What is the proper procedure to follow when you are towing up a mountain highway in tow/haul and the trans temp starts to climb up to where you are getting concerned about it i.e. 230. I have a 2005 D...
Add another cooler. I added a trucool rated for a 40K gvw vehicle to my Ford and can't make it get hot on 6/7% grades with toyhauler in 100+*. 230 is getting to the point of concern. If it's been that hot a fluid change would be in order.