Topic: How Hot is too Hot - Transmission Fluid

Ok..Just finished NJMP and the Cordoba did great . No reliability issues. But -  I am still concerned about the transmission Temp. I have a temp sensor in a  transmission port ( not the pan) and the max temp I got was 185 degrees when I was driving on Sat. Another driver had her up to 200 degrees on Sunday and he was beating her pretty hard.  I do have a big cooler on it and have bypassed the in rad cooler. Is 200 degrees OK.? My on line research seems to point out that 200 degrees is acceptable , but they dont want much more. Do you all agree?   I could put a bigger or additional cooler on it but space is begining to be an issue in front of the rad ( also have a big engine oil cooler -  engine oil never goes above 180) .  Maybe I could put an air dam / spoiler below the bumper ? Also - I dont want to over cool the trans.

Your thoughts comments are much appreciated!

Re: How Hot is too Hot - Transmission Fluid

My tow rig has a trans temp gauge and the red section doesn't start until 260.  I think 200 should be fine, even 220 or so.  Fluids now are better than when that car was made.  You can also have a sample of the fluid tested by an oil analysis sort of place like Blackstone and have them give you an idea of the health of the fluid (and potentially the trans itself).

Chris from 3 Pedal Mafia

Re: How Hot is too Hot - Transmission Fluid

As always...thanks Chris. I dont want to fix what aint broken....theres plenty of real broke stuff to spend time on.

Re: How Hot is too Hot - Transmission Fluid

in general.... over 200 is bad for an automatic.    180 - 200 is great, the problem with over 200 is the plastic and rubber in the transmission isnt real happy.

Re: How Hot is too Hot - Transmission Fluid

200 doesn't seem that high. Do you still have your ac condenser? When we were running an auto we used that as our cooler. A stick in that car would be sweeeeet.

"get up and get your grandma outta here"

Re: How Hot is too Hot - Transmission Fluid

200 is about as high as I would be OK seeing.   220 is sweating pretty hard, and 260 is when things start to go bang.  This is what we saw with our Camaro racecar, which also had the sensor mounted in the cooler line.

That being said the trans will last longer if you keep things around 190ish, now if its a hot day there might only be so much you can do about it other then back off for a bit and see what happens. 

The air dam idea works great!  The last 5 cars Ive built all have them and they helped pull a ton of heat out of the engine and the trans.  This was especially true with bottom breathers like our Camaro and Corvette.  Only takes a bit of sheet metal and a few braces to do on most cars.  Also another trick that worked well for us was to seal the coolers/rad to the nose of the car.  Air often will want to spill around a big thick radiator/cooler by sealing it up to the nose the car you will push more air though it and again drop a few more degrees for very little work done.  Sheet metal, furnace tape, and good to go.

Team Sucker Punch:Winner Org Choice award Were the Elite Meet to Cheat 2015
Chevy Camaro (Tiger striped #38)  (1989-2017 RIP old friend)
Chevy Corvette 1984......and still racing!

Re: How Hot is too Hot - Transmission Fluid

when we were running an auto in our 84 T/A (700r4) we used the AC condenser as the cooler, never had an issue.

"get up and get your grandma outta here"

Re: How Hot is too Hot - Transmission Fluid

We used an external trans cooler and  the radiator cooler.  If the radiator cooler is there, why not use it too ( other than another failure point )?

COM ( Chief Operating Moron ) of Burnt Rubber Soul Racing
Current fleet: 95 Ford Probe, 81 Mazda 626.  Past: 81 Imperial
Facebook page:  https://www.facebook.com/burntrubbersoulracing

Re: How Hot is too Hot - Transmission Fluid

best is to inspect the fluid, see if its cooked or getting cooked. Than you can establish if its okay or not okay. Because the point of temperature measurement makes a big difference. So its case by case kind of deal.

https://www.facebook.com/greatglobsofoil/
This car....Is said to have a will of it's Own. Twisting its own body in rage...It accelerates on.
1978 Opel/Buick Isuzu(B) - IOE, C class, Incredible Feats in Badge Engineering; 1996 Ford Probe GT(B)

Re: How Hot is too Hot - Transmission Fluid

majo wrote:

We used an external trans cooler and  the radiator cooler.  If the radiator cooler is there, why not use it too ( other than another failure point )?

There can be a problem with using the trans cooler in the radiator. If the car is running on the hot side for what ever reason, say over 200 deg. then your not helping the trans fluid by using the radiator to help cool the fluid. Better to do as some have said, use the AC condenser and bypass the radiator cooler. The only time I would use the radiator trans cooler is if your racing where the air temps are below 50 deg. and there have been a few Lemons races run in even colder temps.

Re: How Hot is too Hot - Transmission Fluid

FWIW we used tractor hydraulic fluid in ours. I cannot recall the make/number but it worse very well and doesn't burn up like ATF. It isn't DOT legal and isn't dyed red. I can find out the exact application if anybody wants to know.

"get up and get your grandma outta here"