My 06' F-350 PSD, with the TS tranny I think it has some issues. The PSD runs great, but the tranny seems to shift kinda wierd,,lately when slowing down, when the truck gets to 20 mph,,I feel what seems like the tranny droping into low,kinda like a small bang,or bump,almost like hitting a pothole,,,but no hole in the road. Now it did not do this before,,truck has about 6700 miles on it now,,started to notice it around 5 k miles.

When in Tow/Haul mode,,how many times does it shift down when stopping ?? On my truck say I click T/H on after a couple seconds I feel it start to brake/slow the truck,,then when I get to about 30 mph,,it will shift down once,,thats it,,,,,Is this how they all act,,,or do they shift down twice ??

The other day I see traffic ahead slowing,,I click T/H on, truck slows I get down to about 20 mph,,give it some fuel let off, fuel it again,,and bang, it drops into low,and I mean a hard bang, first time it did this,,, just twondering how all your T/S tranny's act,,going in for oil change around 7 k,,will have them check it out then,,sorry for the long post. Later,,,Mark

 

Mine does the same thing when in tow haul.But not in normal driving.
Its actually helping you brake when in t/h with a load on.

Rich

 

My 06 after stop seems to stay in low gear and than it will surge out of it. This isn't always only now and than. I have 3300 miles on it. I mean it sounds just like it's in "grannie gear". Than all is fine. This is with no load.


Also I'm curious as to why you'd put it in Tow/Haul during braking? My understanding of the entire system was that the truck would act as a part of the braking system so that your not putting undue strain on the entire system.

 

Do you guys notice any difference in full throttle shifting between OD and T/H? My 5.4 seems to shift more positivly in T/H, but at a few hundred less RPM.

 

My 06 did this too. i could feel it downshift from 2nd to 1st gear when coasting to a stop. the dealer reflashed the computer and it has never done it again.