48re tow/haul on 04.5 and newer

[MikeBeggy]

OK,here goes. I am looking for some comparison between my 05 tow/haul operation and others with the same trans. I am trying to find out if mine is working correctly. The tow/haul button changes the trans as follows: when activated, the shift points rpm is raised. The trans still goes into overdrive and lockup. The stange thing is that when I want to use the engine braking feature, if I let off the go pedal with the tow/haul not activated, and then push the button, the trans will downshift and I get the engine braking to occur. However, if I am driving with the tow/haul on, and I let off the go pedal, no downshift unless I turn the tow/haul off and then back on again. At that point, again no acceleration, then the trans will downshift. It makes for kind of goofy use of the tow/haul feature to have to cycle it to make the transmission downshift. Has anyone else used theirs enough to notice if other trucks are acting the same? This is for 04. 5 and newer that have the PCM in charge of everything. Thanx for your time responding.

 

[Alan Reagan]

What mine seems to do is keep the TC locked up in the Tow/Haul which provides a noticeable amount of braking without downshifting. T/H holds the gears longer unless I'm using mild acceleration. Then it seems to shift at the same point as with T/H off.

 

[Hokey]

How do you or can you take it out of Overdrive? on the 05's.

 

[BNH4221]

How do you or can you take it out of Overdrive? on the 05's.

Feature deleted on 05 models. :{

 

[MikeBeggy]

The only time I can 'force' the trans to shift out of overdrive is when I'm decellerating and I hit the tow/haul button. Then it will engine brake until I touch the accel pedal and it shifts back into od. Is this the same as others with the 05's? Thanx.

 

[scootergmc]

Just to reclarify, the 04. 5's are not the same as the '05's. Pushing tow/haul locks out OD in 04. 5's

 

[zues]

Which is a better way to go the 2004. 5 or 2005. I have the 2004. 5 and if the 2005 is better, is there a way to reprogram the 2004. 5 to work like the 2005.

 

[CumminsWill82]

Yep same thing mine does, so far i like and BTW folks remember one thing ,this thing seems to be set for the ebrake that coming shortly for us slushbox guys. Why else would of DC gone with a full electronic control of the 48RE and scrap the old TV cable, so the ecm can control eng,trans shift and lockup, and ebrake.

My trans wont shift to OD until 40 mph under 40 it stay in 3rd locked up, It provides pretty good eng braking effect in city traffic. Once over 40 say 60 shes in 4th and if you brake she stays in 4th TC locked til 35 mph and then downshifts to 3rd un locked( if you touch the gas it will lockup in 3rd at point and stay locked til 25 or 30 mph) The more throttle the higher the shift points, half throttle shift in 4th is about 60mph. full throttle she do up to 3200rpm in 2nd & 3rd, Btw in Tow Haul she'll also lock up the TC in 2nd gear at times if not always its pretty damn hard to tell. Another possibility is that there are different ecm softwares and some are more aggressive that others, regardless this transmission with a eBrake will definetly will be a awesome combo better than the competion. Sorry for the long post

 

[pecandude1]

we need some help