Installed a trans temp gauge last week and in about 60 degree weather the most it would go to was about 125. Now today in 73 degree weather I'm getting around 150. What can I expect come summertime and 90-100 degree humid heat? My LT came with the towing package and tranny cooler. I'm going to do the lti fan install sometime soon but these high temps can't be good on the 4l60.

 

It'll probably run at about 180 in the summer. They say to keep it under 200 for longer trans life.

 

Is the factory transcooler on a Z71 good enough?

 

My bird always ran 180 in the summer with a tranny cooler. I've always heard trying keep it below 210.

 

I would think so, my truck has the HD tranny cooler it says with the towing package.

 

Oh ok, I will have to see how it acts when it gets hotter. I guess 150 in 70 degree weather and hard driving isn't that bad then. Last fluid change I added Lucas Oil transmission additive/slip treatment. I actually noticed a difference from the moment I added it and drove it around. Defiantely a great product.