vanners.. trailer button?
- Thread starter LDB
- Start date
greg334
Veteran Expediter
It changes the shift patterns of the transmission to take advantage of the torque of the engine while it can give harsher shifts (read quicker).
Some versions of it lock out the overdrive gear while under a load to prevent overheating but with the allison and 6 speed slush boxes which have two overdrive gears, it seems to be an overkill.
When to use it?
Maybe when you are hauling something heavy or near your max rating.
Some versions of it lock out the overdrive gear while under a load to prevent overheating but with the allison and 6 speed slush boxes which have two overdrive gears, it seems to be an overkill.
When to use it?
Maybe when you are hauling something heavy or near your max rating.
Well, I took a novel approach. I read the manual. It says that's mainly for when the total weight is at least 75% of the GCWR which for my van would mean 10,500 pounds. That's 600 pounds over my gross so I guess for me it's a feature I won't ever need. It doesn't give the specifics of how it changes shift points etc. though which is annoying. It does say it could be rougher and also reduce fuel economy, which I expected.
So does mine! It's for engaging the tow/haul mode for the transmission.
When the tow/haul mode is engaged it will "stretch out" the shift points. The engine will rev higher before shifting into the next gear.
I use it when climbing steep grades and on hilly curving roads. It keeps the transmission in 4th gear longer, preventing the back and forth shifting between OD and 4th.
I also engage it when driving on snow and ice where my speed may vary between 45 and 60 mph. The transmission will stay in 4th eliminating an unwelcome downshift from OD.
If you have a tachometer, do some experimenting. Under normal acceleration my van shifts somewhere between 2000 and 2200 rpm. With the tow/haul mode engaged it will run over 2700 rpm before shifting.
My cell phone has a soft plastic cover over the USB port. On the cover is a picture of a one legged stick man carrying a bowling ball in one hand and a briefcase in the other. What's that all about?
That's where you plug in your IRT to English translator.