HD Diesel ECU and towing

[eljefe]

I have the stage 1 delete. Bought used for a steal a few months ago. First time pulling a trailer with it I noticed with the tow/haul activated the truck would sometimes shift in to 8th gear. I thought when using tow/haul the truck would stay out of 8th gear? Temp numbers were never too high, so that was never the issue. Mostly just my observation.

No, transmission tune was not included….at least that I saw on the purchase paperwork.

 

[sirdumpsalot]

My truck will shift into 8th gear with tow/haul on, even before the tune

 

[sirdumpsalot]

i'm like 99% sure but I'll check this weekend for you, I'm towing my camper to Yosemite

 

[crash68]

First time pulling a trailer with it I noticed with the tow/haul activated the truck would sometimes shift in to 8th gear. I thought when using tow/haul the truck would stay out of 8th gear?

The Tow/Haul mode on the ZF 8spd does not lock out eighth gear with the stock trans tuning. Even with a 8K lbs trailer behind the truck it would shift into 8th. It's due in part to how fast your towing and the much lower torque peak of the EcoDiesel (2K rpms) compared to the Hemi(4K rpms). Even with the Hemi it will shift into eighth but will bounce right back out while towing.

 

[sirdumpsalot]

there ya go

 

[eljefe]

Thanks