Controlling Tranny Temp

I am sure that most of you around here know this already, however, I have found that running the truck in 4th gear when towing and keeping the RPMs around 2500 makes a huge difference in the tranny temp.

I live in Arizona and on a recent trip to San Diego, I noticed this huge change. In Az, you can drive at 75 while towing, not that anyone would. That means that you can legally go at 70 mph in 4th, which gives you about 2400-2500 rpms if you are towing over 6K lbs or so. In my case, my tranny runs at around 160 degrees in very hot weather.

Now, as soon as I cross the AZ/CA border, I need to drop to 55 mph by CA law. That causes the RPMs to drop to 2100 while towing in 4th in flat. That makes the tranny run much hotter in the same weather. In my case, my tranny shoots to 185 in flats.

So, drive a little faster, keep your rpms at 2400-2500 and your tranny will run a lot cooler. In my case, I lose 1 mpg when driving [email protected] vs [email protected] My truck goes from 10.5 to 9.5 while towing 8500 lbs.

Mike