towing in the mountains

from what I understand most use tow haul mode when towing.

do you leave the truck in drive?

do you shift into a lower gear when going downhill?

 

tow haul and using s4 vs drive will keep the trans locked up more, lower trans temps and reduce the trans from shifting all the time.

 

Towing in S4 will keep your transmission cooler even on flat ground. I used to tow in D until i added the temp gauge.

 

I recommend any gear that keeps the rpm's about 2400. this could be s5 if doing 73mph.

 

Yup. And don't use cruise control. It basically overrides what Tow/Haul is doing. Your owner manual should say the recommended method is towing in D and using S4 for downhills to keep the batteries charged etc. Best thing you can do when towing is leave early and drive slower. If you can cruise along at 60-65 MPH that seems to be the sweet spot in my experience. Better MPGs and a pretty easy tow experience.

 

Scale says travel trailer weighs 4300. Only pulled it on 2 trips with the scan gauge. In D at 70mph it will run 212 on flat ground but climbs to 230 fast with the smallest incline.

in s4 it will stay 203-204 no matter what. I have not hit a massive grade yet though with it.


Interestingly enough i did just drive socal-black hills-montana yellowstone-home. Lots of grades. Even without towing S4 keeps the trans pegged at 203 regardless of grade at 85mph. In D it rose to 240

 

TH mode with any trailer. S4 on anything that might require a down shift in normal driving. So unless I’m on highway its s4. If on highway with steady throttle s5. Eliminating shifts and keeping torque converter locked are the keys to keeping a happy transmission.

 

Allison is comparing apples and oranges as you know.

I’m still dreaming for an Allison behind a Cummins in a ford chassis.

edit: a 6 speed Allison. Not this stupid 10 speed nonsense.

 

no i have the SG 2. Doesnt show if its locked or not. im pretty noise sensitive in hearing the engine while cruising(i know not scientific) however i think i can hear when it unlocks.

city/highway unloaded driving is normal to see 203 temp in the transmission torque converter consistently. It basically will hang there at all time until it unlocks in overdrive. Mine has a cooler too. I can’t imagine how fast the 19-21 heats up

 

On my '17 towing a 7800 lbs travel trailer, this has been my experience as well.