What is too hot for an auto transmission? Does anyone know what temp the the stock auto idiot light comes on at? Thanks for the help!

 

If the light goes on, its to hot.

Change fluid and install a tranny cooler.

 

Like an engine, I wouldn't run the oil over 250F for any significant length of time. ATF is mostly the same as a high-detergent 0 or 5 weight oil and will break down if ran at high temps for too long. In general, the ATF temp should run close to the coolant temp, plus maybe 10-20 degrees when under load.

As for when the light comes on, can't say as I don't have that info next to me.

 

I have the Inchworm adapter to gear drive transfer case. The stock temp sender was in the stock t-case section (which is gone) and I didn't see any other sender.

Filter and fluid was changed less than 5000 miles ago. I'm going to add a cooler when I figure out where to put it (my front bumper does not allow for much room, so I'm going to have to mount a fan assisted cooler towards the rear of the vehicle)

 

I have an Autometer gauge with the sender in the pan. After driving for a while (I live in the mountains, so there's always a hill or pass to climb) the temp seems to level out in the mid 220's. After a wheeling trip yesterday (on the highway), the temp climbed up to the 230's and I stopped to let it cool down. I would really like to figure out the when the stock idiot light kicks on, for a base point and general scale. Thanks for the info!