I moved this to the Towing forum, since that's the subject of the thread.
I want to disagree just a bit with the advice about overdrive. My owners manual does not say to turn O/D off when towing. On page 185 of my owners manual, it says, "
Turn off the speed control." (This seems to be due to the fact that the speed control will easily disengage when climbing hills while towing. I correct for that by manually feeding gas on hills to prevent slowdown)
On the same page, it says: "
To eliminate excessive shifting, use a lower gear. This will also assist in transmission cooling." If I find that the transmission is starting to shift between 4th and 3rd, I lock out the O/D. If I find the transmission starting to shift between 2nd and 3rd, I move the shift lever into 2nd.
On page 202, the manual discusses driving with the O/D off. It says:
1. "Provides engine braking." I use this on long downhill stretches to control speed. I don't like to use the brakes. If I'm still using the brakes in 3rd gear, I drop it into 2nd.
2. "Use when driving conditions cause excessive shifting from O/D to other gears. Examples: city traffic, hilly terrain, heavy loads, trailer towing and when engine braking is required." Notice it is not talking about the Torque Converter (TC) here.
However, I really agree with you, 04FX4, in your philosophy. If I find the TC starting to frequently unlock and lock back up, I turn the O/D off. In any kind of driving, towing or not, I try to minimize gear shift and TC activity.
The temperatures you see, orygunf150, are perfectly normal. I have bigger tires, and I regularly see TFT in the 214-216 range during a long hill climb. The useful life of the transmission fluid is shortened. (Probably cut in half).
Engine temps in the 200-210 degree range are exactly what you want for efficient engine operation. This is where the engine is designed to operate. Don't try to get it to run colder. It can actually be harmful to the engine and will hurt your fuel economy and power.
One more thing, orygunf150. A toy hauler has a pretty high profile (big wind resistance). If you can stand to do so, drive slower when pulling it. In any case, don't go faster than 65mph, unless you have special high speed trailer tires.
- Jack