I have a 91 F250 with an automatic transmission. I put a plow on it this year and have been having problems with the transmission overheating. I never had a temp gauge for the transmission so the only way i would know it was overheating is tranny fluid would start coming out and i would have to stop and let it cool down. Its fine for a little while but after about 2-3 hours of plowing driveways it will start to overheat. I put in a cooler and during the last 2 storms it was still overheating. Now i have a temp gauge in for the tranny. What temperature should the transmission be at normally and at what temperature should i give the transmission a break to let it cool down?

 

NOTHING over 220* and even that is a lil too warm for comfort

They say 70-100* above ambient air temp

 

Sounds like you need to plow in low range. That will stress the trans less meaning less heat. You're underpowered and straining the trans.
Low range, od off, in drive and let it shift.
Reverse will be slower, but it's an auto, it will go plenty fast for you.

What kind of cooler did you install. Was it a stacked plate style or a single pass loop style one. How big is it.

 

I actually had a shop install the cooler so im not sure what kind it is.

 

So what kind of numbers are you seeing?

 

The gauge was installed after the cooler so there hasnt been any storms yet with the gauge in so i have no idea what the temp was getting up to while plowing. The lowest temperature on the gauge is 140 and it doesnt get over that just driving without plowing.