://www.silveradosierra.com/transmission/maximum-tranny-temp-t1877.html

Try that Google search. You'll like it.

[Larry E.]

Re: Question for our Automatic Transmission Experts.

Thanks Terry; was surprised to see the amount of different opinions on this subject. Larry

[Terry M.]

Re: Question for our Automatic Transmission Experts.

Thanks Terry; was surprised to see the amount of different opinions on this subject. Larry

Well; you DO know what opinions are like.
I would tend to put some stock in what the transmission engineers posted. If anyone knows they should be the ones.

[Jake D.]

Re: Question for our Automatic Transmission Experts.

On page 5-50 (Instruments and Controls) of the 2013 Corvette Owners manual it states that if the automatic transmission fluid temperature rises above 270 degrees, the DIC will display - TRANSMISSION HOT--IDLE ENGINE, and you will hear four chimes. When the transmission fluid cools to 230 degrees, it is considered safe to drive.

[Steven B.]

Re: Question for our Automatic Transmission Experts.

Going from memory when I used my TH400/L-82 for track days and auto X'ng normal driving temp was around 200 on the street, track 1st and 2nd gear with B&M kit holding it in gear never got over 240-250 running through the stock cooler and using stock converter with 3.55's and 3.90's. Steve