I have the new trans in and I have never had the temp sender in the hot line it was always in the pan. So how hot is normal in the hot line? What is the max safe temp? TIA

 

On a hot day sitting in traffic (no airflow, AC going) mine will tend to get to 180*F and hold there. At 180-190 the heat exchanger starts taking over so it should never be more than a little over the coolant temp. Locked up going down the road she runs 120ish due to no slippage. Sitting in neutral at long stop lights will help a little but not that much. Towing hard then backing up a hill will scare you with the temp. Over 240 and the fluid starts to break down.

 

I can get close to, and sometimes over, 250, on a hot day in traffic. Once I get moving it will drop quickly, and if the TC is locked it drops to 160.
I have been told this is normal. Generally the hot line will run around 180 in traffic, and slower than the TC being able to lock up.

Chris