Need some advice. When towing my 13K 5er, with the EB brake with Tow Haul on and slowing down or going down a grade as the EB kicks in/downshifts it jerks. How do I minimize the jerking of the trans and EB?

 

I was just asking this same question this weekend. The downshift programing with the "tow/haul" mode is pretty aggressive. I was told (haven't tried it yet) that on downhills you can cancel the "tow/haul" mode and just use the button shifter to downshift with the exhaust brake as you please. It won't harm the tranny. Like I said, I haven't tried it but I was told it will be okay.

 

Thanks Alaska, I was thinking I would try the same thing next tow, but was concerned about what damage if any could be done to the EB, engine or tranny. Who told you to try this?

 

to prevent the harsh downshift it usually will slightly press the accelerator pedal while it downshifts, not enough to prevent it from shifting, but enough so it doesn't snap my head off.

 

A friend (professional truck driver) who has a 2009 6.7 and tows a 26' trailer.

 

Try the manual shifting out of tow haul mode. Its not as aggressive. I use this mode too on long hills to keep it from trying to go to 3rd gear all the time.

 

I don't have an automatic, but I'll throw this out. Isn't the TC locked when in T/H while decelerating and unlocked when T/H is disengaged? It seems to me that turning off the T/H defeats the purpose of the EB, and would lead to increased tranny oil temps due to TC slippage. It seems to me that a better way would be to turn the EB off when downshifting, then turn it back on when in the right gear. I know that if I downshift with my EB engaged while the engine speed is decreasing to idle I can chirp the tires while unloaded. Not real good for the clutch plate to do that. I either match RPM to the transmission, or turn the EB off until my downshift is complete.

 

You could turn off the EB and the tow haul mode momentarily like real truckers do with manual trans to prevent the severity. Takes the pressure off the driveline while switching gears.

 

The converter will still be locked even with the tow/haul disengaged.