2008 350 superduty v10 transmission problem

[jimsea]

Just got this 2008 with a v10 that has the tow/haul feature, seems when I am in cruise control it goes automatically to tow/haul as there is no difference
in down shifting weather I select tow/haul or not. When I am out of cruise control it works fine, select tow/haul and it downshifts for compression brakes out of tow/haul it does not downshift. I am hoping this is some small adjustment?

 

[rusty ol ranger]

Alot of newer vehicles will use the transmission to help control downhill speed with the cruise on. My guess is its supposed to be doing that

 

[adsm08]

Normal operation. The cruise control computer really only has access to the throttle controls and the trans shift schedule, it has no way of applying the brakes, so if it needs to slow the truck down all it has is engine braking.

 

[jimsea]

Sorry did someone say something about using the brakes to slow down, I spoke of compression brakeing, witch means using the engine to slow down, why are you bringing up applying the brakes?

 

[Dirtman]

For funzies...

 

[adsm08]

Sorry did someone say something about using the brakes to slow down, I spoke of compression brakeing, witch means using the engine to slow down, why are you bringing up applying the brakes?

I don't know if I should bother explaining it again, since you clearly didn't understand the first time, or just write you off as not able to understand.

The cruise control CAN'T USE THE BRAKES so it has to use compression braking if it needs to slow the vehicle, so you will notice more compression braking when using cruise control.

 

[rusty ol ranger]

Basically the cruise control is only "wired" into the throttle and transmission control. It only has power over those.

It has no power over the brake pedal. So therefore the cruise uses what it can control (throttle and trans) to slow you when needed.

 

[jimsea]

The question was in regards to the tow/haul feature in the v10 transmission that changes the shift points in the transmission

 

[rusty ol ranger]

More then likely its functioning properly.

 

[jimsea]

Thank you as you can see I don't post very often, there is always an expert who starts off with an innuendo about your mental capacity and then precedes to give you an answer that has nothing to do with the question, I visit frequently in general I can get my answers through search and reading and will continue to come to this forum for good information on my Ranger and now my E350 Super Duty van

 

[Dsetz]

Not sure I've ever ran both Tow and Cruise at the same time. Sounds like a gear hunting nightmare.
I don't believe the difference in shift points is very noticeable in these trucks. Unless you run tow/haul empty and watch your mpg(its worse).