Tranny temp.

What range of oil temperatures would you expect to see in the tranny reservoir.. I’m not trusting this dumby gauge. Sent a temperature prob down the dipstick tube after gauge was reading hot and came up with 239degrees in the reservoir.. this is a powershift dresser td15e. I would think there is a universal temperature that a reservoir should not exceed. It seems hot to me. After it leaves the torque converter it must be at least 250 degrees before it goes through the cooler