Mine with the Dec 03 flash will lock up the TC and start the downshift sequence even when empty. In fact, I use the T/H mode to keep the truck under the speed limit as I coast down a steep hill (6 to 8% grade) on the way to work.

I have to be careful when I brake if the stop light mid way down the hill changes because it will actually cause the rear tires to skid when it downshifts. If it happens to be on a day when the road is wet (rare in So Cal) the truck can get a bit sideways because the road is also curved.

So while the T/H function has changed due to the Dec 03 flash on my truck, for the most part it still works.

Daryl

 

OK this is getting to be tuff….ug….yours works great!!!

 

I have a 2003 F550 that was reflashed with the December flash. Tow/Haul does work a bit different, but it still works. I get good engine braking even though the torque converter does not stay locked at closed throttle any longer.

I don't miss the terrible shift in Tow/Haul that sometimes screeched the tires at about 15 MPH.

 

Do you pull with your truck and if so what type of hills?

 

Mine has yet to be flashed and NEVER will be flashed. And mine will screech the tires downshifting at 15 or so. Have found this out, before you take off and put it in gear. Turn the tow/hoaul on before you put in gear and mine wont do it. If I forget to turn on then it will screach back tires. And will only do it the first time it downshifts

 

good point.When should you punch the tow/haul button. After starting the engine but before you put in gear, or after you are rolling?

 

I push mine before I put it in gear but after the engine is started. When I do push it after im rolling then it does the hard downshift and sounds like the tranny is gonna fall out, LOL

 

I have not tried this; I push mine constantly going down the road.
I never run it until I come to a hill halfway up and then always down, but never on the flat.

 

I seem to remember a post somewhere stating with the December changes the engine braking did not come on until speeds were below 45MPH. If your going more then 45MPH then you have to slow down first before the engine braking will kick in. At least thats what I remember seeing. I still have October flash and have not towed with mine yet hence can't say for sure either way.

 

I am going fishing down the coast this weekend. I will pull my boat. I'll play with it a little. Wonder what impact a Predator has on it?

 

I just got off phone with a FMC rep. We talked about my truck not having braking in
4th or 5th gear's he is to see if there is a fix {hope so} said he will call me Monday.
Will let everyone know how it goes.

 

GREAT if at all possible try as many variations as feasible,
i.e. engagements and speed and ….

 

not to mention fishing and a few cold beers.

 

Has anyone described in detail how to bait the hook with dynamite…………..to you.
Hope you can cast well

 

I pull a 21K triple axle fifth wheel. I routinley run through the Eisenhour tunnel west of Denver. It's 8% on the western side.

Tow/Haul will almost hold it to 30 MPH, which is the speed limit for trucks over 30,000 pounds. Since I'm right at that weight I follow that limit. About once per mile I have to use the brakes to slow the truck from 35 MPH.