hard shift/slipping

[6.4PSD]

while driving normal my tranny will slip or shift or somthing rightr at or around 40 mph and doesent feel normal at all????
my truck is bone stock

[6.4PSD]

is this normal or should i take it in or what??

[laynlow transport]

my truck and my buddys truck dose the same thing 2008 f530 ????

[6.4PSD]

YES 2008 f250!!

[laynlow transport]

i talked to the tranny shop they said its a sel stickn but not to change it till it dose it more cause there no dtc yet

[tcte]

What does it do? mine acts like 3 and 4 are the same gear, its shifts fine and doesnt seem to slip but the 3 to 4 shift sees no change in RPM but the truck is still moving under power, anything along those lines?

[laynlow transport]

Originally Posted by 6.4PSD

while driving normal my tranny will slip or shift or somthing rightr at or around 40 mph and doesent feel normal at all????
my truck is bone stock

i would take it in .....mine just wont go in to gear when u take off for a stop or u slow rite down to turn ....

[6.4PSD]

mine drives fine and is ok but it just does somthing weird at 35

[Mattf1987]

just to let yall know, eric at innovative informed me that these 6.4 trucks shift 1-2-3-5-6 on the upshift they only use 4th on the downshift and also 5 and 6 are the same gear one is just tc lockup

[tcte]

They shift 1-2-3-5-6. 5th and 6th arent the same that would make it a 4 speed. From my understanding it basically has 2 4th gears, one the ratio is off just a tad from the other, and is only used in place of the other one for a non-synchronous shift when the tranny is cold, cold like 0 degrees cold. they couldnt get it the shift timing for a good cold shift with the other one when the tranny is cold. if i recall the warm 4th gear is 1:1 and the cold 4th gear is 1.09:1. its kind of tricky to talk about because really going by the indicator 5th gear is OD and really 6th gear. and 4th gear could either be direct drive or the 1.09:1 gear.