Auto-trans temp. Is too much cooling possible?

[MontrealBronco]

All right, I spent the last hour searching the archives on the subject. I just found out, althought I was suspicious, that you need to go around 160 as a normal operating temp. for a C-4. If my gage is correct, I barely go above 110, even in traffic.

I have a B&M large finned oil pan and a 12" x 12" oil cooler in front of the radiator. If I read the routing correctly, it's tranny - rad - cooler - tranny. Is this too much? The engine is running around 195-200 at idle and is sensitive to traffic. I was about to order the Hayden part's for the fan clutch upgrade to help it a little.

I was also thinking of removing the oil cooler to give the radiator more surface and run the radiator cooler only. After my reading, I have come up with these options:

A: Remove oil cooler, go stock.
B: Bypass radiator cooler but get a smaller unit to put in front of radiator.
C: Leave it alone and quit complaining.

Keep it mind I do not use the Bronco in the winter and this one only gets to see light wheeling, nothing too serious.

Jeff

 

[76 bronco J]

is the guage taking a reading from the pan ?- are you using a electric gauge if so I might be suspect about the calibration-- I would plumb the gauge to the pan if not there already & use a mechanical gauge for the best accuracy then proceed from there

 

[SaddleUp]

Yes, it is possible to run the tranny too cool however with the setup you have now I doubt this is the case. Try the above suggestions and make sure it really is running cool first.

 

[Solar Aviator]

Make sure you are getting accurate readings. Anything over 100 degrees F should not be a problem and viscosity of ATF is usually only an issue when it is really cold. When the transmission cools, air enters through the breather. It contains moisture. You want to run at a temprature that evaporates the moisture. Especially in the winter. A buddy in a Scout just torched one. $750!!! The ATF looked like mollases and smelled nasty. Be cool, be happy.

 

[broncnaz]

I doubt the fan clutch will make any differance in your traffic temps as all it does is enguage the fan when the temp is hot enough. Your fan is already turning when in traffic and your running hot so you'll gain nothing in traffic but could gain when at speed on the highway and the engine is running cooler the fan clutch will disengauge freeing up some power. You might try removing the external cooler see if it allows the engine temp to come down any and if the trans temp goes up any that will tell you whats happening quick. I suspect that your having a hard time drawing air through the cooler and radiator. I used to run a 4 core radiator and had a lot of problems with it running hot in the summer I dont think enough air was getting through the radiator part of it was that it was a crappy JD radiator I went back to a 3 row and it barely gets to 190 when wheeling real slow or sitting in traffic on a 100+ degree day.

 

[Mark]

The correct order of fluid flow should be: tranny-cooler-radiator-tranny.
The radiator will warm up the fluid before it goes back to the transmission.
It has a moderating effect.
If you bypass the radiator then your transmission fluid temperature will drop further.

I'd shoot for 125 - 140 degrees F. on your temperature guage. The fluid working in your transmission will be significantly warmer than what your guage reads.

 

[67EB_in_619]

you can buy a thermostat that will bypass the cooler (95%) until it hits 180* .. you can get them from summitracing for about $40

 

[MontrealBronco]

Well, I did it. I removed the transmission oil cooler and now the engine doesn't get above 190 and the transmission goes around 160-170 wich seems to be optimum from what you've all told me and read. Plus, I noticed that the tranny shifts are smoother now so all is well.

Jeff