A/T Tranny Temps
Senior User
Joined: Aug 2004
Posts: 352
Likes: 0
From: Racine Wi
Empty and towing less than 8000 lbs, I get about 60-70 degrees above ambient temperature. When pulling my 15,000 fifth wheel in the mountains in the summer, the temperatures can get up to 210, but when the temps want to climb higher than that, I back off to keep them below 210. There are alot of opinions on how hot is too hot, but I spent alot of money for my upgraded transmission and everyone will agree that heat is the enemy, so I am not taking any chances on cooking it. I also run a large aftermarket cooler and synthetic fluid to insure a long life. I would not recommend towing heavy without a temp gauge.
Logistics Pro
Joined: Jun 2005
Posts: 4,243
Likes: 16
From: AZ
I run a Tru-Cool 40k cooler and I run at least 70 degrees less than ambient. When pulling loads over 6000 pounds at highway speeds (60-70) I run almost consistently at 140 degrees 
...Here is the problem though - I have to be real careful of the tranny temperature when I am creeping over mountain passes in the desert. There just isn't enough air moving over the transmission cooler to carry off the heat. I am the most susceptible to high temps (200+) 
when I drive slow, pulling heavy loads in the summer. I now wish I had installed a cooler with an electric fan. This Spring, I am going to install a fan to take care of that problem.
...Here is the problem though - I have to be real careful of the tranny temperature when I am creeping over mountain passes in the desert. There just isn't enough air moving over the transmission cooler to carry off the heat. I am the most susceptible to high temps (200+) when I drive slow, pulling heavy loads in the summer. I now wish I had installed a cooler with an electric fan. This Spring, I am going to install a fan to take care of that problem.
Postmaster
Joined: Nov 2003
Posts: 3,595
Likes: 0
From: Utah County, UT
I usually run about 140-150 empty, doesn't seem to matter what temp outside is. Towing 12K fith wheel, I run about 180 doing 65 on interstate. I have the trucool 4739 installed up front. Just installed transgo reprogramming kit, will see if the temps are any lower this summer.
Posting Guru
Joined: Feb 2004
Posts: 1,873
Likes: 1
From: Phx, AZ
Empty here in the desert middle of summer (116 or so ambient) I see temps of about 135-150. Towing a large 5er up mountain grades etc in summer 155-180, usually about 160. Yes I have the tru-cool max. Before cooler I was seeing 180-210 towing and 150-165 empty.
